There’s a patch of the North Atlantic, south of Greenland, that’s been getting colder for decades while almost everywhere else in the ocean warms up. This week, with more than 100 million Europeans sweating through temperatures above 35°C, scientists were pointing at that cold patch of sea as one of the reasons the heat sat on the continent so hard.

That cold blob is where we’ll start. This week I’ve got three for you. The cold blob and the heatwave it might be feeding, a billionaire putting $260 million into ocean protection just as governments pull back, and a trip off Brazil that turned up 31 new species in a fortnight. Two quick hits and a hard truth after that.

Deep Dives

A cold patch of the North Atlantic keeps bucking global warming, and scientists think it’s making Europe’s heatwaves worse.

The patch sits south of Greenland and Iceland, and it’s been a puzzle for years. While the rest of the ocean has warmed, this bit of the North Atlantic has actually cooled, by up to around 0.9°C since 1900. Scientists call it the cold blob, or the warming hole. This week, with a heat dome parked over Europe, a few of them were out explaining how a cold patch of sea can help cook a continent.

It works through the jet stream, the fast river of air that runs west to east across the Atlantic and sets a lot of Europe’s weather. Where the cold blob meets warmer water, that sharp difference in temperature changes the air above it, and it can leave the jet stream slower and wavier. A wavier jet stream is more likely to park a big high-pressure system over the continent and hold it there. Marilena Oltmanns, a physicist at the University of Bremen, describes the cold front as a kind of guide, bending the jet stream north so it loops around Europe instead of crossing it, with a heat dome settling in behind.

The evidence for all this is suggestive rather than settled, and worth being honest about. A 2016 study found that cold patches in the Atlantic were a common forerunner to Europe’s big heatwaves going back to the 1980s. A 2023 study at Germany’s GEOMAR institute ran the climate models with and without the cold blob, and got longer, fiercer heatwaves when it was in the picture. Gerard McCarthy, an oceanographer at Maynooth University in Ireland, was careful about it this week. A cold Atlantic is no “get-out-of-jail-free card” on global warming, he said, and some of the hot extremes can be made worse by the blob.

What actually causes the cold blob has been argued over for a while, and a study last month had a go at settling it. A team led by Stefan Rahmstorf at the Potsdam Institute for Climate Impact Research, writing in Geophysical Research Letters, reckons the cooling comes mainly from ocean currents bringing less heat into the region, rather than heat escaping off the sea surface. That same team reads the slowdown as an early warning that the Atlantic Meridional Overturning Circulation, the conveyor of currents that carries warm water north and cold water south, is weakening. I’d flag the same caution we did back in Deep Brief #36. Plenty of scientists are worried about which way this is heading. The precise timing of any tipping point, though, still has no confident date, and Rahmstorf is one of the more alarmed voices on it.

If you’re in Britain or Europe living through this week, the unsettling bit is the loop. Greenland’s ice melts and pours freshwater into the North Atlantic, that helps cool the blob, the cooler blob shifts the currents and the air above them, and that seems to push European summers hotter still. Europe is warming faster than any continent on Earth, and a patch of cooling sea might be part of the reason.

Michael Bloomberg has put $260 million into ocean protection, aimed straight at the gap between what governments promise and what’s actually in the water.

Picture a stretch of ocean marked as protected on an official map. Now picture a trawler dragging its net along the seabed inside that same line, perfectly legally. That distance, between protection on paper and protection in the water, is what Bloomberg’s money is going after.

On 23 June, at the Earthshot Prize Impact Assembly during London Climate Action Week, Bloomberg Philanthropies announced the $260 million to expand its ocean work. The idea is to help close that gap between what’s been committed and what’s been done, with some of it going towards enforcing the High Seas Treaty, the UN deal that came into force in January 2026 and, for the first time, lets countries create protected areas out in international waters.

The numbers underneath are what make it urgent. Governments have a shared target, called 30x30, to protect 30 percent of the ocean by 2030. The World Database on Protected Areas, which tallies up what governments report, now has coverage at around 10 percent. The Marine Protection Atlas, run by the Marine Conservation Institute, looks at how much of that is actually managed well enough to keep the destructive stuff out, and it comes to 3.3 percent. Out on the high seas, which are more than 60 percent of the ocean, barely 1 percent is protected at all.

To be fair, designating a marine protected area is a real legal step, and the reported coverage genuinely has climbed over the last decade. The trouble is that a line on a chart and a proper no-take reserve in the water get counted exactly the same in the headline figure, even though only one of them actually keeps a bottom trawl out.

The timing of his pledge is pointed. It lands just as the US and UK are trimming money for climate, nature and science, the UK while scrambling to find more for defence. The UK hasn’t walked away from the ocean, to be clear. A week earlier, at the Our Ocean Conference in Mombasa, it put up £13.9 million in new Blue Planet Fund money, and it can point to more than £86 million for those programmes since 2021. Even so, Bloomberg’s one pledge is worth more than ten times that latest UK chunk. Over in the US, Lance Morgan, who runs the Marine Conservation Institute, reckons recent moves to allow commercial fishing in four big Pacific marine national monuments, which the administration says is about restoring access for American fishermen, could knock up to 0.7 percent off the share of fully protected ocean, if they survive the legal challenges coming at them.

A private fortune plugging a hole that public money is backing out of is a mixed thing to celebrate. The $260 million is real cash for monitoring, enforcement, and the slow, dull work of turning lines on a map into protection that holds, and it’s there partly because governments have left the room for it. The hard part is the thing the money is aimed at, which is keeping a trawler on the right side of a line once someone’s drawn it.

A two-week trip off Brazil turned up 31 new species, and let scientists watch deep-sea cells build their skeletons live on the ship.

A few hundred metres down off the coast of Brazil, a siphonophore drifts in the dark, a string of glassy clones that each do one job for what is really a single hunting animal. A laser scans it without ever touching it, building a 3D picture while it carries on swimming. The same fortnight turned up a fast-swimming gossamer worm, nine kinds of jellyfish, and a single-celled creature big enough to see with the naked eye.

In two weeks at sea, a team aboard the Schmidt Ocean Institute’s research vessel Falkor confirmed 31 species new to science. They were working in the ocean’s midwater, the huge stretch of water between the sunlit surface and the seafloor, which is the biggest living space on the planet and one of the least explored. Most of the animals down there are soft and jelly-like, and they fall apart the moment you haul them up in a net, which is a big part of why we still know so little about them.

The speed came down to the kit. Instead of collecting animals and describing them in a lab years later, the team imaged them where they live, using laser scanners and a shadowgraph camera bolted onto a remotely operated submersible. On board, a microscope they’ve nicknamed the Squid let them watch the living cells of a single-celled organism in 3D as it built its glass skeleton, something the institute says had never been done at sea before. Sequencing the genomes on the ship itself turned identifications that usually take years into confirmations made in days.

Karen Osborn, the chief scientist, has spent her whole career on these animals and still, by her own account, feels like she’s only getting started with them. The team reckons the pace of discovery might be a record.

There’s a governance edge to this as well as the wonder. The midwater is exactly the zone that proposed deep-sea mining and midwater fishing would disturb, and it’s hard to weigh up the cost of wrecking a habitat when you haven’t even named most of what lives in it. Every fortnight like this one widens the gap between what’s actually down there and what any rulebook has got around to accounting for.

Two honest caveats. The 31 are confirmed new by the researchers, but the formal write-ups, the bit that makes a species official, still have to be published. The findings were actually announced earlier in June, reaching a bigger audience this week through the Guardian, so this is a story coming back round rather than breaking. The animals, and the sheer amount still unnamed below the surface, are real either way.

Quick Hits

Ocean people gathered in London this week to make the case that the sea belongs in the middle of climate talks, not off to one side. The session, run by the Commonwealth Secretariat and the UK government during London Climate Action Week, was really a warm-up for COP31 in Antalya, Türkiye, and the Commonwealth summit in Antigua and Barbuda, both coming in November. The Commonwealth’s Secretary-General, Shirley Botchwey, pointed out that 49 of the bloc’s 56 members have coastlines and 25 are large ocean states, and warned that the sea is soaking up the costs of a warming planet at a rate that can’t be sustained. One of her three priorities was turning commitments into projects you can actually invest in. The honest measure of a session like this comes later, in whether the money everyone urged in June has actually moved by the time those November summits roll around.

A study mapping where ocean plastic actually harms wildlife suggests we may be cleaning up in the wrong places. The work, published last year in Nature Sustainability by Zhang and colleagues and flagged this week by the European Commission’s science service, compared where plastic collects with where animals actually live. The big garbage patches often sit where few animals are, so they may matter less than their reputation suggests. The north-eastern Atlantic, by contrast, is a real hotspot, with animals far likelier to get tangled near coasts, more than a hundred times likelier than out in the open sea. The authors flag a catch with ‘biodegradable’ gear, which breaks into bits that are easier to swallow, and note the model measures relative risk rather than absolute. It lands while the UN’s plastics treaty stays stuck, with informal talks in Nairobi from 30 June and no agreed text after two failed deadlines.

Hard Truth From The Sea

What stays with me from this week is the heat. The ocean has quietly soaked up something like nine-tenths of the extra heat we’ve trapped, which is a big part of why a brutal week in Europe wasn’t far worse. It’s been carrying that for decades, steering our weather, holding more life than we’ve ever counted, and getting pledges and maps back in return. The sea we call ten percent protected, and actually protect about three, is the same sea keeping the rest of this summer survivable.

One more thing from me this week. My latest article for Oceanographic Magazine is up: The Flamingo Revolution, on the loggerhead turtles nesting along Albania’s protected Vjosa-Narta coast and the luxury resort development rising near them. It is the public half of a longer Ocean Rising investigation landing soon for paid subscribers.

Paid subscribers fund the reporting that tracks what is changing in the ocean and who is responsible for protecting it. Please consider upgrading to a paid subscription.

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See you next week.

- Luke

It’s Tuesday evening, and this afternoon I had to collect my son from nursery early, because it had got too hot for him and he’d had enough of it. We came home, filled the paddling pool, and cracked open a box of ice lollies.

The hard part is still ahead. Tomorrow and Thursday, the Met Office expects at least 39°C across much of England, under a red warning, and the June record set back in 1976 is likely to fall before the week is out.

This is also the week of London Climate Action Week. Thousands of people, room after room across the city, handed over to a single question: a warming world, and what we intend to do about it. I was meant to be there on Friday. I’m no longer sure I’ll make it.

I’m not the only one. Over the past couple of days, I’ve spoken to a few people who should be in those rooms and won’t be, kept home by the very thing the week exists to fight. Their children’s schools have closed, hundreds have across the south. Nurseries have rung them, the way my son’s rang me. Rail companies are telling people not to travel on the hottest days unless they must. People who have given their working lives to this are spending this week of all weeks at home, filling paddling pools and refreshing the forecast, shut out of the conversation about the fight by the fight itself.

It’s a small thing, in the scheme of it. A few missed panels. A larger absence sits inside it. For all the attention the heat is getting this week, the maps, the records, the warnings, the thing absorbing almost all of it gets the least attention of all.

Go down to the coast over the next few days to cool off and the sea won’t have got the memo. It will be cold, properly cold, cold enough that the RNLI is warning about cold water shock, the gasp that can drown a strong swimmer in the first minute. Record heat in the air, water cold enough to be dangerous, both true on the same beach.

That cold surface fools you. While the top metre stays cool, the same still, sunlit weather that’s about to roast the land will be pouring heat into the sea beneath it. High pressure, no wind, hour after hour of sun is exactly how you cook an ocean from above. In 2023, this set-up pushed sea temperatures around the UK and Ireland to extreme levels, as much as 5°C above normal off the west of Ireland, where NOAA rated the marine heatwave beyond extreme, the top of its five-point scale. Heat that feels survivable on a beach doesn’t go anywhere. It sinks, and the sea keeps it. The ocean has taken up more than 90 percent of all the extra heat we have ever trapped. Most of global warming isn’t in the sky we keep looking at. It’s in the water we don’t.

There is life down there with a stake in all this, too. Take the white-beaked dolphin, one of ours, a stocky character with a short white beak that has worked the cool seas around Britain since the ice left, tens of thousands of them in the North Sea. It’s a cold-water specialist, which is the trouble. It avoids warm water, and as our seas have warmed, it has been backing north, edging off the bottom of its own range, while its warm-water cousin, the common dolphin, moves up into the space it leaves. Off Scotland, researchers have watched the swap since the 1980s. It can swim away from a hot summer, which is more than a kelp forest can manage, but only while there is colder water to swim to, and for the dolphins in the southern North Sea, the map eventually runs out.

The odd thing is how little we watch any of it. For human heat we have built something serious: graded warnings, alerts to every hospital and care home, schools and nurseries deciding it’s too hot for children, all of it working hard this week and rightly so. For the sea, almost none of that. It is only fair to say why. Heat kills people fast, and a system that protects them first has its head screwed on right. The sea is harder to watch, and newer to the science. The gap is startling all the same. It took a recent piece of work at the National Oceanography Centre to give us the first proper map of where marine heatwaves are likeliest in British waters. We are an island, and we drew that map about five minutes ago.

The dolphins, for their part, have been filing a report nobody commissioned. UK researchers have taken to calling cetaceans sentinels, animals whose comings and goings reveal what a warming sea is doing to the life in it, in a way no instrument can. Where the white-beaked dolphin stops turning up, the water has crossed a line it couldn’t hold. It is as clear a voice on a warming world as anything you’ll hear in London this week, and it isn’t in the room either.

This evening, my son has been sun-pink and delighted, sticky with melted ice lolly, cooled by a hose and the people who love him. The sea gets no such care, and hardly anyone is looking.

When the marine heatwave data for this week is in, Ocean Rising will publish what the sea actually did while the country watched the sky.

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The whaling vessel Hvalur 9 shot two fin whales overnight. The animals were the first hunted in Icelandic waters since 2023.

Iceland’s Minister of Industries, Hanna Katrín Friðriksson, has said in public that commercial whaling is not in the national interest, and her government has committed to legislation to end it. She has also said that nothing could be done this summer to stop Hvalur, and that a bill would be introduced when parliament returns in the autumn. Two fin whales are dead this morning in the gap between those two statements.

The license sits at the centre of that gap. In December 2024, Iceland’s interim government issued Hvalur a five-year permit covering 2025 to 2029, a decision heavily criticised by most parties in Iceland. For 2026, the Marine and Freshwater Research Institute advised a ceiling of no more than 150 fin whales and 168 minke whales to be killed.

The minister’s position has a defensible basis. A whaling license is a legal instrument, and revoking one mid-term is not the same as declining to issue it. Unilateral revocation could expose the state to compensation claims from a company that already litigates over halted seasons. Even IFAW, which opposes the hunt, has acknowledged that any change in the law may only take effect when the current licence expires. The lawful route to ending whaling may genuinely run through primary legislation, and primary legislation may genuinely have to wait for the autumn session.

What the government has not done is explain why a practice it calls indefensible remains lawful enough to kill an endangered animal this morning. At the same time, the remedy waits for a parliamentary calendar.

Fin whales are the second-largest animals on Earth, after blue whales. The IUCN Red List classifies them as vulnerable to extinction. They mature slowly and reproduce slowly, which means populations recover slowly from hunting pressure.

The method is contested on welfare grounds, by Iceland’s own regulator. A report by the Icelandic Food and Veterinary Authority on the 2022 season found that 41% of whales did not die immediately, took a median of 11.5 minutes to die, and in some cases survived up to two hours after being struck, findings the authority concluded were inconsistent with Iceland’s Animal Welfare Act.

The commercial case for the hunt has thinned. Japan, historically the only export market for Icelandic fin whale meat, has scaled back its purchases as its own whaling capacity has grown, and meat from the 2023 season has reportedly gone unsold. Whether any of this changes the minister’s hand is now a question for the autumn.

Iceland is one of three countries, with Norway and Japan, that still permit commercial whaling. A national referendum on restarting EU accession negotiations is scheduled for August. The European Union opposes commercial whaling. The bill to end it has not been written.

Two fin whales were killed before any of that was settled.

On Thursday, the Trump administration reversed its decision to dismantle the Ocean Observatories Initiative, a $368 million deep-sea monitoring network that provides real-time data on currents, storms, oxygen levels, and ocean chemistry from instruments anchored across the Atlantic, Pacific, and Southern Oceans. The reversal came after a bipartisan group of ten senators demanded the National Science Foundation back down.

Two weeks ago, this newsletter covered the global network of Argo floats that tracks the state of the ocean and warned it was being allowed to decay. This week, the US nearly lost an even larger piece of that infrastructure before Congress intervened. That story opens a Deep Brief built around the Our Ocean Conference in Mombasa, where Fiji and Panama launched the first international initiative to protect the ocean’s twilight zone, and where the EU and UK pledged a combined half a billion euros in new funding. Meanwhile, Norway approved funding for the world’s first ship tunnel through some of the roughest coastal waters on the planet. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

The Trump administration tried to dismantle a $368 million ocean monitoring system. It took ten senators to stop them.

The Ocean Observatories Initiative is a network of anchored and mobile instruments that has been measuring the deep ocean continuously since 2014. Its arrays sit in the Atlantic, Pacific, and Southern Oceans, collecting real-time data on temperature, salinity, oxygen, carbon dioxide, currents, and biological activity at depths that no other US system monitors. The programme cost $368 million to build, is coordinated by the Woods Hole Oceanographic Institution in collaboration with Oregon State University and the University of Washington, and costs roughly $48 million a year to operate.

In early June, the National Science Foundation announced it would dismantle the entire network, beginning with the removal of instruments from the Endurance Array off the Oregon and Washington coasts. The agency described the decision as part of a strategy to take a “nimbler approach to prioritizing support for evolving scientific priorities and emerging technologies.” Scientists disagreed. The Endurance Array provides data that feeds directly into National Weather Service forecasts, Coast Guard search-and-rescue operations, and monitoring of harmful algal blooms and El Niño events that affect fisheries, agriculture, and coastal safety.

The timing was particularly alarming. An intense El Niño event, accompanied by an associated marine heatwave, is expected off the US West Coast this summer. Removing the instruments that track those conditions in the weeks before they arrive would have left forecasters working blind. Hilary Palevsky, an oceanographer at Oregon State who uses OOI data in her research, told Eos there was “a lot of real concern” among the scientific community that the Endurance Array was being dismantled just as the event it was built to monitor was arriving.

On 15 June, a bipartisan group of ten US senators, led by Democrat Jeff Merkley of Oregon, sent a letter to Brian Stone, the acting director of the NSF, demanding a reversal. “The OOI system delivers crucial information about our ocean patterns and weather, reaching and touching all Americans,” the letter read. “The effort to dismantle this vital network, jeopardizing decades of prior research, must be reversed in order to prioritize public safety.”

On Thursday, the administration backed down. The instruments will remain in the water.

The reversal is welcome, but the pattern it reveals is not. This is the third time the Trump administration has attempted to cut funding for US ocean monitoring systems. Previous budget proposals sought to eliminate the Integrated Ocean Observing System, the separate $48 million coastal monitoring network, before Congress restored its funding. The Heritage Foundation’s Project 2025 policy blueprint, which has guided much of the administration’s approach to federal agencies, recommended that climate and weather research across the government “should be disbanded.”

For readers who followed Deep Brief #41’s coverage of the global ocean observation network and the pressure it faces, this story is the US chapter of the same problem. Continuous ocean monitoring is the infrastructure that weather forecasts, climate projections, and fisheries management depend on. It generates no profit. It has no constituency that lobbies for it. When budgets are cut, it is among the first things to go, and nobody notices until the next forecast goes wrong or the next marine heatwave arrives without warning.

Fiji and Panama have launched the first international push to protect the ocean’s twilight zone. It happened at the same conference where the EU pledged €338 million.

At the Our Ocean Conference in Mombasa this week, Fiji and Panama launched the Mesopelagic Zone Conservation Challenge, a call to governments worldwide to take concrete action to protect the layer of ocean between 200 and 1,000 metres deep, commonly known as the twilight zone.

This layer is too deep for sunlight to support photosynthesis and too shallow to qualify as the deep sea, which has left it in a governance blind spot. It sits below the jurisdiction of most fisheries management and above the attention of most deep-sea policy. It is also, as this newsletter has covered repeatedly, one of the most ecologically important parts of the ocean.

Every night, billions of tonnes of small animals rise from the twilight zone toward the surface to feed, then descend again before dawn, carrying carbon with them. This daily vertical migration is the largest synchronised movement of biomass on the planet and a significant driver of the ocean’s capacity to absorb atmospheric carbon dioxide. The creatures that live in this zone, lanternfish, squid, krill, and bristlemouths among them, are the primary food source for commercially valuable species above them. Off the Kenyan coast, where hundreds of local fishermen depend on tuna and swordfish for their livelihoods, Ocean Conservancy analysis released alongside the Mombasa announcement found that mesopelagic species make up as much as 81 per cent of swordfish diets and 46 per cent of yellowfin tuna diets. Kenya’s tuna and swordfish industry reported earnings of $3.3 million in 2023. The twilight zone is where those fishermen’s catch finds its food.

The initiative, led by Ocean Conservancy alongside the Marine Conservation Institute and Environmental Defense Fund, asks countries to take four steps: commit to protecting the mesopelagic zone in national waters, support inclusion of mesopelagic protections in the UN General Assembly Sustainable Fisheries Resolution, invest in research to fill the enormous knowledge gaps, and adopt precautionary management before industrial exploitation begins.

That last point is urgent. With improving technology and rising demand for fish protein, industries are already exploring ways to harvest twilight zone animals for fish oil, pet food, and aquaculture feed. Norway, the world’s largest krill fishing nation, has been at the forefront of mesopelagic fisheries research, and several companies are developing technologies to catch species that have never been commercially fished.

“The twilight zone serves as a gateway between the ocean’s surface and the deep sea,” said Chris Dorsett, Vice President of Conservation at Ocean Conservancy. “Under threat from climate change, growing commercial interests, and other activities, this ocean layer urgently deserves a spotlight.”

In addition to Fiji and Panama formally joining, Portugal and Vanuatu expressed support for the challenge’s goals. Whether other major fishing nations follow will determine whether this initiative becomes meaningful policy or remains a conference announcement.

Norway is about to build the world’s first ship tunnel. It will carry vessels through a kilometre and a half of solid rock to avoid one of the most dangerous stretches of water in Europe.

The Stadhavet Sea, off the western coast of Norway, is one of the roughest patches of water on the planet. Storms sweep across it roughly 100 days a year. Waves arriving from multiple directions simultaneously can reach up to 30 metres. The Stadlandet Peninsula forces every vessel travelling the Norwegian coastal route, fishing boats, cargo ships, salmon-farm transports, ferries, and cruise ships, out around an exposed headland where the conditions can change in minutes.

For decades, the solution has been to wait. Vessels anchor and sit out the weather, sometimes for days at a time, delaying perishable seafood shipments and putting pressure on Norway’s rail network as the only alternative. Tore O. Sandvik, county mayor in Trøndelag, put the cost simply: salmon exported from his region to the continent cannot be left stuck at Stad in bad weather if it is meant to arrive fresh. The delays cost money. The route costs lives. Since the end of the Second World War, 33 people have died in maritime accidents in the Stadhavet Sea. The problem is old enough that Vikings used to drag their longships over the Dragseidet isthmus, a narrow pass across the peninsula, rather than risk the open water.

Norway’s answer is to go through the rock instead of around it. The Stad Ship Tunnel will run for 1.7 kilometres through the narrowest part of the peninsula, connecting the Moldefjord on one side with the Vanylvsfjord on the other. It will be 50 metres tall and 36 metres wide, large enough to accommodate the Hurtigruten coastal ferries and cruise ships. The estimated cost is NOK 8.6 billion, roughly $900 million.

The project has been discussed for decades and has lurched between approval and cancellation multiple times. In October 2025, Prime Minister Jonas Gahr Støre told Norwegian broadcaster NRK that the tunnel was simply too expensive. Supporters refused to give up. By early 2026, the Norwegian Coastal Administration had worked with three contractor groups to reduce costs. On 7 June, initial funding of NOK 150 million, roughly $16 million, was included in the revised national budget after a deal between Norway’s centre-left parties. Final parliamentary approval was expected by 19 June. Construction is planned to begin in early 2027, with a build time of approximately five years.

The engineering is remarkable. Workers will blast and excavate roughly eight million tonnes of rock to create the passage. The tunnel will include lead-in structures built out into the water on both sides to guide ships safely through the portal. Traffic will be one-directional, managed by a control system similar to those used in road tunnels.

“We are ready to initiate the processes needed to facilitate a construction start in the beginning of 2027,” said Kystverket Director General Einar Vik Arset.

There is no precedent for this anywhere in the world. Canal tunnels exist. Road tunnels under water exist. A tunnel carved through coastal rock specifically to allow ships to avoid a dangerous stretch of open sea does not. If completed, the Stad Ship Tunnel will be a piece of maritime infrastructure unlike anything else on the planet, built for the simplest of reasons: the sea outside is too rough, and people keep dying.

Quick Hits

The European Union has pledged €338.35 million for ocean conservation, sustainable fisheries, and maritime security at the Our Ocean Conference in Mombasa. Commissioner for fisheries and oceans Costas Kadis made the announcement on 17 June at the 11th Our Ocean Conference, the first to be held on African soil. The funding covers marine protected areas, pollution reduction, climate adaptation, deep-sea biodiversity research, and fisheries enforcement. The EU’s cumulative Our Ocean pledges now run into the billions, though tracking how much of previous commitments has been disbursed and implemented remains a challenge for watchdog organisations.

The UK has committed £13.9 million to ocean communities through the Blue Planet Fund, bringing total UK investment to over £86 million since 2021. Marine Minister Emma Hardy announced the funding at the same Mombasa conference, directing it through three programmes: PROBLUE, the World Bank’s blue economy trust fund (£6.7 million), the Ocean Risk and Resilience Action Alliance (£2.2 million), and the Global Plastic Action Partnership (£5 million). The money is going to specific projects: in São Tomé and Príncipe, PROBLUE funding is reducing flood risk for more than 800 households. In Vanga Bay, Kenya, ORRAA is developing one of the world’s first marine biodiversity credit schemes in the global south.

A mysterious sound detected near the Mariana Trench in 2014 took eight years to identify. It was a whale. In October 2014, autonomous underwater gliders operated by researchers at Oregon State University recorded an unusual noise in the deep western Pacific: a low, sonorous grunt followed by a squeaky, metallic echo that sounded more like a machine than an animal. Dubbed the Western Pacific Biotwang, the sound puzzled scientists because it did not match any known whale call and was detected year-round rather than only during breeding season. In 2024, a team finally confirmed the source: Bryde’s whales, a species of baleen whale found across tropical and warm temperate oceans. The story, resurfacing this week through Popular Mechanics, is a reminder that the ocean still produces sounds that take the better part of a decade to explain.

Hard Truth From The Sea

This week, the world’s governments gathered in Mombasa and pledged hundreds of millions of euros for ocean conservation. In Washington, it took ten senators and a public outcry to stop the same government from destroying $368 million worth of ocean instruments that were already in the water and already working. Fiji and Panama asked countries to protect a layer of ocean that most people have never heard of and that industries are already preparing to exploit. Norway committed nearly a billion dollars to tunnel through a mountain because the sea on the other side keeps killing people. Somewhere off the Kenyan coast, a fisherman is pulling in swordfish whose diet is 81 per cent twilight zone. He was not in the room in Mombasa when the pledge was made. Whether his livelihood survives the decade depends on decisions made by people who were.

Paid subscribers fund the reporting that tracks what is changing in the ocean and why. If you want accountability journalism on the systems we depend on and the institutions responsible for protecting them, please condisr upgarding to a paid subscription.

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See you next week.

- Luke

Last week, this newsletter covered a study that found the deep basins of the central Arctic Ocean almost empty of fish. Echo sounders returned near-silence. Trawl nets came up with almost nothing. The researchers called it a biological desert beneath the ice.

This week, a separate team has published a study that may explain why. Twenty years of data from the Fram Strait, the narrow passage between Svalbard and Greenland, where Arctic water drains into the North Atlantic, show that the chemical foundations of the Arctic food chain crossed a tipping point around 2009, and the researchers say it is unlikely to reverse.

That story leads a Deep Brief that also covers the discovery of more than 1,100 previously unknown marine species in a single year, and the first direct evidence that floating solar farms on the ocean generate significantly more electricity than solar panels on land. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

The Arctic Ocean has crossed a chemical tipping point.

The Arctic food chain depends on nitrate, a dissolved form of nitrogen that phytoplankton, the microscopic algae at the base of the food web, need to grow. Without nitrate, phytoplankton cannot photosynthesise in sufficient quantities to feed the zooplankton, fish, seabirds, and marine mammals above them. Nitrate in the Arctic is the fertiliser that makes everything else possible.

A study published this week in Communications Earth & Environment by an international team led by Professor Raja Ganeshram, at the University of Edinburgh’s School of GeoSciences, has found that nitrate concentrations in Arctic surface waters dropped sharply around 2009 and have not recovered. The shift, they argue, represents a regime change: the Arctic Ocean has moved from a system limited primarily by light, where the ice cover prevented photosynthesis by blocking sunlight, to a system limited by nutrients, where the ice has retreated, but the nitrate needed to fuel growth is being destroyed faster than it can be replenished.

The mechanism is a process called benthic denitrification. When sea ice retreats, sunlight reaches the shallow continental shelves that underlie nearly half of the Arctic Ocean. More light means more photosynthesis, which means more organic matter sinking to the seafloor. Microbes in the sediment consume that organic matter and, under the low-oxygen conditions that result, convert nitrate into nitrogen gas. Nitrogen gas is useless to most marine plankton. It escapes into the atmosphere and is, from the food web’s perspective, permanently lost.

The team analysed 20 years of oceanographic data collected from the Fram Strait, where polar surface water flows out of the Arctic and into the North Atlantic. They tracked nitrate concentrations and the ratio of silicon to nitrogen in those outflowing waters. After 2009, fixed nitrogen concentrations fell sharply while silicon-to-nitrogen ratios rose, a signature consistent with accelerated denitrification on the shelves. Combining these observations with modelled denitrification rates and tracking the paths that water takes across the Arctic shelves, the researchers identified the Chukchi Sea and the East Siberian shelf as the primary zones of nitrogen loss, removing approximately 12 teragrams of nitrogen annually, enough to offset a substantial portion of the nutrients entering the Arctic from the Pacific Ocean through the Bering Strait.

“The changes we report suggest that the Arctic Ocean ecosystem passed a tipping point around 2009,” Ganeshram said. “Once the sea-ice melts and the balance between nutrient supply and removal shifts, the original conditions can’t recover, even if ice were somehow restored.”

The consequences flow upward through the food chain. With less nitrate available, the Arctic may shift toward supporting smaller, less nutritious species of plankton. These smaller organisms transfer less energy to the fish, birds, and mammals that depend on them. The study also raises concerns about the Arctic’s capacity to absorb carbon dioxide: phytoplankton pull CO2 from the atmosphere during photosynthesis, and fewer phytoplankton means less carbon drawn down.

For readers who followed last week’s Deep Brief, this study completes a picture. The empty Arctic basins documented by the Norwegian Polar Institute were biologically vacant. The Edinburgh team’s work suggests that the chemical conditions needed to support life in those waters are actively deteriorating. The emptiness is not a baseline waiting to be filled as the ice retreats. It is a consequence of the retreat itself.

Scientists have identified more than 1,100 previously unknown marine species in a single year.

Ocean Census, a global initiative led by Japan’s Nippon Foundation and the UK-based ocean exploration institute Nekton, announced on 19 May that 1,121 previously unknown marine species were identified across 13 expeditions and 9 species discovery workshops in 2025. The figure represents a 54 per cent increase over the 728 new species recorded the previous year and involves more than 1,000 researchers working across 85 countries.

The discoveries came from depths as great as 6,575 metres and from some of the planet’s least explored marine environments. Among the species announced: a chimaera, commonly called a ghost shark, found at roughly 800 metres in the Coral Sea Marine Park off Queensland, Australia. Chimaeras are ancient cartilaginous fish that diverged from a common ancestor with sharks and rays nearly 400 million years ago, predating the dinosaurs. Their smooth, scaleless skin and reflective eyes give them an appearance that earned them their common name.

Near the South Sandwich Islands in the south Atlantic, at nearly 3,600 metres depth, researchers found a carnivorous sponge belonging to the genus Chondrocladia. Unlike typical sponges, which filter food passively from the water, this species traps small crustaceans using microscopic hooks on its surface, earning it the nickname “death ball” among the team that found it.

On volcanic seamounts in Japan, scientists discovered a bristle worm living inside the translucent chambers of a glass sponge, a structure built from crystalline silica, the same material used to make glass. The worm and the sponge share a symbiotic relationship: the worm gets shelter, and the sponge likely benefits from the worm’s feeding activity. In Timor-Leste, a ribbon worm just an inch long, marked by stripes of bright orange that signal chemical defences, was found in shallow water. The toxins that ribbon worms produce have been investigated as potential treatments for Alzheimer’s and schizophrenia.

“We spend billions searching for life on Mars or going to the dark side of the moon,” said Oliver Steeds, director of Ocean Census. “Discovering the majority of life on our own planet, in our own ocean, costs a fraction of that.”

The initiative is accelerating identification by recognising “discovered” as a formal scientific status that can be logged immediately into an open-access database once validated by an expert, before the longer formal description process is complete. This matters because many species may vanish before they are formally described, due to climate change, industrial pollution, and the growing prospect of deep-sea mining in regions where species have barely been catalogued.

Ocean Census has planned six new expeditions and five species discovery workshops for 2026.

Floating solar farms on the ocean generate 12 per cent more electricity than solar panels on land.

Researchers at Taiwan’s National Taipei University of Technology have published the first direct comparison between an offshore floating solar installation and a conventional land-based solar farm operating under similar conditions. The floating system generated roughly 12 per cent more electricity over its operational lifetime, according to the study, published on 19 May in the Journal of Renewable and Sustainable Energy.

The reason is temperature. Solar panels lose efficiency as they heat up. Panels mounted on land absorb heat from the ground and surrounding air. Panels floating on the ocean are cooled by the water beneath them and by stronger winds across the open surface. The temperature difference, typically two to three degrees Celsius lower at sea, is enough to produce a measurable gain in output.

The comparison was unusually clean. Taiwan Power Company had installed a 100-megawatt land-based solar farm in the Changbin Industrial Park. Nearby, Chenya Energy had deployed a 181-megawatt offshore floating photovoltaic system on 1.8 square kilometres of sheltered water within the same industrial zone. The proximity and similar conditions allowed the researchers to isolate the effect of the water surface on performance.

“What we found is that offshore floating solar systems can generate more electricity over their lifetime, about 12 per cent more than land-based systems under the same conditions,” said Ching-Feng Chen, one of the study’s authors. “Because of this higher energy output, they also achieve greater carbon emission reductions.”

Taiwan, roughly the size of the Netherlands, faces acute land constraints for renewable energy. Its energy sector accounts for more than half of national carbon emissions, and the island is currently 99 per cent dependent on imported natural gas, a vulnerability intensified by the ongoing disruption to shipping through the Strait of Hormuz. Offshore floating solar offers a pathway that does not compete with agriculture, does not require clearing land, and sits within reach of existing coastal grid infrastructure.

More than 1,100 floating solar installations now exist globally, predominantly on reservoirs and lakes in China and other densely populated Asian countries. The Taiwan study is significant because it compares offshore ocean deployment rather than freshwater, where conditions are calmer, less corrosive, and easier to maintain. Whether floating solar can withstand typhoons, salt corrosion, and biofouling over a 25-year operational life at sea remains the open engineering question. The 12 per cent advantage means nothing if the panels do not survive.

Quick Hits

In a fishing village on the coast of Mozambique, former seahorse poachers are now seahorse protectors. Fishermen in Mangalisse were being paid between 25 and 50 Mozambican meticais, roughly 30 to 60 pence, per dried seahorse by traffickers linked to the traditional Chinese medicine trade. The animals, which fishermen began calling “diamonds,” were being pulled from seagrass beds by the thousand. A community-led conservation initiative, supported by local lodge owner Mike van Hone and marine scientist Ilídio Cole, has turned the dynamic around: former collectors now guide research teams and patrol the seagrass beds. Globally, despite CITES Appendix II listing since 2002, the seahorse trade has shifted to a black market. Research from Project Seahorse at the University of British Columbia found that 95 per cent of dried seahorses in Hong Kong’s large market were being imported from countries that had export bans in place. Three seahorse species, giraffe, common, and thorny, are found in Mozambican waters.

India and Africa are being urged to deepen ocean cooperation across fisheries, renewable energy, and maritime security. A policy analysis by India’s Observer Research Foundation argues that combining India’s technical and industrial capacity with Africa’s marine resources and growing institutional frameworks could accelerate sustainable ocean development in both regions. The piece highlights Blue Bonds, joint action against illegal, unreported, and unregulated fishing, and shared investment in ocean renewable energy as priority areas. For a newsletter that covers ocean governance, the India-Africa maritime relationship is worth watching: together, the two regions control a substantial share of the Indian Ocean coastline and its fisheries.

This week’s Arctic tipping point study and last week’s empty Arctic basins study were published independently, a week apart, by different research teams. The Norwegian Polar Institute found almost no fish in the deep central Arctic. The University of Edinburgh found that the nutrient base those fish would need to survive is being chemically destroyed. Neither team cites the other. Together, they describe an ocean that is simultaneously losing its animals and the chemical conditions needed to support them. Readers who want both studies: the empty basins paper is in Communications Earth & Environment (Hop et al., 22 May 2026). The nitrate tipping point paper is in the same journal (Ganeshram et al., 28 May 2026).

Hard Truth From The Sea

In a single week, two independent studies described an Arctic Ocean that is losing both its life and the chemistry needed to sustain it. In another part of the ocean, scientists catalogued more than a thousand species nobody knew existed, many of them in waters that may not look the same in a decade. In Taiwan, engineers proved that the surface of the ocean can generate more clean energy than the land beside it. The ocean contains both the crisis and the means to address it. Which of them defines the next decade depends on decisions that have not yet been made.

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- Luke

In early March, I was added to a WhatsApp group of 300 scientists, journalists, and campaigners trying to work out what was killing the ocean in Papua New Guinea. I watched. I waited. I wanted to know what the government actually found, not what the campaign said they found. I got hold of the report. What it contains is not what the PNG government's public statements suggested. And when I put it to the palm oil corporation identified as a potential contributor, their answers raised more questions than they resolved.

On 11 December 2025, fish began dying in Larairu Lagoon, Kafkaf Village, on the east coast of New Ireland Province, Papua New Guinea. Within weeks, the die-offs had spread north along the Boluminski Highway coast. Community monitors documented 3,451 dead marine organisms across more than 15 species. Hundreds of residents reported skin burns and respiratory symptoms after contact with seawater. Families stopped fishing. Children stopped swimming.

Five months later, no government agency has confirmed what caused it.

The Guardian reported on the ongoing crisis this month. AFP, Mongabay, and Inside Climate News have covered the community dimension since March. What drew me was not that story. Other outlets were already covering it. It was a governance question nobody was pursuing: what did the PNG government actually find when it investigated, what does it admit it cannot determine, and what has it not yet done?

Ocean Rising has reviewed a preliminary report produced by the Conservation and Environment Protection Authority (CEPA) in April 2026, covering field investigations conducted in February. The findings are more troubling than the government’s public statements have suggested. Not a confirmed cause, but a clear picture of how far the investigation has to go.

What CEPA Found

The report was prepared by a small technical team that travelled to New Ireland, collected samples under difficult conditions, and produced an assessment they knew was insufficient before they filed it. That is not an indictment of the individuals involved. It is an indictment of what they were resourced to do.

The preliminary report documents clear environmental stress across multiple sites along the East Coast. Freshwater systems showed extreme turbidity, dangerously low dissolved oxygen, and nutrient levels far above acceptable thresholds. At Ladaim Creek, biological oxygen demand was recorded at 342 mg/L against a standard of 5 mg/L, indicating severe organic pollution and oxygen depletion. Ammonia levels at the same site exceeded safe limits by a factor of more than twenty. These findings are consistent with significant nutrient enrichment from land-based sources.

The ocean itself told a more complicated story. At Banatalis, near Kafkaf Village, seawater samples came back unusually acidic. Further along the coast, at sites near Laxunaru, the opposite was true: water so alkaline it was outside the normal range for any healthy marine environment. The explanation for that anomaly was natural gas vents in the reef system, which were documented and sampled by the investigation team. Seawater, in other words, was being chemically altered from below as well as from above. The report identifies a combination of factors: nutrient pollution from land, abnormal water chemistry from the vents, and possible bacterial contamination.

Fish tissue results, tested against Codex Alimentarius and US FDA standards, showed mercury and lead below detection limits across all nine samples. The report states clearly that heavy metal accumulation in fish tissue does not support heavy metals as the primary cause of the fish kills. For those who have been following the story, this significantly weakens the industrial mining contamination hypothesis that circulated from March.

The most likely explanation, according to CEPA’s own assessment, is a multi-stressor event driven primarily by degraded water quality: sediment loading, organic pollution, low dissolved oxygen, and possible vent-associated contamination, all exacerbated by exceptionally heavy rainfall in December 2025 and February 2026.

Oil palm agricultural runoff is specifically identified as a potential contributing factor. Poliamba Limited, the major oil palm operator in northern New Ireland, owns and manages estates along both the eastern and western coasts of the province. The operation was acquired by SD Guthrie Berhad, formerly Sime Darby Plantation, in 2015. What that means in practice, and what a separate university analysis found about the potential pathways between those plantations and the affected coastline, is examined below.

While the government’s investigation has stalled, community monitoring has continued. Independent scientists working with Ailan Awareness, the local marine conservation organisation that has led documentation efforts since December, conducted a further round of pH sampling across thirteen ocean sites in late April. Their readings, all below pH 9, raised questions about the reliability of some early government data, which had recorded alkalinity levels of pH 12 to 13. The community, in other words, is still doing science that the state has not completed.

What follows is the finding that no other outlet has reported, and the written record of a corporation that was asked specific questions and chose not to answer them.

Read more

On the journey from Svalbard toward the North Pole, the research vessel Kronprins Haakon carried echo sounders and trawl nets designed to detect and collect fish. The instruments scanned the water column from the surface to 500 metres below. The trawls were lowered repeatedly through the Nansen Basin and the Amundsen Basin, the vast, ice-covered waters of the central Arctic Ocean. The scientists expected to find at least some fish. They found almost none.

That study, published this week in Communications Earth & Environment, opens a Deep Brief that also covers the quiet disintegration of social life on coral reefs under ocean acidification, and a warning that the global network of instruments tracking what is happening in the ocean is being allowed to decay at the moment its data is needed most. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

Researchers sailed from Svalbard toward the North Pole searching for fish. They found an ocean that was almost completely empty.

In the late summers of 2022 and 2023, scientists from the Norwegian Polar Institute and the Fram Centre in Tromsø took the research vessel Kronprins Haakon on two expeditions from the continental shelf north of Svalbard out into the deep basins of the central Arctic Ocean. Along the way, they used calibrated echo sounders, which send sound waves into the water and detect the echoes that bounce back from fish and zooplankton, and a specially adapted trawl designed to work through openings in the sea ice. The goal was to build the first systematic picture of what fish live in these waters, how deep they go, and how many are there.

Near the continental slope, conditions were relatively productive. The researchers found capelin, polar cod, and other species associated with the nutrient-rich Atlantic water that flows into the Arctic from the south. Zooplankton, the tiny animals that form the base of the food web for fish, seabirds, and marine mammals, were present in reasonable densities.

Then they crossed over the slope and into the deep basins, where the seabed drops to more than 3,000 metres and the water column is dominated by cold, low-salinity Arctic water. The transition was stark.

“When we reached the cold, deep waters, there was nothing there. It was completely empty of fish,” said Haakon Hop, a senior researcher at the Norwegian Polar Institute and one of the study’s authors.

The echo sounders, which are sensitive enough to detect individual fish, returned almost no signal. The trawl catches confirmed it: beyond the continental slope, the mesopelagic zone, the layer of water between 200 and 1,000 metres deep that in other oceans teems with lanternfish, bristlemouths, and other small deep-water species, was essentially vacant.

The findings matter for two reasons. The first is ecological. The mesopelagic zone in the North Atlantic and sub-Arctic is relatively well-populated. Its absence in the central Arctic suggests that the deep Arctic Ocean may be one of the least productive bodies of water on the planet for fish, a biological desert beneath the ice that has largely escaped scientific attention because it is so hard to reach. The study, published this week in Communications Earth & Environment, is one of the first to survey these waters systematically using both acoustic and trawl methods.

The second reason is political. The Central Arctic Ocean Fisheries Agreement, signed by ten parties in 2018, placed a moratorium on commercial fishing in the high seas of the central Arctic for at least 16 years, largely because so little was known about what lived there. This study provides the first substantial baseline, and that baseline suggests there is almost nothing to catch. The moratorium, in other words, is not protecting a fishery from exploitation. It is protecting an emptiness from becoming one.

As Arctic sea ice continues to shrink, the question of whether commercial fish species will eventually move into these waters has been debated for years. Some projections suggested that warming could open new fishing grounds. This study suggests otherwise: the deep Arctic basins lack the conditions that support fish populations, and the biological pathways that would need to develop for colonisation to occur are complex and uncertain.

Ocean acidification is breaking apart the social structures that keep reef fish alive, and the fish themselves do not seem to notice.

For small fish on a coral reef, survival depends on being part of a group. Fish in shoals spot predators faster. They forage more efficiently. The simple mathematics of dilution, more bodies meaning any one fish is less likely to be the one that gets eaten, keeps individuals alive in ways that no amount of individual vigilance could replicate.

A new study from Adelaide University, published this week in the Journal of Animal Ecology, has found that ocean acidification is quietly dismantling these social structures by degrading the reefs that make them possible.

The research team, led by Dr Angus Mitchell and supervised by Professor Ivan Nagelkerken, worked at an unusual set of coral reefs in Japan that sit near volcanic CO2 seeps on the seafloor. These seeps naturally raise the acidity of the surrounding water to levels that closely match what scientists project for the broader ocean later this century under continued carbon emissions. Some nearby reefs experience present-day chemistry. Others are warmer. Some experience both elevated temperature and acidity together. The site functions as a living laboratory for studying what climate change does to reef ecosystems, without needing to wait decades for the conditions to arrive.

What the researchers found was not what they expected. The direct effects of warming and acidification on individual fish behaviour were, in most cases, minimal. Individual fish seemed to cope. They were not disoriented, not visibly stressed, not behaving abnormally in any obvious way.

The damage was structural. On reefs where acidification had reduced the complexity of the coral, the branching structures, caves, overhangs, and crevices that provide shelter and gathering points for fish, the fish formed smaller shoals. Smaller shoals meant less social protection. Fish in those groups were more cautious, spent more time hiding, and ventured into the open less frequently.

“In the real world, fish do not experience climate change in isolation,” Nagelkerken said. “They experience it as members of communities, shaped by the habitat around them and the other individuals they live alongside. Our results suggest that even when individual fish seem to be coping fine behaviourally under climate stress, the social structures supporting their behavioural expression can quietly fall apart.”

The mechanism is indirect, which is what makes it easy to miss. Acidification dissolves the calcium carbonate that corals use to build their skeletons. As reefs lose structural complexity, the physical spaces that support large aggregations of fish disappear. The fish do not die from the acidity. They die from the loneliness that follows the loss of their habitat.

The global network of instruments watching the ocean is under pressure at the moment it is needed most.

The Global Ocean Observing System, known as GOOS, is the closest thing the world has to a continuous monitoring system for the state of the ocean. It is built from a patchwork of complementary platforms, each designed to measure different parts of the ocean in different ways, and together they underpin the weather forecasts, climate projections, fisheries management systems, and disaster warnings that modern societies rely on.

Its most visible component is Argo, a fleet of roughly 4,000 autonomous robotic floats distributed across the world’s oceans. Every ten days, each float sinks to a depth of 2,000 metres, then rises slowly back to the surface, recording temperature and salinity as it ascends. When it reaches the surface, it transmits its data via satellite to ground stations, where it is made freely available to anyone within 24 hours. The programme has been running since 2000 and has fundamentally changed how scientists understand ocean heat content, salinity trends, and sea level change.

The challenge, as a new piece in The Conversation this week describes, is maintenance. Argo floats last four to five years before their batteries fail. The fleet must be continually replenished to prevent gaps from opening up across the oceans. The expansion to OneArgo, which would add biogeochemical sensors, deep-diving floats capable of reaching 6,000 metres, and instruments designed for marginal seas and polar waters, requires sustained international funding that is not yet secured.

New Zealand provides a case study in what smaller countries can contribute: the research vessel Kaharoa has deployed more than 1,100 Argo floats for international partners across the Pacific and Southern Oceans since 2004. Elephant seals fitted with sensors collect data beneath polar sea ice in regions no other instrument can easily reach.

The piece, written by scientists involved in the programme, argues that national ocean observing strategies need to be developed, that ocean observations should be embedded in climate adaptation planning, and that governments should recognise ocean data as critical infrastructure.

The argument has particular force this week. Deep Brief #37’s good news edition covered the Rothera Time Series in Antarctica, 28 years of weekly water sampling sustained by scientists who kept going out in a boat regardless of whether anyone was paying attention. The GOOS story is the global version of the same principle: continuous measurement is the infrastructure that everything else depends on, and it is the first thing to be cut when budgets tighten. The instruments do not lobby for themselves. If governments do not fund them, the data stops, and nobody notices until the next forecast goes wrong.

Quick Hits

Ninety-eight per cent of Europeans say protecting marine life is important, but only 14 per cent identify underwater noise as a threat to the ocean. A survey conducted by Ipsos for the International Fund for Animal Welfare across France, Germany, the Netherlands, Spain, and Sweden in March 2026 found that once the impact of shipping noise on marine mammals was explained, 89 per cent of respondents said the issue should be addressed urgently, and more than 80 per cent supported practical measures including mandatory ship speed reductions. IFAW is calling on the EU to integrate ship speed limits into the revised Marine Strategy Framework Directive and the upcoming European Ocean Act. The gap between the 98 per cent who care and the 14 per cent who know about noise is itself the finding: the problem is not public indifference, it is public invisibility.

The European Commission has launched a public consultation on the European Ocean Act, with responses open until 16 July 2026. The Ocean Act, a key legislative proposal under the European Ocean Pact adopted in June 2025, aims to consolidate all EU economic, climate, environmental, and social targets for the ocean into a single legal framework. It would modernise maritime spatial planning, create a legal basis for the EU’s OceanEye observation initiative, and align with the ongoing revision of the Marine Strategy Framework Directive. The Commission plans to adopt the legislative proposal by the end of 2026. Whether it delivers meaningful enforcement mechanisms or becomes another layer of aspiration without teeth remains to be seen.

A great white shark has been caught in the western Mediterranean for the first time in years, and scientists are asking whether warming seas could push the species further north. A juvenile great white, just over two metres long and weighing between 80 and 90 kilograms, was captured in Spanish Mediterranean waters in April 2023. The finding, published this year in Acta Ichthyologica et Piscatoria, contributes to a slow accumulation of evidence that sub-tropical species are expanding their range as ocean temperatures rise. Great whites already frequent the Bay of Biscay. Whether they will eventually appear in Irish or British waters is speculative, but the direction of travel, for this species and many others, is northward.

Hard Truth From The Sea

Scientists sailed into the central Arctic and found an ocean almost completely empty of fish. On coral reefs in Japan, fish are forming smaller groups because the structures they gather around are dissolving. The global network of instruments that tracks what is happening in the ocean is running on batteries that last five years, and the funding to replace them is not guaranteed. Each of these stories describes a different kind of absence: the absence of life where life was expected, the absence of shelter where shelter once existed, the absence of commitment to the measurement systems that would tell us how much we are losing. The ocean is full of things that are quietly disappearing. The question is whether we are watching closely enough to notice before they are gone.

Paid subscribers fund the reporting that tracks what is changing in the ocean and why. If you want accountability journalism on the systems we depend on and the institutions responsible for protecting them, please consider upgrading your subscription.

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See you next week.

- Luke

Arsenal won the English Premier League last night, and they weren’t even playing.

They were watching Manchester City draw 1-1 at Bournemouth, and when the whistle went, the title was theirs. Twenty-two years of waiting, confirmed by someone else’s result on a Tuesday night, hundreds of miles from anyone in a red and white shirt.

I’ve been an Arsenal fan for over thirty-five years. Twenty-two of those have been spent waiting for last night. The High Seas Treaty took the same twenty-two years to come into force this January.

So forgive me for noticing it, but it’s also a perfect illustration of how the work I cover actually gets done.

Because the climactic moment isn’t where the work happens. The work happened months earlier, in games that didn’t trend, on nights when the title felt a hundred points away. By the time the trophy arrived, it had already been won.

I keep thinking about this because most of the ocean conservation stories I follow work the same way, and most of us are still waiting for the wrong moment.

The Long Wait for Success

On 17 January 2026, the High Seas Treaty entered into force. The agreement, formally the BBNJ Agreement, provides the first legal framework to protect biodiversity in the two-thirds of the ocean that lies beyond any country’s jurisdiction. It is the biggest expansion of ocean governance in a generation.

Almost nothing happened on the day it became law.

Morocco had ratified the previous September, the sixtieth country to do so, which, under Article 68, triggered a 120-day countdown. The countdown expired on a Saturday. There was no ceremony; the treaty just became binding on the countries that had ratified it.

UN-facilitated talks began in June 2004 with an informal consultative meeting. An Ad Hoc Working Group then spent nine years, between 2006 and 2015, just studying whether a treaty was feasible. A Preparatory Committee took another two years to draft elements of the text. The Intergovernmental Conference that finally negotiated the agreement convened in 2018 and met five times before reaching consensus in June 2023. Then came the slow business of getting sixty countries to ratify, which took another two and a half years.

Twenty-two years from the first talks to entry into force. The same gap that just separated Arsenal from their last title. Nine of those years were spent deciding whether to start.

The story that gets told about BBNJ is the one from June 2023, when delegates applauded the adopted text and the headlines called it historic. That moment got the photographs. But the treaty wasn’t won in June 2023. It was won in 2004, when an informal meeting put the question on the table. It was won in the rooms between 2006 and 2015 where a working group failed to draft anything binding and somebody decided to keep meeting anyway. It was won by Palau being the first to ratify in January 2024, and by every country that ratified in the eighteen months after. By the time the threshold was crossed, the win had already happened.

When BBNJ enters its first Conference of Parties later this year, that meeting will be reported as the moment ocean protection became real. It won’t be. The moment will have happened years earlier, in rooms that nobody photographed.

The Other Tuesday Night Games

Once you start looking, BBNJ isn’t even the exception. It’s the template.

Across ocean governance, dozens of processes are running concurrently, each on its own slow grind, each invisible to almost everyone except the people inside it.

In Geneva last August, the sixth round of formal negotiations for a global plastics treaty broke down. Delegates from 185 countries worked past the deadline into the early hours. The chair resigned. Headlines called it a failure, a missed opportunity, no solution in sight. In February 2026, a new chair was elected. The next round is expected late this year or early next. If you’re sitting inside year three of what is probably a twenty-year negotiation, this looks like a collapse. In twenty years, it will probably look like the unglamorous middle of a process that worked.

In Kingston, in March, the International Seabed Authority concluded another round of negotiations on whether to allow commercial deep-sea mining. Forty nations now support a moratorium or precautionary pause, up from a handful five years ago. No Mining Code was adopted. No mining was approved. The Metals Company, having tried to bypass the ISA entirely by applying directly to the US government under a Trump executive order, is now under investigation by the very body it was trying to sidestep.

The whaling moratorium, agreed in 1982 after years of failed votes at the IWC and thirty-six years after the Commission was founded to manage rather than restrict the industry, has saved most great whale species from the brink. It also hasn’t held cleanly. Japan left the IWC in 2019, added fin whales to its commercial quota in 2024, and set 2026 catch limits at over 400 animals. The work of defending the moratorium is now older than the moratorium itself.

None of these processes will produce a climactic moment that makes the news. Plastics will not be “solved” by a treaty signing. A single vote will not stop deep-sea mining. The whaling moratorium will not be celebrated by anyone outside the room when it survives another challenge. Between them, these processes, and dozens more like them, protect what’s left of the ocean.

The Honest Version of the Lesson

Arsenal finished second in the Premier League in 2022-23. Second again in 2023-24. Second again in 2024-25. Three consecutive runner-up finishes, each one accompanied by the same well-meaning commentary about how this group of players didn't quite have what it took. By April this year, three-quarters through what was looking like a fourth such season, Arsenal lost 2-1 at Manchester City. The title race appeared to be slipping away. At the final whistle, Declan Rice was crouched on the pitch when he looked up at his captain, Martin Ødegaard, who appeared to have lost belief. Rice shook his head and said: "It's not done."

It would have been entirely reasonable, in that moment, to conclude that it was done. The title was out of their hands for the first time since October. The collapse looked plausible.

Arsenal won their next four league games without conceding a goal.

The optimistic story about persistence is that if you keep going, you’ll eventually win. It’s not quite true. The plastics treaty might never be agreed. The deep-sea mining moratorium movement might be overrun by a few states acting unilaterally. The whaling moratorium might be undermined further if more nations follow Japan out of the IWC. Sometimes you keep going, and you still lose.

Keep going wins, because quitting guarantees losing. The work is worth doing whether or not it succeeds. The alternative is to decide that the moment hasn’t arrived, so the moment must not be coming, so the work must not be working. That logic guarantees the loss. Every campaign that ever produced a result was built by people who could have reasonably concluded, ten years in, that it wasn’t going to work.

Most of the people doing this work right now will not be in the room when the result comes. The lawyers drafting the BBNJ text in 2009 did not all live to see Morocco ratify. The IWC delegates who voted in 1982 were mostly not in the rooms in 1972 where the idea first failed. The people sitting in Kingston this March, arguing for a moratorium on deep-sea mining, will not all be there when the question is finally settled.

That, I think, is the actual deal. You do the unglamorous work, year after year, in rooms nobody is reporting from, against opposition that is better-resourced and more patient than you expected. You finish second for as long as it takes. And one Tuesday night, somebody else’s result confirms what your work has already decided.

Years ago, in the early days of manager Mikel Arteta’s tenure, a blacked-out silhouette of the Premier League trophy was installed at Arsenal’s training ground. The players walked past it every morning. The intention was that one day, when Arsenal were champions again, the silhouette would be lit up.

Most of the people doing the work that will protect what’s left of the ocean are walking past their own version of that silhouette right now. The lights aren’t on yet. They might never come on.

The work happens anyway.

Somewhere off the Ningaloo coast of Western Australia, in a submarine canyon that drops to more than four and a half kilometres, a giant squid shed a few cells into the surrounding seawater. It may have brushed against a rock, expelled waste, or simply moved through the water column. The cells drifted. Months later, a team of scientists on the research vessel Falkor filtered a sample of that water, extracted the DNA it contained, and matched it to Architeuthis dux, the largest invertebrate on the planet. Nobody saw the animal. Nobody needed to. Its genetic signature was enough.

That story leads this week’s Deep Brief, alongside a new gasfield approval ten kilometres from the Twelve Apostles on Australia’s Great Ocean Road, and a reflection on what David Attenborough, who turned 100 yesterday, showed the world about the ocean and what governments have done with the knowledge since. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

A giant squid’s DNA has been found in Western Australian waters for the first time in over 25 years. It was one of 226 species detected by filtering seawater.

Scientists from Curtin University, the University of Western Australia, and the Western Australian Museum collected more than 1,000 water samples from the deep Cape Range and Cloates submarine canyons off the Ningaloo coast, roughly 1,200 kilometres north of Perth, at depths reaching 4,510 metres. They were looking for environmental DNA, the genetic material that every living animal sheds invisibly into the water around it through skin cells, waste, mucus, and reproductive material.

From those samples, the team identified 226 species across 11 major animal groups. Among them: the giant squid (Architeuthis dux), detected in six separate samples from both canyons, the first record of the species in Western Australian waters in more than a quarter of a century and the northernmost confirmed detection of giant squid in the entire eastern Indian Ocean.

Giant squid can grow longer than a school bus, typically between 10 and 13 metres, and weigh up to 275 kilograms. Their eyes, at up to 30 centimetres in diameter, are the largest of any animal on Earth. Despite their size and near-global distribution, they are almost never seen alive. Fewer than a dozen have been filmed in their natural habitat in the deep ocean.

The survey also detected Cuvier’s beaked whales, the deepest-diving mammals known to science, pygmy sperm whales, sleeper sharks, the faceless cusk eel, and the slender snaggletooth. Dozens of species had never been recorded in Western Australian waters before. Some of the DNA sequences did not match anything in existing genetic databases, meaning they may belong to species that have not yet been formally described.

The study, published this week in the journal Environmental DNA, was conducted aboard the Schmidt Ocean Institute’s research vessel Falkor. Lead author Georgia Nester, who carried out the research as part of her PhD at Curtin University and is now at the University of Western Australia, described the results as transformative. “With eDNA, a single water sample can tell us about hundreds of species at once,” she said. “That means we can dramatically expand our understanding of deep-water environments in a way that simply hasn’t been possible before.”

The implications stretch beyond Western Australia. Environmental DNA surveys are fast, non-invasive, and scalable. They do not require scientists to see, capture, or disturb any animal. A single filtered water sample from a deep-sea canyon can reveal the presence of species that traditional surveys using nets, cameras, or submersibles might never detect. For regions of the ocean that are too deep, too remote, or too expensive to survey by conventional means, which is most of the deep ocean, eDNA may be the only realistic way to establish what lives there.

“Deep-sea ecosystems are vast, remote and expensive to study, yet they face growing pressure from climate change, fishing and resource extraction,” said Zoe Richards, a co-author and associate professor at Curtin University. “You can’t protect what you don’t know exists.”

Australia has approved a new gasfield ten kilometres from the Twelve Apostles. The government that greenlit it has a 95 per cent renewable energy target.

The Victorian and Australian federal governments, both Labor, announced on Thursday that they had granted a production licence for Amplitude Energy’s Annie gasfield in the Otway Basin, off the coast of Victoria. The site sits roughly nine kilometres offshore from Peterborough and Port Campbell, on the Great Ocean Road, about twelve kilometres west of the Twelve Apostles, one of Australia’s most visited natural landmarks and a designated marine national park.

Federal Resources Minister Madeleine King said the project would supply gas exclusively to the domestic market, easing the risk of potential shortfalls on Australia’s east coast. Amplitude Energy estimates the field will supply about four per cent of east coast gas demand for five years. Gas from the Annie field, in water depths of roughly 55 metres, will be processed at the existing Athena plant. Production is expected by 2028.

The approval is the second major gas project Labor has authorised this term, following the 2022 Victorian election in which then-Premier Daniel Andrews campaigned heavily on reviving the State Electricity Commission and accelerating the transition to renewables. Victoria has a legislated target of 95 per cent renewable energy by 2035.

For environmentalists, the approval undercuts the government’s own climate ambitions. Approving new fossil fuel extraction while pursuing aggressive renewable energy targets sends contradictory signals. The argument from government is that the transition requires bridging fuel to maintain energy security during the shift from coal and gas to renewables, and that domestic gas supply reduces reliance on more carbon-intensive imports.

The counter-argument, made by conservation and climate groups, is that new gas infrastructure locks in emissions for the life of the asset and that alternative sources of energy security, including battery storage, demand management, and accelerated renewable build-out, are available and increasingly cost-competitive. The presence of the gasfield near a marine national park adds an environmental dimension beyond carbon: the risk of operational discharges, spills, and acoustic disturbance to a stretch of coastline that is nationally significant for both tourism and marine biodiversity.

This story will be familiar to readers of this newsletter. In Australia, as in the UK, the gap between what governments promise on climate and what they approve in practice continues to widen. Whether the Annie gasfield turns out to be a necessary bridge or an unnecessary lock-in depends on how fast the renewable transition actually moves, and on whether the government that approved it is held to its own targets.

David Attenborough turned 100 yesterday. The ocean he showed the world is in worse shape than when he started filming it.

David Attenborough was born on 8 May 1926. Yesterday, on his 100th birthday, he remains the most recognisable voice in nature broadcasting and one of the most trusted figures in public life anywhere in the world. His career spans the transition from black-and-white studio television to 4K underwater cinematography. His programmes, from The Blue Planet in 2001 to Ocean in 2025, have brought the deep sea, coral reefs, open ocean ecosystems, and the creatures that inhabit them into hundreds of millions of living rooms.

What Attenborough did, more than any other broadcaster, was show people the ocean as a living system rather than a backdrop. The Blue Planet and its sequel Blue Planet II revealed the complexity of marine ecosystems in ways that shifted public attitudes. Blue Planet II in particular is widely credited with sparking a global movement against single-use plastics, leading several countries to introduce bans or restrictions. His 2025 feature-length documentary Ocean, now streaming on Disney+, went further, including footage of bottom trawlers ploughing up the seabed off the UK coast.

The New Statesman, in a piece published to mark his birthday, argues that governments must honour his legacy with action rather than warm words and commemorative stamps. The piece, written by Greenpeace’s Will McCallum, calls on the UK to use the Global Ocean Treaty to protect areas of the Atlantic, to ensure its marine protected areas are genuinely managed, and to implement a full ban on bottom trawling.

The timing is pointed. Last week’s Deep Brief covered the UK Marine Strategy report, which found that 13 of 15 indicators of ocean health are failing, uncertain, or declining, despite 377 marine protected areas covering 38 per cent of UK seas. Attenborough’s legacy includes both what he showed us and the uncomfortable question of whether knowing about the ocean’s wonders and its decline has produced commensurate action. The evidence, on his 100th birthday, suggests it has not.

Attenborough himself has shifted from traditional broadcaster to something closer to a campaigner in recent years, using his authority to advocate for systemic change. His witness statement film A Life on Our Planet (2020) laid out both the problem and his proposed solutions. Whether those solutions are adopted is no longer a question for Attenborough. It is a question for the people who grew up watching his programmes and now hold the positions of power that could deliver them.

Quick Hits

The deepest hydrothermal vents on Earth sit nearly five kilometres below the Caribbean Sea, and they are teeming with life. The Beebe Vent Field, discovered in 2010 by the crew of the RRS James Cook in the Cayman Trough, lies at 4,968 metres depth. Water erupting from its black smoker chimneys reaches 401°C but does not boil because the pressure at that depth is roughly 500 times atmospheric pressure. Despite the extreme heat and total darkness, the vents support thriving communities of shrimp, snails, and microbial life that derive their energy from chemical reactions rather than sunlight, a process called chemosynthesis. Discover Wildlife published a detailed profile of the Beebe field this week, and it is worth reading for anyone interested in the conditions under which life can persist.

Researchers in China sank a cow carcass to 1,629 metres in the South China Sea to mimic a whale fall, and eight Pacific sleeper sharks showed up. The study, published in Ocean-Land-Atmosphere Research in June 2025 and resurfacing in coverage this week, documented the first recorded appearance of Pacific sleeper sharks in the South China Sea, significantly expanding the known range of a species typically associated with the cold deep waters of the Bering Sea, the Gulf of Alaska, and Baja California. The researchers at Sun Yat-sen University observed larger sharks tearing aggressively at the carcass while smaller individuals circled and waited, suggesting a feeding hierarchy. Every shark observed was female, raising the possibility that the South China Sea may serve as a nursery ground for the species.

Scientists in Halifax are testing whether adding alkaline minerals to seawater can help the ocean absorb more carbon dioxide. Planetary Technologies is running one of the world’s first coastal ocean alkalinity enhancement projects in Halifax Harbour, Canada, introducing alkaline minerals through the cooling water discharge pipe of a natural gas power plant. Researchers from Duke University deployed instruments in August 2025 to measure how the surrounding ecosystem is responding. Ocean alkalinity enhancement works by reducing seawater acidity, which increases its capacity to absorb and store atmospheric CO2 for centuries. The approach is gaining attention as a potential complement to emissions reductions, though questions about ecological impact, monitoring, and scale remain unresolved.

Hard Truth From The Sea

David Attenborough turned 100 yesterday. He spent a career showing people what lives in the ocean, and in doing so made it harder for anyone to claim they did not know. That knowledge has not translated into proportionate action. The UK still allows bottom trawling in its marine protected areas. Australia approves new gasfields within sight of its most famous coastline. And in a canyon off Western Australia, a giant squid leaves its DNA in the water for scientists to find, in a region so unexplored that more than 200 species had never been recorded there before. Attenborough’s gift was wonder. The question his centenary poses is whether wonder, on its own, was ever enough.

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A study published last week in Communications Earth & Environment makes a measurement that hasn’t been made before. Over the past two decades, a layer of warm water deep beneath the Southern Ocean has been shifting south, towards the Antarctic continent, at an average rate of about 1.26 kilometres per year. Compounded over twenty years, that comes to roughly 25 kilometres of poleward redistribution, a meaningful fraction of the distance between the typical core of this warm layer and the Antarctic continental shelf.

The water is called Circumpolar Deep Water. It sits between roughly 200 and 2,000 metres down, wrapping around the continent, and it carries the heat that melts Antarctic ice shelves from below.

Those shelves matter because they hold back the much larger ice sheet behind them. The ice that sits on the Antarctic continent, if it eventually entered the ocean, would raise global sea level by about 58 metres.

The new study, led by Joshua Lanham at the University of Cambridge with colleagues at Scripps Institution of Oceanography and UCLA, uses two independent datasets to show that the warm layer is expanding nearer the continent and contracting further north. Both methods reach the same conclusion. Earlier observational work had already detected poleward shifts in specific regions of East Antarctica. What is new here is a circumpolar picture, built from a methodology that bridges two very different kinds of ocean data.

Why warm water at depth matters

Circumpolar Deep Water is warm because of where it came from. It originated in the North Atlantic and Pacific, sank with more heat than the abyssal water around it, and travelled south on timescales of decades to centuries, retaining much of that heat as it went. By the time it reaches the Southern Ocean it is no longer warm in any everyday sense, typically a degree or two above freezing, but compared with the near-freezing surface waters around Antarctica and the ice it might encounter, the temperature difference is substantial. When it reaches the underside of an ice shelf, that small difference is enough to drive significant melting.

The reason warm water can sit beneath cold water in this part of the ocean is salinity. Cold water near Antarctica is freshened by sea ice melt and precipitation, while the deeper layer carries higher salt content from its origins thousands of kilometres away. Salt makes water heavier. The deeper layer is denser despite being warmer, and stratification holds it in place.

Ice shelves are floating extensions of the ice sheet that sits on the Antarctic continent. They do not themselves contribute to sea level when they melt, because they are already in the water. What they do is buttress the glaciers and ice behind them. When ice shelves thin or collapse, the inland ice flows faster into the sea. Basal melt, driven by ocean heat reaching the underside of these shelves, is the dominant control on ice shelf mass loss. Surface melt matters far less than what is going on underneath.

What the study did

The first dataset is a network of repeat ship surveys called GO-SHIP, in which research vessels sail the same lines across the world’s oceans every decade or so, lowering instruments that measure temperature, salinity, oxygen, and a handful of other chemical tracers from surface to seabed. These measurements are precise but the lines are widely spaced and visited infrequently. Comparing surveys from 2005-2010 against surveys from 2015 onwards, the team found that warm Circumpolar Deep Water had increased in concentration nearer the Antarctic continent and decreased further north.

The second dataset is the Argo float programme: nearly four thousand robotic floats drifting through the world’s oceans, surfacing every ten days to transmit profiles of temperature and salinity in the upper 2,000 metres. The Argo data offers monthly resolution and global coverage, which the ship surveys cannot. The floats only measure two variables, however, which is not enough to identify water masses using the standard chemical-fingerprint method that ship surveys allow.

The team’s solution was to train a machine learning model on the rich GO-SHIP data, where water masses can be identified directly from the chemistry, and then apply that model to the sparser Argo measurements to fill in the spatial and temporal gaps. When tested against ship measurements it had not been trained on, the model performed well in nearly every region of the Southern Ocean. Applied to twenty years of Argo data, it produced the same poleward shift the ship surveys had shown, with finer detail. The pattern is the dominant feature of the twenty-year record once seasonal variation is removed, which is what makes the paper persuasive.

What the paper does and does not show

The study demonstrates that warm deep water has shifted closer to the Antarctic continent. It does not directly measure how much additional heat is reaching the ice shelves themselves. The Argo float data used in the analysis stops at 65°S, the latitude band immediately north of the Antarctic shelf, and it cannot sample the near-shelf waters where ice melt actually happens.

What the study does show is that within the band of ocean immediately north of the continent, ocean heat content in the warm-water layer has been accumulating at a rate equivalent to a continuous 2.81 terawatts of energy. That is a substantial amount of heat building up close to where the ice meets the sea. Whether and how much of it is currently crossing onto the shelves depends on local processes the study cannot resolve at continental scale. Winds, eddies, bathymetry, and the behaviour of dense shelf water that can act as a barrier all shape what happens at the final stretch.

The mechanism behind the migration is also unsettled. The paper presents two broad candidates. The first is that dense, cold water that normally sinks near the Antarctic coast (Antarctic Bottom Water) has been weakening, a trend already observed in independent studies, and as it contracts the warm layer migrates south to fill the space. The second is that wind-driven changes in the Southern Ocean, including strengthening westerly winds and a poleward shift in the wind belt itself, have moved the position of the Antarctic Circumpolar Current and the upwelling pathways of warm water along with it. The two mechanisms are not mutually exclusive, and the paper does not pick between them.

Why this is significant

Until now, scientists have relied largely on climate models to project what would happen as the Southern Ocean warmed. The models suggested that warm deep water would shift poleward and that ice shelf melt would accelerate as a result. Observational evidence for the shift has been piecemeal and regional.

This study is the first to show, from observations rather than projections, that the predicted shift is already underway across the entire Southern Ocean. As Lanham put it in the Cambridge press release, this is no longer a possible future scenario, it is something that is happening now.

The timescales over which the world is making decisions about climate, ice loss, and sea level rise rely on assumptions about what is happening to Antarctic ice. If the heat delivery system is shifting in the way this study describes, the question is not whether basal melting accelerates but how quickly. The paper does not answer that question, but it does establish that the question has stopped being hypothetical.

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The UK protects 38 per cent of its seas by law. It has 377 marine protected areas. It committed, years ago, to achieving what the government calls “good environmental status” across 15 measures of ocean health. This week, the Department for Environment, Food and Rural Affairs published its latest assessment. Of those 15 measures, two are meeting the standard. The other 13 are failing, uncertain, or getting worse. The target date for achieving the standard was 2020.

That story opens this week’s Deep Brief, alongside a new study suggesting the Atlantic’s great overturning circulation could weaken by half this century, far more than previous models predicted, and two research expeditions that sent a robot and a net system into the deep Atlantic to track how the largest daily animal migration on Earth moves carbon out of the atmosphere.

Deep Dives

The UK protects a third of its seas. Its own government report says the ocean is still in decline.

The UK Marine Strategy report, published by Defra in April 2026, assesses the health of UK seas against 15 indicators covering everything from fish populations and seabed habitats to marine litter, underwater noise, and contamination of seafood. The benchmark is good environmental status, a standard the UK committed to reaching by 2020 under the UK Marine Strategy Regulations, which originally derived from the EU Marine Strategy Framework Directive.

Only two of the 15 indicators clearly meet that standard. Fish communities are deteriorating. Seabed habitats continue to decline. Marine bird populations are falling. Contamination levels in some species remain above safe thresholds. The assessment notes that while climate-related pressures, including rising sea surface temperatures, more frequent marine heatwaves, ocean acidification, and oxygen depletion, are evident across many indicators, most have not yet identified climate change as the primary driver of their current status. The primary drivers, for now, remain overfishing, habitat damage from bottom-contact fishing gear, pollution, and nutrient runoff.

The gap between the UK’s marine protection on paper and its ocean health in practice is the central tension. The country now has 377 marine protected areas covering 38 per cent of its waters, a figure that comfortably exceeds the 30 per cent target that governments agreed to at the UN Biodiversity Conference in 2022. The problem, as conservation groups have argued for years, is that designation without meaningful management achieves very little.

“Continued massive overfishing, refusal to ban bottom trawling even in supposedly protected areas and non-existent monitoring or enforcement means it’s hardly surprising that the seas are in such a bad state,” said Jonny Hughes, Fisheries Policy Lead at the Blue Marine Foundation.

Oceana UK echoed the criticism. Izzy Ross, Oceana’s fisheries campaigner, said MPAs had to be more than “lines on a map” and pointed out that the government’s own deadline for achieving good environmental status had passed five years ago.

The report itself acknowledges that “more remains to be done” and notes “encouraging signs of recovery” in some areas, though it does not specify which indicators are improving or by how much. Defra has not announced any new enforcement measures or management changes in response to the findings.

For readers of this newsletter, the UK report card is a case study in a pattern visible across many maritime nations: governments count protected areas as a measure of progress while the ecosystems inside those areas continue to decline. Protection that does not change what happens in the water is not protection. It is cartography.

A new study says the AMOC could weaken by half this century, far more than previous models predicted.

Three weeks ago, Deep Brief #36 covered research showing that the Atlantic Meridional Overturning Circulation (the word meridional just means running north to south) had weakened by roughly 10 per cent between 2004 and 2023, based on mooring array data from four locations across the Atlantic. That study, led by Qianjiang Xing at the University of Miami and published in Science Advances, provided the strongest direct observational evidence so far that the system is slowing.

This week, a separate team has published a study in the same journal that asks a different question: how much worse could it get?

The answer, according to a team led by Valentin Portmann at the Inria Centre de recherche Bordeaux Sud-Ouest in France, is significantly worse than most climate models have predicted. Their study projects that the AMOC could weaken by 51 per cent by 2100 under medium to high emissions scenarios. That figure is around 60 per cent higher than the average projection produced by standard climate models.

The reason for the discrepancy is methodological. Portmann’s team identified two systematic errors running through many of the most widely used climate models: they simulate the South Atlantic as not salty enough and the North Atlantic as too cold. Both biases cause the models to underestimate a key process in which dense, salty water sinks at the northern end of the system and drives the entire circulation. After correcting for both biases using a statistical technique called ridge-regularised linear regression, the projected weakening rose substantially and the uncertainty around the estimate dropped.

The study tested four emissions scenarios. Three of them, ranging from medium to very high, converged on a similar outcome of roughly 50 per cent weakening, suggesting that beyond a certain threshold of emissions, much of the damage may already be locked in by the heat the ocean has already absorbed. The most optimistic scenario, representing aggressive and sustained emissions reductions, produced a weakening of only around 20 per cent.

A 51 per cent weakening would not be a collapse, and the study’s authors are careful to distinguish the two. The Intergovernmental Panel on Climate Change has said it has medium confidence that a full AMOC collapse will not occur before 2100. What each additional weakening does, however, is push the system closer to a tipping point, the threshold beyond which the circulation reorganises into a fundamentally weaker state that could take thousands of years to reverse. Where that threshold sits is unknown.

The consequences of the kind of weakening Portmann’s study projects would include colder, harsher winters across Northern Europe, a southward shift of tropical rain belts threatening monsoon systems that hundreds of millions of people in West Africa and South Asia depend on for food, and accelerated sea level rise along the US East Coast. A 2025 study published in Geophysical Research Letters found that in a full collapse scenario, cold extremes could reach minus 20°C in London and minus 48°C in Oslo, even with greenhouse-driven global warming pushing temperatures up everywhere else.

“We have put a lot of heat into the ocean that is going to cool down over centuries,” Portmann told BBC Science Focus. “But on the other hand, you can say that before the tipping point, we can avoid a severe weakening with a strong reduction of CO2.”

Two research expeditions sent a robot and a deep-sea net system into the Atlantic to track how animals move carbon out of the atmosphere.

Every night, across the entire ocean, trillions of small animals rise from the deep toward the surface to feed. Before dawn, they descend again, carrying the carbon they consumed at the surface back down to depths of 200 to 1,000 metres, where it can be stored for decades to centuries. This daily cycle, called diel vertical migration (the word diel means happening over a 24-hour period), is the largest synchronised movement of biomass on the planet and a significant but poorly measured component of the ocean’s ability to absorb carbon dioxide from the atmosphere.

Two back-to-back expeditions aboard the Schmidt Ocean Institute’s research vessel Falkor (too), working in the Southwest Atlantic off the coast of Brazil and Uruguay, have been investigating the mechanics of this process and the broader question of how carbon moves through the ocean’s interior.

The first expedition, called “Animals as Living Bioreactors” and led by Anitra Ingalls of the University of Washington, focused on the animals themselves. The team used the remotely operated vehicle SuBastian and a system of deep-sea nets called MOCNESS (an acronym for Multiple Opening and Closing Net and Environmental Sensing System, essentially a stack of nets that can be opened and closed at specific depths to sample different layers of the water column) to collect animals at various stages of their nightly migration. Among the questions the researchers are pursuing is whether the gut microbiomes of migrating animals are transforming the food they eat at the surface into essential nutrients, including vitamin B12, for organisms living in deeper waters. Many of the animals collected are new to the South Atlantic record, and some are likely new species.

The second expedition, called SUBSEA (Subtropical Underwater Biogeochemistry and Subsurface Export Alliance), was led by Matthew Church of the University of Montana and focused not on animals but on phytoplankton, the microscopic algae that form the base of the ocean food web. Church’s team worked more than 200 miles offshore in the Southeastern Atlantic Gyre, one of the vast, nutrient-poor regions that make up more than half the ocean’s surface. These gyres are often described as ocean deserts because their surface waters contain so few nutrients, but Church’s team was looking beneath the surface. Phytoplankton living at depth in gyres, below the sunlit surface layer, may be playing a larger role in carbon cycling than scientists previously recognised.

Together, the two expeditions address a gap in climate science that has persisted for decades: how much carbon the ocean’s biological pump actually moves, and how much of that movement is driven by living animals rather than by the passive sinking of dead organic material. Estimates of the contribution of diel vertical migration to total carbon export have ranged from 10 per cent to as high as 80 per cent, depending on the region and the study. The uncertainty is enormous, and resolving it matters because the ocean’s capacity to absorb atmospheric carbon dioxide is central to every climate projection.

Quick Hits

A humpback whale named Timmy is being transported by barge from the Baltic Sea toward the North Sea after weeks of failed rescue attempts. The whale has been stranded in shallow waters near the German city of Lübeck since 3 March, far from its natural habitat in the Atlantic. Multiple attempts to guide it toward deeper water failed. In early April, German authorities gave up, saying they believed the animal could not be saved. Private entrepreneurs then stepped in, funding a rescue operation that lifted Timmy into a flooded cargo barge. The barge, towed by two tugboats, began its journey on 29 April, heading around the northern tip of Denmark via the Skagerrak strait toward the North Sea. The journey will take roughly three days. Scientists are divided on whether the whale is strong enough to survive the trip or will find its way to the open Atlantic if released. Fans are tracking Timmy’s journey in real time. “You could see that the whale fought and wanted to live,” Karin Walter-Mommert, one of the entrepreneurs financing the rescue, told the German newspaper Bild.

The world’s first purpose-built offshore platform for ocean thermal energy conversion has been installed in the Canary Islands. UK-based Global OTEC completed the deployment of its floating platform prototype this week, marking a milestone for a technology that has been discussed for decades but never scaled offshore. Ocean thermal energy conversion, or OTEC, generates electricity by harnessing the temperature difference between warm surface seawater and cold water drawn from the deep ocean. The technology offers continuous, baseload power without the intermittency problems of wind and solar, and it targets a specific market: tropical island nations where most electricity is still generated from imported diesel and heavy fuel oil. Global OTEC estimates that more than 25 gigawatts of existing fossil fuel capacity across tropical islands could eventually be replaced by OTEC systems. Whether the technology can move from prototype to commercial deployment remains the open question.

Hard Truth From The Sea

The UK protects 38 per cent of its seas and 13 of 15 health indicators are failing. The AMOC is weakening faster than the models predicted, and corrections to those models suggest the models were wrong in a direction that made things look better than they are. The ocean’s biological pump moves carbon from the atmosphere to the deep, and scientists are only now sending robots to measure how much. Each of these stories describes a version of the same problem: the distance between what we claim to know about the ocean and what we have actually bothered to measure. The ocean does not wait for our instruments to catch up.

Paid subscribers fund the reporting that tracks what is changing in the ocean and why. If you want accountability journalism on the systems we depend on and the institutions responsible for protecting them, please consider upgrading your subscription.

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See you next week.

- Luke

A 4,000-word Special Feature on deep-sea mining is out this week in Oceanographic Magazine, commissioned by the Charles Douglas-Home Memorial Trust. It is one of the deepest pieces of reporting I have done. It examines the science, the governance, the economics, and the company at the centre of the most advanced attempt to mine the deep ocean, a Canadian-listed firm called The Metals Company.

Read the full article in Oceanographic

If you’ve subscribed to this Substack and wondered where I went, this was where. The piece took months. Document review, interviews, legal reads, fact-checks. The kind of reporting that does not produce a steady stream of posts, because the work is invisible.

The week before the article published, I sat on a panel at The Conduit Club in London alongside Louisa Casson, who leads Greenpeace’s global anti-deep-sea-mining campaign, and Oliver Steeds OBE, founder of Nekton and director of the UN’s Ocean Census. The event was called The Scramble for the Seabed. The room was full. It was chaired by Jeevan Vasagar, climate editor of The Observer.

The Metals Company was invited.

They sent a video message in their place.

In it, an unnamed company spokesperson argued that what deep-sea mining would do to the seabed should not be called habitat destruction. The correct word, they said, was modification. The video also disputed the idea that sediment plumes would significantly affect untouched areas of the seabed. Both claims are contested by the peer-reviewed science I examine in the Oceanographic piece.

The panel watched the video. Then we took our seats. There was no one in the room to defend the position the video had just put forward.

That, in itself, is part of the story. The most advanced commercial attempt to mine the deep ocean is being made by a company that, when offered a serious public forum to argue its case, declined to send a person.

Recycling came up early. I had raised it briefly; Louisa Casson made the case in detail. The metals we need for the energy transition are largely already above ground, in old phones, batteries, cars. The systems to recover them at scale do not yet fully exist. We are reaching for the deep sea before we have built the alternatives to it.

Later, an audience member working in green energy asked the question I had been dreading. He was not attacking the panel. He was genuinely uncertain.

What’s the balance? We can debate whether deep-sea mining is good or bad. But we are heading in a direction where it almost feels inevitable. So, do we allow it and govern it carefully? Or do we say no, and slow the transition away from fossil fuels?

I took it first.

What I said, more or less, was this. We are at a real moment of transition, and the world does need metals to power it. But people have zeroed in on deep-sea mining as the only alternative to terrestrial mining, and that framing is largely driven by the financial interests of the companies that want to mine. We need to know for sure the damage this will produce before we can press go or say no. Science has to win out.

That was the answer. It was not the cleanest, but it was honest.

The strongest line of the night was Casson’s.

“The idea of mining the deep sea is like burning a library when you haven’t even finished reading the first book.”

Ninety per cent of the species being found in the Clarion-Clipperton Zone, the patch of Pacific seabed at the centre of the mining race, are new to science. We do not yet know what we would be losing.

Oliver Steeds put the financial case in similar terms. The economics of deep-sea mining, he argued, do not add up before you even consider the environmental costs. Major mining companies have pulled out. Lockheed Martin has divested. A previous attempt in Papua New Guinea collapsed and left the government as a creditor with no recovery mechanism. The Norwegian government opened the Arctic seabed to exploration in January 2024, then halted its licensing programme until at least 2029.

The article goes deeper than I can here. The 1980 US law The Metals Company is filing under, which the International Seabed Authority says has no authority over the international seabed. The unfinished rulebook fifteen years in the making. The 44-year-old machine tracks still visible on the abyssal plain from a 1979 test. The food web disruption that could carry mining sediment into the depth band where mercury enters the human food chain. The science being funded, in significant part, by the companies that want to do the mining.

And the question the panel could not resolve, because the world has not resolved it yet.

Read the full article in Oceanographic

Commissions like this one, from the Charles Douglas-Home Memorial Trust, are rare, and they make ambitious reporting possible. But the work between commissions is what your subscriptions support: the calls that go nowhere, the documents that do not pan out, the months when nothing is publishable. The CDHMT funding bought the time to write the article. Your subscriptions buy the time to find the next one.

Thank you for sticking around.

Reporter’s note: Research support was provided by Blue Marine Foundation, which has publicly supported a precautionary pause on deep-sea mining. The article was researched and written independently. Blue Marine had no editorial control over its findings or conclusions. The Conduit panel referenced above was held on Tuesday 21 April 2026 in collaboration with Pranvera Shema Smith, founder of On Front Line, and chaired by Jeevan Vasagar, climate editor of The Observer. Luke McMillan is Head of Hunting & Captivity at Whale and Dolphin Conservation. The views in this post are his own and do not represent WDC’s institutional position.

In a warehouse somewhere in Iceland, fin whale meat from the 2023 hunt is still sitting unsold. Japan, the only export market, has stopped buying it. The whaling company that killed those animals lost roughly $20 million over eight years of operations. The government has publicly committed to banning commercial whaling this autumn. And yet, earlier this month, that same company announced it intends to hunt fin whales again this summer. Whether it does depends on a single decision by a single minister who has already said the practice is not in the public interest.

That story leads this week’s Deep Brief, alongside a photojournalist’s account of Indonesia’s shark meat trade, where the world’s second-largest animal by global trade value now sells for 29 cents a skewer, and a legal challenge that could force France to confront the tens of thousands of seabirds dying in its fishing nets each year. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

Iceland’s government says it will end whaling. Hvalur hf. is betting it won’t.

Iceland’s whaling company Hvalur hf. has announced its intention to hunt fin whales in 2026, despite two consecutive seasons without a hunt, a government commitment to introduce legislation banning commercial whaling later this year, and an Icelandic warehouse full of unsold meat from the last hunt in 2023.

The decision now rests entirely with Hanna Katrín Friðriksson, Iceland’s Minister of Industries. Friðriksson has publicly stated that commercial whaling is not in the public interest and has confirmed that legislation to end the practice will be tabled this autumn. For conservation groups, that makes any decision to authorise a 2026 hunt difficult to justify.

“Not a single whale should die this summer for a practice the government itself has said it will end this autumn,” said Valgerður Árnadóttir, Chair of Hvalavinir, an Icelandic whale conservation organisation.

Fin whales are the second-largest animals on Earth and are listed as Vulnerable on the IUCN Red List. Iceland is the only country in Europe that still hunts them. Only three nations continue commercial whaling in defiance of the International Whaling Commission’s moratorium: Iceland, Norway, and Japan.

The Marine and Freshwater Research Institute has issued advice capping any fin whale catch at 150 animals, a reduction of roughly 20 per cent on previous quotas. Hvalur hf. holds a five-year licence issued in late 2024, with a combined annual quota permitting up to 400 whales.

The economics of Icelandic whaling have been deteriorating for years. Between 2012 and 2020, Hvalur hf. recorded combined losses of approximately three billion Icelandic krónur, around $20 million, from its whaling operations. Japan, historically the sole export market for Icelandic fin whale meat, has stopped importing it, weighed down by its own stockpiles and falling domestic demand. By contrast, whale watching generates an estimated $26 million annually for Iceland’s economy.

The welfare case is equally difficult to defend. In 2023, one in five fin whales shot required a second harpoon and suffered for up to 35 minutes before death, in what I have argued publicly constitutes a breach of Iceland’s own animal welfare legislation. WDC is calling on the Minister to revoke Hvalur’s licence immediately and to begin the formal process of withdrawing Iceland’s reservation to the International Whaling Commission moratorium.

Three previous ministers have opposed whaling and none succeeded in stopping it. The pattern is familiar: governments declare their opposition, promise legislation, and then allow another season to pass while the bills wait in a queue. Each time, more whales die for a product that nobody is buying.

Disclosure: I am Head of Hunting and Captivity at Whale and Dolphin Conservation. I am quoted in the Oceanographic article by Rob Hutchins that prompted this story. The analysis and framing here are my own.

In Indonesia, shark meat has quietly become bigger business than shark fins. A photojournalist went to see what that looks like.

Indonesia consistently ranks as the top shark-catching nation in the world. At the fish market in Tanjung Luar, a village on the island of Lombok, photojournalist Garry Lolutung documented what the trade looks like up close for Mongabay.

Fishing boats from nearby islands arrive each morning carrying fresh catches. Sharks are placed on the auction floor and sold for 600,000 to one million rupiah each, roughly $35 to $58. The sharks are supplied by longline vessels that deliberately target them, which is generally legal in Indonesia, and by gillnet fishers who take them as bycatch.

Twenty kilometres inland, in Rumbuk village, the meat is processed into smoked jerky, shredded fish, crackers, meatballs, fish cakes, and satay. A kilogram of shark meat in Rumbuk costs between $1.46 and $2.33. A skewer of shark satay costs 5,000 rupiah, which is 29 US cents. It is an affordable source of protein that has become a local staple.

The global picture has shifted. For decades, the shark fin trade dominated. Shark fin soup remains a luxury item in parts of East Asia, and fins are still by far the most valuable part of the animal per kilogram. What has changed is that shark meat has overtaken fins in both trade volume and total value. A 2021 WWF report placed the value of all shark and ray meat traded globally between 2012 and 2019 at $2.6 billion.

Indonesia is a major exporter of shark products, including meat, liver oil, and skin, and its bilateral trade with China represents the world’s fifth-largest flow for blue shark meat, according to a 2022 Oceana report. Researchers have identified significant discrepancies between Indonesia’s reported shark landings and its declared exports, and between its export figures and what its trading partners report importing. This points to a combination of illegal trade, inconsistent data collection, and high levels of domestic consumption.

Protections for sharks in Indonesia exist for some species. Whale sharks, sawfish, and manta rays are protected by law. Fishers in Tanjung Luar told Mongabay they would not hunt whale sharks, citing a long-standing belief that the animals bring good luck. For most other shark species, including threatened ones, hunting is legal.

Shark meat made national headlines in Indonesia in September 2025, when 16 students at a school in Ketapang district on the island of Borneo were poisoned by shark meat served through the national free school meals programme. Other countries, particularly Brazil, have faced scrutiny for including shark meat in school and institutional meals, because the flesh tends to contain high concentrations of heavy metals that can harm human health, especially in children.

Globally, shark and ray populations have declined steadily due to overfishing, combined with the animals’ slow growth and reproduction rates. The market in Tanjung Luar, where baby sharks lie on the auction floor beside adults and fins dry on racks in the sun, is one window into a trade that is accelerating even as the animals that sustain it disappear.

Three environmental groups have taken France to its highest court over the killing of tens of thousands of seabirds.

ClientEarth, Sea Shepherd France, and Défense des Milieux Aquatiques filed a complaint before the Conseil d’État on 21 April 2026, demanding that French authorities enforce existing EU laws on fishing sustainability and biodiversity protection. The groups allege that France has failed to collect adequate data on seabird deaths in fishing gear and has not implemented measures to reduce them, in breach of the Birds and Habitats Directives, the Technical Measures Regulation, and other European legislation.

Scientific extrapolations from available monitoring suggest that France may have the highest seabird bycatch figures in Europe, with an estimated 34,600 birds killed annually. The most affected species include the Balearic shearwater, a medium-sized seabird that breeds in the western Mediterranean and is classified as critically endangered on the IUCN Red List, the northern gannet, now classified as near threatened, and the common guillemot, classified as endangered. Longlines, gillnets, and pelagic trawls targeting commercial species including hake, sea bass, and tuna are the main killers.

Most of the birds drown without ever washing ashore, which is why the crisis has remained largely invisible to the public and to policymakers. Because most deaths happen underwater and the bodies sink, the scale of the problem only becomes clear through observer programmes on fishing vessels and statistical extrapolation, both of which the NGOs argue France has failed to maintain adequately.

The legal action complements an infringement procedure already opened by the European Commission against France for similar failings. The Commission has challenged France on this issue before, and France has not responded with the monitoring or mitigation measures required by European law.

One French fisherman, identified by the pseudonym Ludovic in the case briefing, described a worsening dynamic. Declining fish stocks have led some operators to leave nets in the water for longer, increasing the chance that birds and other non-target species become entangled. “The best way to avoid bycatch is to fish at night and haul the nets back before sunrise,” Ludovic told the briefing. He warned that current trends could create a cycle that depletes fish populations, protected species, and the future of fishing itself.

France oversees the world’s second-largest exclusive economic zone. The gap between that global reach and its failure to monitor what is dying in its own nets is the core of the legal challenge.

Quick Hits

Chile’s new president has suspended two vast marine parks that his predecessor created on his last day in office. Former President Gabriel Boric signed a decree on 10 March creating Juan Fernández II and Nazca-Desventuradas II, which together would have protected roughly 337,000 square kilometres of Pacific Ocean, around 10 per cent of Chile’s exclusive economic zone. President José Antonio Kast suspended the decree on his first day in office as part of a broader review of environmental measures. The region has one of the highest rates of endemic species in the world, higher than the Galápagos or Hawai’i, with 87 per cent of fish in the Juan Fernández archipelago found nowhere else. Conservation groups fear the protections could be weakened under pressure from fishing interests, particularly the semi-industrial swordfish fleet. If the parks survive, Chile would join Palau as the only countries to protect more than half their exclusive economic zones.

Singapore’s Resorts World Sentosa will stop sourcing wild dolphins and is suspending its captive breeding programme. The resort obtained 27 Indo-Pacific bottlenose dolphins from the Solomon Islands in 2008 and 2009. At least four died during transit or from infections. The facility still holds more than 20 dolphins, the youngest a seven-year-old male named Kenzo. An expert panel is being assembled to determine the animals’ future. Staff who spoke to Mongabay said they doubted the dolphins could survive in the wild after so long in captivity. An international movement against cetacean captivity for entertainment is growing, with Mexico, Canada, and France among the countries that have recently banned the practice.

More than 17 million Americans along the Atlantic and Gulf coasts are living in areas at the highest risk of flooding, according to a new study in Science Advances. Researchers at the University of Alabama used 16 factors related to hazard, exposure, and vulnerability, combined with three machine learning models and historical damage data from FEMA, to identify eight cities at greatest risk: New York, Norfolk, Charleston, Jacksonville, Miami, Mobile, New Orleans, and Houston. New York has the largest population at risk, with roughly 4.75 million people in the two highest risk categories. New Orleans has the highest proportional exposure, with 99 per cent of the city’s population at elevated flood risk. The lead author, Wanyun Shao, described the figures as “shocking” and “alarming.”

Hard Truth From The Sea

A minister in Reykjavik is deciding whether to authorise a hunt for an animal the government has already said it will stop killing. A warehouse of unsold whale meat sits in storage while the decision is made. In Indonesia, baby sharks lie on auction floors beside adults, feeding a trade that has grown even as the populations that sustain it have shrunk. In France, tens of thousands of seabirds drown in fishing nets each year, and nobody has to watch because the bodies sink. The ocean absorbs a great deal of what humans would rather not see. The question, as always, is whether the things we choose not to look at will still be there when we finally do.

Paid subscribers fund the reporting that tracks what is changing in the ocean and why. If you want accountability journalism on the systems we depend on and the institutions responsible for protecting them.

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See you next week.

- Luke

Six hundred metres below the surface of the Pacific, off the coast of Long Beach, California, a hollow concrete sphere the size of a small house will soon sit on the seabed. When electricity is cheap, a pump will force seawater out of it, leaving a vacuum inside. When electricity is needed, a valve will open, and the ocean’s own pressure will drive water back in through a turbine, generating power. The sphere is a battery, and the ocean is the charger. If it works, there are plans for fields of them.

This is the Good News Edition. Once a month, this newsletter reports on what is working: the engineering, the science, the governance, and the people who are building, measuring, and protecting, often in places nobody else is looking.

Deep Dives

The ocean floor as a battery. A German-American experiment off California could change how the world stores renewable energy.

The problem with solar and wind power has never been generation, it has been storage. The sun does not shine at night and the wind does not blow on command, so every country trying to run its grid on renewables eventually hits the same wall: what do you do with the surplus electricity when you have too much, and where do you find more when you run out?

One answer, tested successfully on a small scale in 2017 and now heading for its first full-size ocean trial, is to store that energy underwater in concrete spheres.

The StEnSea project, short for Stored Energy in the Sea, was developed by the Fraunhofer Institute for Energy Economics and Energy Systems Technology in Germany. The concept borrows from pumped hydroelectric storage, the most established form of grid-scale energy storage on Earth, which works by pumping water uphill into a reservoir when power is cheap and letting it flow back down through turbines when power is needed. Pumped hydro is efficient, reliable, and well understood. It also requires mountains, dams, and large tracts of land, which limits where it can be built and often generates public opposition.

StEnSea replaces the mountain with the ocean. A hollow concrete sphere on the seabed acts as the lower reservoir. The surrounding ocean acts as the upper one. When surplus electricity is available, it powers a pump that forces seawater out of the sphere, creating a pressure differential with the ocean outside. When the grid needs power, the valve opens, water rushes back in under the enormous pressure at depth, spins a turbine, and feeds electricity back to shore.

In 2017, the Fraunhofer team tested a three-metre prototype in Lake Constance in Germany. It worked. The system handled repeated charge-discharge cycles through the winter and proved the engineering was sound. The next step is a nine-metre sphere, weighing 400 tonnes, to be built using 3D concrete printing by Sperra, a US startup based in Long Beach, and deployed at a depth of 500 to 600 metres off the California coast by the end of 2026. The US Department of Energy has invested $4 million in the project. The German government is contributing roughly €3.4 million.

The prototype will store 0.4 megawatt-hours of electricity, enough to power a typical home for about two weeks. That sounds modest, but the technology is designed to scale. A park of six full-sized spheres, each around 30 metres in diameter, could deliver 120 megawatt-hours of storage and 30 megawatts of power output, cycling hundreds of times a year. The Fraunhofer team estimates a global storage potential of 817,000 gigawatt-hours across suitable coastal seabeds worldwide, based on depth, seafloor slope, and proximity to ports and grid infrastructure.

The efficiency of the system sits at around 75 to 80 per cent, slightly below pumped hydro on land. The lifespan of the concrete spheres is estimated at 50 to 60 years, with turbines and generators needing replacement roughly every 20 years. The estimated cost is 4.6 euro cents per kilowatt-hour stored, competitive with many existing grid-scale storage technologies.

There are unknowns. The California deployment is the first time the system will operate in saltwater at depth, which introduces corrosion, biofouling, and maintenance challenges that did not exist in Lake Constance. Environmental assessments from the lake trial suggested low impact under the conditions tested, but ocean ecosystems at 600 metres depth are different, and the effects of deploying large numbers of spheres on deep-sea habitats have not been studied. These are questions that need answering before any large-scale rollout.

The logic of the design is what makes it compelling. The deeper the water, the greater the pressure, and the more energy each sphere can store. The spheres can be manufactured on shore and towed to site. They require no land, generate no emissions in operation, use no rare materials, and sit out of sight on the seabed. If the California trial succeeds, the technology could pair directly with offshore wind farms, storing their surplus output within reach of the turbines that produce it.

One bay, 28 years, every week. The quiet science that makes Antarctic research possible.

It is 8.30 in the morning at Rothera Research Station on the Antarctic Peninsula, and the marine team is gathered for its daily briefing. Outside, Ryder Bay stretches into a pewter sky. Someone checks the weather. Someone checks sea ice conditions. Within fifteen minutes, a decision is made: it is a sampling day.

The Rothera Time Series, known as RaTS, has been running since 1997. Every five to seven days, weather and ice permitting, a small rigid inflatable boat pushes out from the station ramp into the bay, carrying Niskin bottles for water sampling and a CTD instrument that measures conductivity (a proxy for salinity), temperature, and depth as it descends through the water column. The team profiles to roughly 500 metres and collects water samples at 15 metres depth. They have been doing this, in one form or another, for nearly three decades.

What they are building is one of the most significant long-term ocean measurement records in Antarctica, and one of the very few that includes winter data from either pole. Almost all Antarctic ocean science happens in the austral summer, when ships can reach the continent and conditions permit fieldwork. RaTS runs year-round because Rothera is staffed through the winter, and because the marine team can reach Ryder Bay by boat or, when sea ice covers the surface, by sled. That winter coverage makes the dataset exceptionally valuable. The processes that control how the Southern Ocean absorbs heat and carbon dioxide, the formation of sea ice, the behaviour of phytoplankton, the timing of seasonal cycles, all of these look different in winter than in summer, and almost nobody else is measuring them.

The data has already shown that the ocean around the Antarctic Peninsula is sensitive to large-scale global climate patterns, including El Niño. Summer ocean surface temperatures in the region have increased by more than 1°C. Atmospheric temperatures on the peninsula rose by almost 0.4°C per decade in the second half of the twentieth century, making it one of the most rapidly warming regions in the Southern Hemisphere.

Rothera itself has undergone a transformation. The £670 million Antarctic Infrastructure Modernisation Programme, the largest UK government investment in polar science infrastructure since the 1980s, has delivered a new research vessel (RRS Sir David Attenborough), upgraded wharves, a new runway, and the Discovery Building, a £100 million facility that in April 2026 became the first building in Antarctica to achieve an Outstanding BREEAM sustainability rating, a standard met by fewer than one in a hundred accredited buildings globally. The building is on track to reduce the station’s carbon emissions by 25 per cent through combined heat and power generators, waste heat recovery, solar panels, and automated heating systems.

None of this makes headlines, and it is not meant to. Long-term monitoring is, by definition, unglamorous. It requires people willing to work long hours in a constantly changing environment, to exercise judgement about when conditions are safe enough to go out on the water, and to hand something precious on to the next person without hesitation. “It’s never your data set,” said Allie Mayall, a former marine team lead at Rothera, in the BAS blog post that prompted this story. “You’re just the person looking after it for that time being.”

That care is the infrastructure that everything else depends on. The climate models that predict ice sheet behaviour, the assessments that inform international policy, the studies that track how ecosystems respond to warming, all of them need continuous data from places like Ryder Bay. RaTS is a commitment as much as a monitoring programme, sustained across nearly three decades by the people who go south to keep it running.

On a Mediterranean beach, 3D-printed modules inspired by mangroves are trying to hold the coastline together.

The Gulf of Lion, along the southern coast of France, is losing sand. Storms strip it from beaches faster than natural processes can replace it. In the 2010s, local authorities spent millions of euros on beach replenishment, dredging sand from offshore and pumping it back onto the shore. The sand was supposed to last a decade, but storms stripped most of it away in less than five years.

Lineup Ocean, a French startup, is testing a different approach. Their SURFREEF project, deployed at the beach of Zénith in Palavas-les-Flots near Montpellier, uses submerged structures called UpBlock modules to break the energy of incoming waves before they reach the shore. The modules are 3D-printed from a bio-based material described as low-carbon shell mortar and are designed to mimic the way mangrove root systems dissipate wave energy naturally. Where traditional coastal engineering fights the ocean with seawalls and rock armour, the SURFREEF approach works with the water, reducing the force of waves gradually so that sand has a chance to accumulate rather than being stripped away.

The project is still in its early stages. A baseline mapping of the beach was completed using drone-mounted bathymetric LiDAR (a laser scanning system that measures the shape of both the water surface and the seabed beneath it), and the first demonstrator segment of UpBlock modules is being installed. The next data collection will happen after the first storm, when researchers will measure whether sandbanks have shifted in the way the models predict.

Lineup Ocean won the Eco-Enterprise Innovation Trophy at France’s national eco-enterprise forum in 2026 and received a trophée de reconnaissance from the municipality of Palavas-les-Flots. The SURFREEF project has been granted a five-year temporary occupation authorisation for the maritime public domain by the Hérault prefecture, and a larger project called BIOMIM’4SHORE, backed by €375,000 in French government funding through the i-Lab innovation competition, aims to deploy a full range of nature-based coastal resilience solutions across the town by 2027.

The engineering is modest in scale but interesting in principle. Rather than armouring the coast against the sea, it is attempting to rebuild the conditions under which the coast can protect itself. Whether the modules hold up under real storm conditions, and whether the ecological benefits (increased biodiversity, habitat creation on the submerged structures) materialise as hoped, remains to be demonstrated. The early results will matter for Mediterranean coastal communities that are running out of sand and running out of options.

Quick Hits

Forty-six countries, including major oil and gas producers, will gather in Santa Marta, Colombia later this month for the first international conference dedicated to transitioning away from fossil fuels. Co-hosted by the governments of Colombia and the Netherlands, the conference runs from 24 to 29 April and will bring together government representatives from countries including Canada, Australia, Brazil, Norway, Angola, and several Pacific island nations. The conference operates outside the UN consensus framework that has repeatedly failed to include fossil fuel language in COP final texts, using majority rule instead. One area of focus relevant to ocean governance: new analysis by Earth Insight shows that 19 per cent of the world’s Marine Protected Areas are already overlapped by active oil and gas blocks. The concept of Fossil-Free Zones, geographically defined areas where fossil fuel extraction is permanently off limits, will be central to discussions.

The EU and Iceland held their first annual high-level dialogue on ocean cooperation in Reykjavik on 17 April. Commissioner for fisheries and oceans Costas Kadis met with Iceland’s Minister of Industries Hanna Katrín Friðriksson to review progress under a Memorandum of Understanding signed in July 2025. Topics covered included Arctic governance, management of shared fish stocks in the North-East Atlantic, the blue economy, and mutual commitment to ratifying the High Seas Treaty. During the visit, Kadis travelled to Grindavík, the coastal town severely affected by volcanic eruptions since 2023, to meet with local fishing communities. Iceland is expected to hold a referendum before 2027 on reopening EU accession talks.

The UNFCCC Standing Committee on Finance has chosen “Financing Climate Action in Water Systems and the Ocean” as the topic of its 2026 Forum. The SCF Forum selects a different theme each year, and this is the first time the ocean has been chosen as the focus, a decision supported by submissions from UN-Water, UNICEF, and private sector actors including Fugro. The forum will feed into the 2026 UN Water Conference scheduled for 2 to 4 December in the United Arab Emirates. Combined with the Santa Marta fossil fuel conference and the ongoing BBNJ treaty implementation process, 2026 is turning into a year in which the institutional plumbing for ocean governance is being assembled faster than at any point in the past decade.

Hard Truth From The Sea

The good news in this edition is evidence that effort produces results, which is a different thing from optimism. A concrete sphere works as a battery because the physics was tested, refined, and funded over fifteen years. A monitoring programme in Antarctica exists because people kept going out on the water every week for twenty-eight years. A beach in the south of France might hold its sand because engineers studied how mangroves break waves and then 3D-printed the principle into concrete. Each of these stories started with someone deciding to do the work, and then keeping at it long after anyone was paying attention.

Paid subscribers fund the reporting that tracks what is working in the ocean and why. If you want accountability journalism on the systems that protect the ocean and the people building them.

See you next week.

- Luke

South Africa’s coastal fishing communities have forced the courts to intervene against offshore seismic and drilling permits five times since 2021. The blasting may have happened regardless. This is an Ocean Rising investigation, part one.

In March 2022, a fourth-generation fisher named Christian John Adams went to the Western Cape High Court in Cape Town and heard a judge confirm what he had argued for months: an Australian seismic company had begun firing airguns across the seabed off his fishing grounds without consulting his community, without obtaining the required environmental authorisation, and without so much as translating its notices into isiXhosa, one of the three official languages of the Western Cape.

The company’s executive vice-president, Alan Hopping, said South Africa was “un-investable for us.”

Four months later, they were back.

This is a story about how South Africa’s offshore oil and gas permitting system is designed, and what that design means for the fishing communities that depend on the same waters.

What a seismic survey actually is

A seismic survey for oil and gas works by firing compressed air from guns towed behind a ship. The blast, at Searcher’s source level roughly 255 decibels measured underwater and one of the loudest sounds produced by human activity, travels down through the water, hits the seabed, bounces back, and is captured by sensors trailing behind the vessel on cables stretching 8.1 kilometres. The returning signals are used to map what lies beneath the seabed: the geological formations that might contain oil or gas. (Underwater decibels are measured relative to one micropascal at one metre, a different scale to in-air decibels, but at this source level the signal is detectable thousands of kilometres away; airgun noise from surveys has been recorded at ranges exceeding 3,000 kilometres.)

The blasts repeat every ten seconds, around the clock, for months at a time.

For marine life, the noise is unavoidable. Fish with swim bladders (the air-filled organ that controls buoyancy) can suffer physical injury close to the source. Further away, evidence from multiple studies points to behavioural disruption: fish move, stop feeding, alter their migration routes. The science is genuinely contested. A large-scale Australian study published in PNAS in 2021, partly funded by the oil and gas companies Santos and Woodside, found no evidence of short-term or long-term effects on demersal fish populations on the North West Shelf of Western Australia. An Australian research team published a preprint in 2025 with starkly different findings: catch rates for eastern school whiting fell by 99 per cent following a 3D seismic survey, with effects persisting for at least ten months, and tiger flathead fell by 75 per cent. The authors attributed the declines to fish displacement rather than mortality, and the methodology has not yet been through peer review. What both studies agree on is that results vary significantly by species, and that the cumulative effect of repeated surveys in the same waters has barely been studied anywhere.

Snoek, the fast, predatory fish that is as close to a cultural staple as the West Coast has, has never been studied in this context. No species-specific research exists on what seismic surveys do to snoek populations. What West Coast fishers know is what they observe: that snoek are harder to find, that seasons are shorter, that the effort required to catch the same haul keeps increasing.

Whether that is because of seismic surveys, climate change, overfishing, or some combination, no institution has been tasked with finding out.

This is where the Ocean Rising investigation begins. What follows, the legal record, the permitting pattern, and the structural question no one in government wants to answer, is for paid subscribers.

Read more

Stretched across the Atlantic at twenty-six and a half degrees north, running from the Bahamas toward the Canary Islands, a network of anchored instruments has spent the past two decades measuring how much water is moving through the ocean’s largest heat engine. They record temperature, salinity, velocity and pressure to build a continuous picture of the current that keeps Europe warm. This week, scientists using that data published the strongest direct observational evidence yet that the engine is slowing down across four separate locations in the Atlantic basin.

That story sits alongside a study of four sperm whales that washed ashore in the southeastern United States with fishing gear in their stomachs and undersized squid in their guts, and research into how the planet’s most powerful ocean current, a flow carrying more than a hundred times the water of every river on Earth combined, first came into being. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

The Atlantic’s great heat engine is slowing. Scientists now have the strongest evidence yet.

The Atlantic Meridional Overturning Circulation, known as the AMOC (the word meridional just means running north to south), is a system of ocean currents that moves warm, salty water from the tropics north toward the Arctic, releases its heat into the atmosphere, and sends the cooled, denser water back south along the seafloor. It is the reason Western Europe has milder winters than parts of Canada at the same latitude, and it is part of the global conveyor belt that redistributes heat around the planet. Climate scientists have warned for years that it is slowing down, and that a complete collapse would reshape weather, rainfall, and sea levels across much of the Northern Hemisphere.

A new study led by Qianjiang Xing at the University of Miami, published this week in Science Advances, now provides what the German oceanographer Stefan Rahmstorf, who was not involved in the work, called the strongest direct observational evidence so far that the AMOC is weakening.

The researchers drew on data from RAPID-MOCHA, a network of anchored instruments that has monitored the Atlantic since 2004. The array stretches across the ocean at roughly 26.5 degrees north. It measures temperature, salinity, and water velocity, which together allow scientists to estimate pressure on either side of the basin. Pressure differences matter because water flows from high pressure to low pressure, the same way air moves from a pumped-up tyre when you open the valve, so changes in pressure across the ocean are a direct fingerprint of how much water is moving. The team examined pressure data from three additional mooring arrays installed since 2004 along the western side of the Atlantic, the side closest to North America, off the West Indies, the US East Coast, and Nova Scotia. Across all four locations, the signal was consistent: the circulation is weakening, and the weakening is real, not an artefact of one mooring or one latitude.

The measured decline, based on RAPID-MOCHA data alone, amounts to roughly 10 per cent between 2004 and 2023. The margin of error on that figure is almost as large as the figure itself, which is why the pressure analysis matters. When Xing’s team looked at pressure data from the other three arrays, the weakening became clearer and the uncertainty dropped. The signal that started along the western side of the basin was propagating across the wider Atlantic.

There is a complication to flag. In 2024, a separate team led by Denis Volkov at NOAA published findings showing that the Florida Current, which forms the beginning of the Gulf Stream and is itself a key component of the AMOC, has remained remarkably stable over forty years of observations. Volkov’s team noted that their finding did not refute a broader AMOC slowdown. The AMOC is not one current but a system with multiple branches that can behave differently at different depths and latitudes, which means Xing’s study does not contradict Volkov’s so much as suggest that the weakening is showing up in parts of the system that Volkov’s instruments do not monitor.

The underlying mechanism that scientists worry about is simple in outline. As the Greenland ice sheet melts, fresh water pours into the North Atlantic, and fresh water is less dense than salty water. Less dense water does not sink as readily, which means the cooled water at the northern end of the conveyor belt struggles to descend and complete the loop. If the loop slows enough, it can reach what physicists call a tipping point, beyond which the entire system reorganises into a weaker state. Climate models have predicted this for decades, and the instruments in the water are now starting to see it.

The consequences of a significant AMOC slowdown, according to climate modelling, would include colder winters across Northern Europe, disruption to the monsoon rains that sustain agriculture across parts of Africa and Asia, and a pronounced rise in sea levels along the US East Coast. None of these would happen overnight, and a collapse, if it came, would unfold over decades. What Xing’s study adds is observational evidence that the process which might lead to one has already begun.

In January 2026, Iceland formally classified a potential AMOC collapse as a national security risk. Other countries have not yet followed.

Four sperm whales washed ashore with empty stomachs and pockets full of fishing gear.

Between 2020 and 2022, four sperm whales stranded separately on the beaches of Florida and Alabama. Each was alive when found, and each died shortly afterwards. Because they were alive at the time of stranding, researchers were able to conduct full post-mortem examinations, which is rare. Most stranded whales have decomposed by the time anyone reaches them, destroying the tissue evidence that might explain what killed them.

The four whales were examined by a team led by Jennifer Bloodgood, now at Cornell University, along with collaborators at the Dauphin Island Sea Lab and the Harbor Branch Oceanographic Institute. Their findings, published 9 April in the journal Diseases of Aquatic Organisms, describe a consistent pattern across all four animals: emaciation, malnutrition, and in two of the whales, large quantities of ingested fishing gear. One had a length of longline gear, the kind used for commercial deep-sea fishing, with a minimum of 480 branch lines, wrapped around its lower jaw, with a wad of trawl net in its throat and more gear in its stomach. Another had sections of gill net, trawl net and longline gear in its stomach.

The stomach contents also revealed something subtler. The whales had been eating their normal prey, mostly squid, in quantities that should have been enough to sustain them. Two contained well over 1,000 squid beaks, which is how researchers identify what a whale has been eating after the soft body parts have been digested. The beaks allow scientists to estimate the size of the squid the whale was consuming. The beaks in these whales were, on average, smaller than expected. The whales were eating squid, but they were eating smaller, less nutritious squid than sperm whales normally eat.

This matters because a sperm whale that has to eat smaller squid to stay fed has to dive more often and work harder for the same amount of energy. Sperm whales hunt by echolocation, the use of internal sonar to find prey in total darkness. Human activities that produce underwater noise, including seismic surveys for oil and gas exploration in the Gulf of Mexico and the movement of commercial shipping, can disrupt that sonar. The study cannot prove that any specific whale’s death was caused by any specific noise source. What it can do is identify a pattern: emaciated whales, derelict fishing gear in their bodies, a documented trend toward smaller prey, and an environment in which the tools they use to find food are increasingly contaminated by human sound.

“Many of the issues come back to potential human influences,” Bloodgood said in a statement released by Cornell. “We’re the ones causing many of these issues and many of them should be entirely preventable.”

Sperm whales are listed as endangered under the US Endangered Species Act. They were hunted close to extinction in the 19th and 20th centuries, primarily for the waxy oil in their heads, which was used in candles and lubricants. Commercial whaling for sperm whales ended in 1987, and the species has been recovering slowly ever since. The four whales in this study died of something else entirely.

The planet’s most powerful ocean current carries more water than every river combined. Scientists have now worked out how it was born.

The Antarctic Circumpolar Current runs clockwise around Antarctica, uninterrupted by any landmass, carrying more than a hundred times the water that flows in every river on Earth combined. It isolates the southern continent thermally, which is the reason Antarctica has been able to build and hold its enormous ice sheet. It draws down carbon dioxide from the atmosphere. It is, along with the AMOC, one of the two largest circulation systems in the global ocean, and it shapes climate everywhere.

For decades, scientists assumed the current formed when tectonic plates pulled South America and Australia away from Antarctica around 34 million years ago, opening the Drake Passage and the Tasman Gateway and allowing water to flow freely around the pole. That was the moment, the standard explanation held, that the current came into being and the planet began its long slide from a warm world with little permanent ice into the colder state we live in now, with permanent ice caps at both poles. It is a transition climate scientists call the move from a greenhouse to an icehouse climate.

A new study published in the Proceedings of the National Academy of Sciences by a team led by Hanna Knahl at the Alfred Wegener Institute in Germany suggests the standard explanation is incomplete. The opening of the sea gateways was necessary, but on its own, it was not enough to ignite the current.

Knahl and her colleagues ran detailed climate simulations using the geography of the Earth as it was roughly 33.5 million years ago, when Australia and South America were much closer to Antarctica than they are today. They coupled those simulations to a model of the early Antarctic ice sheet developed in a 2024 study. The results showed that even after the sea gateways had widened, the circumpolar current remained weak and incomplete, with strong flow developing in the Atlantic and Indian sectors while the Pacific sector stayed largely stagnant. The planet’s dominant ocean current had not yet come into being.

What eventually ignited it, according to the study, was wind. As Australia continued to drift north, the Tasman Gateway, the sea passage between Antarctica and Australia, eventually lined up with the band of westerly winds that still roar across the Southern Ocean today. Once those winds could blow directly through the gateway without obstruction, they drove the current into its modern, continuous loop, completing the ring around Antarctica. The continent’s thermal isolation deepened, carbon dioxide drawdown accelerated, and the planet cooled into the icehouse state that still defines the present climate system.

The atmospheric CO2 concentration at the time the current was forming was around 600 parts per million. That level has not been reached in the 34 million years since. Current concentrations are around 425 parts per million and rising. Under some projected emissions pathways, the 600 ppm figure could be exceeded before the end of this century.

Knahl urges caution about drawing direct parallels. “The climate of the past can of course not be projected one to one onto the future,” she said in a statement released with the study. The circumpolar current in its infancy, her team found, behaved differently from the mature current that exists today. What the study does make clear is that ocean circulation systems that feel permanent, that have shaped life on the planet for millions of years, depend on configurations of geography, wind, and temperature that are not guaranteed.

Quick Hits

A sleeper shark has been filmed in Antarctic waters for the first time. In January 2025, a camera deployed by the Minderoo-UWA Deep-Sea Research Centre captured footage of a southern sleeper shark cruising at around 500 metres depth off the South Shetland Islands, north of the Antarctic Peninsula. The water temperature was close to freezing. The footage, released in February and circulating again this week, was the first time any shark has been documented this far south. “There’s a general rule of thumb that you don’t get sharks in Antarctica,” said Alan Jamieson, the founding director of the research centre. “And it’s not even a little one either. It’s a hunk of a shark.” The specimen was estimated at between three and four metres in length. Scientists caution against immediately attributing the sighting to climate change. Antarctic waters are among the least studied on Earth, and research cameras operate only during the Southern Hemisphere summer, meaning that for roughly three quarters of the year, nobody is looking at all. The sharks may have been there all along.

An underwater mountain 4,200 metres tall has been mapped north of Palau. In September 2025, NOAA Ship Okeanos Explorer, working as part of the agency’s Beyond the Blue: Illuminating the Pacific campaign, used multibeam sonar to map a seamount roughly 250 miles north of Palau. The feature rises from the deep ocean floor at around 4,400 metres depth to a summit just 243 metres below the ocean surface, making it about half the height of Mount Everest. The seamount had been hinted at in nautical charts published in 2023, but the NOAA survey provided the first high-resolution picture of its shape. Scientists estimate there are more than 100,000 large seamounts on Earth. Less than one tenth of one per cent have been explored. Each one that gets mapped becomes a potential target for biological surveys, because seamounts tend to host dense concentrations of corals, sponges, and fish attracted to the hard substrate and accelerated currents their shapes create.

New Zealand is surrounded by some of the most energetic water on the planet. Tapping it is harder than it looks. Writing for The Conversation and RNZ, physical oceanographer Craig Stevens, who holds a joint position at Earth Sciences New Zealand (formerly NIWA) and the University of Auckland, lays out the country’s marine energy potential and the reasons so little of it has been harnessed. The west coast is swept by waves generated across the Southern Ocean. Cook Strait, between the North and South Islands, is one of the most energetic stretches of tidal water anywhere. Tidal energy globally now accounts for nearly two thirds of the non-wind ocean energy market, and the UK and France are planning 400 megawatts of new tidal stream infrastructure over the next decade. New Zealand, despite the resource, has yet to complete a single tidal energy project. The reasons, Stevens argues, are familiar: high upfront costs, limited economies of scale, cautious investors, and a history of schemes that over-promised what the technology of the day could deliver. A proposed tidal scheme in Kaipara Harbour, north of Auckland, was once billed as capable of powering 250,000 homes. It was never built.

Hard Truth From The Sea

Every ocean system in this week’s brief took millions of years to come into being. The currents that isolate Antarctica and warm Europe assembled themselves slowly, through the drift of continents and the alignment of winds, into states that have shaped life on the planet ever since. Sperm whales evolved into the deep-diving hunters they are today over a similar span of time, refining the sonar they use to find food in total darkness. Humans have managed, in roughly two centuries of industrial activity, to put measurable strain on all three. The relevant question is no longer whether we are changing the ocean. It is whether anyone with the power to act will move before the systems we depend on quietly stop working the way they always have.

Paid subscribers fund the reporting that tracks what is changing in the ocean and why. If you want accountability journalism on the systems we depend on and the institutions responsible for protecting them.

See you next week.

- Luke

Last week in New York, as negotiators gathered for the final preparatory meeting before the first Conference of the Parties to the High Seas Treaty, China arrived with a pitch. According to the Financial Times, which cited three people present at private meetings, China offered more than $70 million in funding for ocean protection, promised to be flexible on visas, and offered immunity to diplomats and assurances of access for campaigners attending future meetings in Xiamen. China’s foreign minister delivered a video message. Its UN ambassador told the room: “In a world of growing uncertainty, China will remain a steadfast pillar of multilateralism.”

The bid is for Xiamen to host the secretariat of the BBNJ (Biodiversity Beyond National Jurisdiction Agreement). This treaty entered into force in January 2026 after nearly two decades of negotiation. The secretariat is the institutional engine of the whole effort. It services the first marine protected areas on the high seas, houses the scientific body, and runs the clearing-house, a central database where countries submit information, through which they share data on marine genetic resources.

Marine genetic resources are biological materials found in ocean species, including deep-sea organisms such as microbes, sponges, and invertebrates, that can be used to develop pharmaceuticals, cosmetics, and industrial compounds. They are potentially worth billions, and until this treaty, entirely unregulated. The high seas are the ocean beyond any country’s exclusive economic zone, the area of ocean where it has sovereign rights over resources, roughly the outer 200 nautical miles from any coastline, covering about two-thirds of the world’s ocean surface. Until January this year, there was no legal framework to create protected areas there, no requirement for environmental impact assessments, and no rules on who profits from genetic resources found in the deep. The BBNJ Agreement changes that.

Whoever hosts the secretariat will shape how the treaty functions in practice. The vote between Xiamen, Chile’s Valparaiso, and Belgium’s Brussels will be taken by the 85 countries that have ratified the treaty as of April 2026, no later than January 2027.

China’s financial offer, if confirmed, is serious. Its institutional capacity is real. The argument about American retreat is not wrong. China co-chaired the COP15 meeting of the Convention on Biological Diversity, where the Kunming-Montreal framework, the global biodiversity agreement reached in Canada in 2022, which set the 30 by 30 target, was agreed. It has ratified the BBNJ agreement. It joined the Port State Measures Agreement, the principal international instrument targeting illegal fishing, in 2023, seven years after the agreement entered into force.

The fishing question

Between 2022 and 2024, vessels flagged to China conducted 44 per cent of the world’s visible fishing activity, according to an Oceana analysis of Global Fishing Watch satellite data. Chinese vessels accounted for 30 per cent of all fishing activity on the high seas specifically. The figures count apparent fishing effort based on vessel tracking signals and exclude vessels that switch off their tracking signals. The figures represent a lower bound on China’s true high seas presence. Independent analysts who have examined satellite tracking data have reached similar conclusions about the scale of China’s high seas presence. Oceana is an advocacy organisation, and these numbers deserve independent scrutiny.

China’s fleet has a larger documented stake in how those high seas zones are drawn than any other single flag state. It is now asking to draw them.

The Antarctic precedent

For six consecutive years, the CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources), the international body responsible for protecting the Southern Ocean, failed to agree on new marine protected areas. Just two nations declined to support the proposals: China and Russia. Three protected areas, covering the East Antarctic, the Weddell Sea, and the Antarctic Peninsula, have been on the table for years, supported by the other commission members and described by independent scientists as grounded in the best available evidence.

The commission operates by consensus. There is no formal veto: any member declining to agree is enough to prevent adoption. Six consecutive years of declining, against the wishes of the other commission members, is the record.

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Somewhere in the mid-Atlantic, a kilometre below the seafloor, hot rock is slowly splitting water molecules and releasing hydrogen. Microbial communities are feeding on it in the dark. Carbonate veins are trapping carbon dioxide in solid mineral form. None of this requires sunlight. None of it requires the surface world at all. Scientists pulled up 1,268 metres of that rock this and published what they found. It is the deepest continuous sample of Earth’s upper mantle ever recovered from the ocean floor.

That story sits alongside research showing that 21% of the global ocean has grown darker in the past two decades, and a governance fight at the United Nations that could determine whether the High Seas Treaty’s promise of marine protected areas survives first contact with the fishing industry. Three deep dives. Three quick hits. One hard truth from the sea

Deep Dives

One fifth of the ocean is getting darker.

Between 2003 and 2022, 21% of the global ocean became darker. Light penetrated less deeply into the water. The zone where sunlight reaches, called the photic zone, where roughly 90% of all marine life lives, shrank. In more than 9% of the ocean, an area larger than Africa, the photic zone contracted by more than 50 metres. In 2.6%, it contracted by more than 100 metres.

These findings come from a study published last year in Global Change Biology by researchers at the University of Plymouth and Plymouth Marine Laboratory, and resurfaced this week through a feature in New Scientist. The team used two decades of NASA satellite data and numerical modelling to track annual changes in photic zone depth across the entire planet.

The causes differ by location. In coastal areas, increased rainfall linked to climate change washes more sediment and nutrients from agricultural land into the sea. Those nutrients feed plankton blooms, which reduce the amount of light passing through the water. In the open ocean, the drivers are less clear. Scientists point to changes in plankton communities driven by rising sea surface temperatures, shifts in ocean circulation, and the increasing frequency of marine heatwaves that alter the conditions phytoplankton need to grow.

The most pronounced darkening appeared in three areas: the top of the Gulf Stream, the Arctic, and the Antarctic. All three are regions already experiencing the most severe effects of climate change.

The implications cascade through the food web. Phytoplankton, the microscopic plants that form the base of almost all marine food chains, need light to photosynthesise. Zooplankton, the tiny animals that eat phytoplankton, use light cues to time their daily vertical migration, the largest movement of biomass on the planet. Fish, seabirds, and marine mammals depend on that migration for food. Coral reefs depend on light for survival. If the lit zone compresses, animals that need light are pushed closer to the surface, where they must compete for food and space in a shrinking habitat.

“If the photic zone is reducing by around 50 metres in large swathes of the ocean, animals that need light will be forced closer to the surface,” said Professor Tim Smyth, head of science for marine biogeochemistry and observations at Plymouth Marine Laboratory. “That could bring about fundamental changes in the entire marine ecosystem.”

The picture is not entirely one-directional. Around 10% of the ocean, more than 37 million square kilometres, became lighter over the same period. The researchers are still investigating why. The overall trend, though, is toward a darker ocean, and the speed and scale of the change are what concern scientists most.

Scientists drilled a kilometre into the ocean floor.

Working from the research vessel JOIDES Resolution, an international team recovered a continuous 1,268-metre-long core of mantle rock from beneath the seafloor at the Atlantis Massif, a geological formation near the Mid-Atlantic Ridge. Published this week in Science, it is the deepest section of Earth’s upper mantle ever sampled directly from the ocean floor.

The mantle is the layer of hot rock between the Earth’s crust and its core. It holds roughly two thirds of the planet’s mass. Until now, scientists had to piece together what it looks like from fragments: ancient mantle rock pushed up onto land, bits carried to the surface by volcanic eruptions, or small samples dredged from fracture zones. Earlier attempts to drill into oceanic mantle barely passed 200 metres and recovered less than half the rock they cut. This core changes that. It provides a nearly complete column from the mantle melting zone up into the base of the oceanic crust.

Most of the rock is a type called peridotite, the dominant rock of the upper mantle, which had been transformed by a chemical reaction called serpentinisation. When seawater percolates down through cracks and meets the hot mantle rock, it reacts with the rock’s original minerals, converting them into new mineral forms. That reaction splits water molecules and releases molecular hydrogen.

That hydrogen is not just a chemical curiosity. Less than a kilometre from the drill site sits the Lost City hydrothermal field, where warm fluids rich in hydrogen, methane, and small organic molecules vent from tall white mineral chimneys and support dense microbial communities in total darkness. Lost City has long been considered a modern analogue for the kind of environment where life may have originated on early Earth, and possibly on ocean worlds like Jupiter’s moon Europa or Saturn’s moon Enceladus. The new core shows that the full depth of mantle beneath this field is heavily serpentinised and cut by multiple generations of mineral veins, supporting the idea that the energy source for these ecosystems is persistent and deep.

The core also revealed abundant carbonate veins threading through the rock, especially where the transformed mantle rock meets intrusions of a denser rock called gabbro. Those veins record carbon dioxide that has been locked away in solid mineral form rather than remaining in seawater or the atmosphere. Similar reactions in mantle rock are being studied as natural models for long-term carbon storage. At the same time, geologists are investigating hydrogen from serpentinisation as a potential source of clean energy. Natural hydrogen accumulations have been documented in several geological settings, and serpentinised mantle rock is one of the main generators.

There is a final twist. The record-breaking hole was drilled in 2023 during International Ocean Discovery Program Expedition 399, near the end of the JOIDES Resolution’s long career. The ship spent nearly four decades as the world’s primary scientific ocean drilling vessel, helping build much of what we know about plate tectonics, past climate, and deep biospheres. In 2024, the US National Science Foundation confirmed that funding for the ageing drillship would not be renewed. The vessel has now ended operations, with no direct replacement yet in the water. This core is both a scientific milestone and a farewell.

The fishing industry is trying to rewrite the High Seas Treaty before it has been used once.

Last week’s Deep Brief covered the High Seas Treaty’s third Preparatory Commission in New York. This week, as that meeting neared its close, a fight emerged over text that could determine whether the treaty can deliver on its central promise: creating marine protected areas on the high seas.

Regional Fisheries Management Organisations, the 17 bodies that already oversee fishing in international waters, proposed amendments to the draft text being prepared for the treaty’s first Conference of the Parties, the summit where member countries will set the rules for how the treaty works in practice. According to Greenpeace, which is tracking the negotiations, the proposed changes would give RFMOs additional powers to block or delay marine protected area proposals and would significantly restrict the treaty’s ability to deliver ocean protection measures.

The proposed text, documented in a UN negotiating document designated CRP6, goes beyond the existing Article 5 of the treaty, which already states that the agreement cannot undermine existing fisheries rules. The amendments would, in Greenpeace’s analysis, shore up RFMO supremacy and give fishing industry interests the ability to stall and derail conservation proposals.

“The organisations that have presided over decades of destruction on the high seas have made a completely unacceptable power-grab which would dramatically weaken the Treaty’s ability to protect the ocean,” said Megan Randles, Greenpeace’s head of delegation to the UN talks.

This matters because the treaty’s value depends almost entirely on whether it can establish marine protected areas that include meaningful restrictions on fishing. If RFMOs can block those proposals, or impose conditions that drain them of substance, the treaty becomes a legal framework without practical force.

The context here is important. RFMOs would argue they are protecting established management systems that have improved significantly in recent decades. Some have. Tuna RFMOs, for example, now manage 87% of assessed tuna stocks sustainably, according to the FAO’s most recent global assessment. The broader picture is less reassuring. A 2010 analysis cited by Dialogue Earth found that 67% of 48 assessed high seas fish stocks were depleted or overfished. High seas catches have risen by more than 400% since the 1950s. The treaty was designed, in part, to fill the governance gaps RFMOs left open. Giving them blocking power over the treaty’s most significant tool risks letting the institutions that oversaw decades of decline dictate the pace of reform.

PrepCom3 was scheduled to conclude on 2 April. The outcome of this text fight will shape everything that follows at the treaty’s first formal summit, now expected by January 2027.

Quick Hits

Zooplankton are pumping microplastics into the deep ocean. Copepods, tiny crustaceans that dominate zooplankton communities across the global ocean, ingest microplastics from the surrounding water, package them into faecal pellets, and sink them through the water column. A study published in the Journal of Hazardous Materials by researchers at Plymouth Marine Laboratory measured the process for the first time in real time and estimated that copepods in the western English Channel transport roughly 271 microplastic particles per cubic metre of seawater per day. With more than 125 trillion microplastic particles estimated to have accumulated in the ocean, even small per-animal contributions add up fast. “Copepods don’t just encounter microplastics,” said Professor Penelope Lindeque. “They are like mini biological pumps, processing and repackaging the microplastics into their faeces, which sink through the water column and accumulate in underlying sediment.”

Forty-year-old canned salmon is telling scientists the ocean may be recovering. Researchers at the University of Washington opened 178 cans of salmon spanning four decades from the Gulf of Alaska and Bristol Bay, counted the parasitic worms embedded in the flesh, and found that levels of anisakids, a common marine roundworm, rose in pink and chum salmon over the study period. That sounds like bad news. It is not. Anisakids need multiple hosts to complete their life cycle, including marine mammals. Rising parasite numbers suggest the food web is intact and that marine mammal populations, protected since the Marine Mammal Protection Act of 1972, have recovered enough to sustain the parasites’ reproduction. The study, published in Ecology and Evolution in 2024, resurfaced this week. “Everyone assumes that worms in your salmon is a sign that things have gone awry,” said Chelsea Wood, a University of Washington fishery scientist. “I see their presence as a signal that the fish on your plate came from a healthy ecosystem.”

The EU has launched its European Ocean Board. Twenty-eight members from trade associations, academia, research institutes, NGOs, and youth organisations met for the first time on 31 March to begin implementing the European Ocean Pact, the EU’s strategy for ocean protection, blue economy, and coastal community support adopted in June 2025. The board is chaired by Costas Kadis, Commissioner for fisheries and oceans. It will advise the European Commission on ocean health, economic competitiveness, maritime security, and international ocean governance. The creation of the board signals that the EU intends its ocean strategy to have teeth beyond the document. Whether it delivers depends on what the board actually recommends and whether the Commission acts on it.

Hard Truth From The Sea

The ocean is getting darker. One fifth of its lit zone has contracted in twenty years. The rock beneath the seafloor is producing hydrogen and trapping carbon in processes that have run for hundreds of thousands of years without human involvement. The fishing industry is attempting to rewrite a treaty designed to constrain it before that treaty has been used once. Each of these stories describes the same tension: the ocean has systems that work. The question is whether the institutions humans have built to manage it will let them.

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See you next week.

- Luke

This chapter didn’t make it into Finlay and the Whale, my forthcoming book about the ocean’s collapse and the systems keeping it that way. The first draft is nearly done. Then comes the search for a publisher. Some of the ideas I cut feel worth sharing on their own terms, and this one has been sitting in a folder long enough.

Imagine it is 1995. Your neighbour pulls into the driveway in a brand-new BMW. The street glances over… admiration, envy, maybe a flicker of pride that one of their own is doing well. The walls are thin, and an hour later you can hear the argument through the plaster. The car was never the whole story.

Fast forward. The walls are thicker, but the windows have been torn off. You see the driveway moment on repeat. The new car, the luxury holiday, the kitchen refit. The arguments and the sleepless nights are cut out. The curation is the point. The image is spotless because the mess has been edited away.

We compare our insides with other people’s outsides. Their gloss becomes our deficit. Every scroll is a prompt telling you that you are behind, you need more.

Your brain is not weak. It is being farmed.

***

In 2014, a film called The Gambler slipped under the radar. Critics were mixed, but buried inside its plot about a debt-ridden literature professor was, in my humble opinion, one of the sharpest monologues on freedom ever put to screen. A loan shark explains life’s real equation:

“You get a house with a 25-year roof, an indestructible economy shitbox car and you put the rest into the system at 3 to 5 percent... That’s your fortress of fucking solitude. That puts you, for the rest of your life, at a level of ‘Fuck You.’ Someone wants you to do something? Fuck You. Boss pisses you off? Fuck You.”

Crude, but also clarifying. The fortress has nothing to do with luxury. It is the ability to live without begging forgiveness from banks, bosses, or anyone else.

When I bought my 16-year-old Volvo, some people mocked it. No sat nav. No CarPlay. A CD player instead of Bluetooth. Dented doors, mismatched wheels, 130,000 miles already on the clock. My friends Dave and Alex, old-car people, gave me kudos. They saw what others missed: no payments, low insurance, cheap to run, a boot big enough for baby stuff, seats that fold flat if you need to sleep in the back on a camping trip.

It is creeping towards 200,000 miles now and still going. Every ignition is relief, not anxiety.

That is the fortress. That is what it feels like.

***

The logic of comparison is ancient and obvious. Humans are status animals. In every tribe and city, knowing where you ranked mattered for survival. Status brought resources, mates, security. That wiring has not gone anywhere.

What has changed is the scale. For most of human history, you measured yourself against a few dozen people you actually knew. Now you measure yourself against thousands of curated feeds, each one engineered to widen the gap.

Then the system offers to close it. Miss a payment? Spread it over four months. Want the new look? Pay later, no questions. They call it flexibility. It is absolution with interest.

The engineers of social platforms know this. They do not just sell ad space. They sell identity loops. Envy, desire, click, defer the cost. Buy now, pay later is a business model built on the distance between who you are and who the feed tells you to be.

The cost lands somewhere real. Outstanding credit card debt in the UK hit £76 billion in 2025. One in four British adults used a buy now, pay later service at least once last year, up from one in seven the year before. The financial regulator looked at what they were buying. The most common answer: lifestyle and beauty purchases. Globally, buy now, pay later spending has gone from $2 billion a decade ago to $342 billion today. Plastic surgeons worldwide performed more than 33 million procedures in 2022 alone, a 41 per cent increase over four years.

The system built a machine to monetise the gap. Then it built another one to finance closing it.

***

Escaping the loop is slow work. Praise the thing that lasted rather than the thing that is new. Post the ordinary dinner instead of the filtered highlight. Before you buy something, ask whether it makes your daily life better or just looks good for a moment. That pause, practised enough, becomes a muscle.

The loop survives because it is invisible, has momentum, and has been normalised. Name it, and it starts to wobble.

***

Ego rarely stays contained. What begins as envy becomes something harder when the scales tilt too far. The neighbour who flashes the BMW is one thing. The executive collecting bonuses after a bailout is another. We do not just measure ourselves against others. We measure whether others are playing fair. When the gap feels rigged, something ancient stirs.

That is where the next loop begins.

The book isn't out yet. It might not find a publisher on the first try. That's how this works. If you want occasional chapters when they're ready, before anyone else sees them, go annual. If you just want the journalism, a paid subscription gets you everything we publish. Either way: I'd like to know what you think about this chapter. Leave a comment below.

In a conference room at United Nations headquarters in New York this week, diplomats from more than 85 countries sat down to decide how the world’s first treaty for protecting the high seas will actually work. Outside, the rules-based international order the treaty depends on is under sustained attack. Inside, delegates debated committee structures, funding mechanisms, and decision-making procedures. The treaty is now law. The institutions to enforce it do not yet exist.

That meeting sits alongside a study revealing how the ocean seafloor processes carbon on a planetary scale, and research turning sea turtle shells into decades-long records of environmental stress. Three deep dives. Three quick hits. One hard truth from the sea.

Deep Dives

The high seas treaty is now law. Making it work is another matter entirely.

The High Seas Treaty, formally the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction, entered into force on 17 January 2026. It took nearly 20 years to negotiate. It covers two thirds of the ocean, the vast expanse beyond any country’s exclusive economic zone, the 200-nautical-mile strip of sea that coastal nations control, where no single government has jurisdiction. For the first time, it provides a legal route for creating marine protected areas in international waters, requires environmental impact assessments for activities that could harm marine life, and establishes rules for sharing the benefits of marine genetic resources, the biological material from ocean organisms that can be used in pharmaceuticals, cosmetics, and other industries.

More than 85 countries have ratified it. The United States signed in September 2023 but has not ratified. President Biden transmitted the treaty to the Senate in December 2024, where it has not progressed. The current administration has not signalled intent to pursue ratification.

This week, the third and final Preparatory Commission is meeting in New York from 23 March to 2 April to hammer out the institutional architecture before the treaty’s first Conference of the Parties. That summit, where member countries will make binding decisions on how the treaty operates, must take place by January 2027. The agenda is procedural: rules of procedure, the structure of a scientific and technical body, the design of a central platform for sharing scientific data and technical support, and the governance of the treaty’s financial instruments.

Three funds sit at the centre of the financial architecture. One relies on voluntary donations to support developing country representatives attending meetings. A second is managed by the Global Environment Facility, an existing multilateral fund. A third “special fund” will draw mandatory contributions from developed countries, set at 50 per cent of their share of the treaty’s budget, alongside potential revenue from marine genetic resources and additional public and private donations. These financial obligations are now legally binding for ratifying states. The money is committed. It cannot flow until the fund’s governance, banking arrangements, and access procedures are established.

The practical challenges start with fishing. A clause in the treaty states it cannot undermine existing laws and organisations or override existing fisheries rules. Seventeen regional fisheries management organisations already oversee fishing across the high seas. Only in unregulated gaps will the treaty have clear authority to shape fishing rules. According to Dialogue Earth, citing FAO data, only about 5 per cent of global high seas fish catch comes from areas with no existing oversight. For everything else, the treaty must negotiate with existing bodies.

Then there is the question of how the treaty interacts with the International Seabed Authority, which governs deep-sea mining. Both bodies are developing environmental impact assessment frameworks. Countries that are parties to both instruments will need to ensure consistency between the two regimes. Any gaps between them could weaken protections rather than strengthen them.

Three countries are competing to host the treaty’s permanent secretariat: Belgium, Chile, and China. China’s bid for the city of Xiamen is particularly notable. Li Shuo, who directs the Asia Society Policy Institute’s China Climate Hub, described it as a significant escalation in China’s engagement with global governance, drawing parallels with Beijing hosting the UN biodiversity summit during the first Trump administration. Lynda Goldsworthy, a researcher on high seas and Antarctic governance at the University of Tasmania, told Dialogue Earth the bid was intriguing but raised concerns, given China’s reluctance to support marine protected areas in the Antarctic high seas.

Experts estimate it could take three years or more before the first marine protected area is established under the treaty. Conservation groups have already identified candidate sites, including the waters covering the Salas y Gomez and Nazca ridges off Chile and Peru, home to scores of endangered species. The distance between identifying a site and establishing legal protection is where treaties either deliver or quietly become irrelevant.

The ocean floor is processing carbon on a scale we could not measure until now.

A study published this week by researchers at the University of Manchester provides the first global-scale predictions of how dissolved organic carbon moves between seawater and marine sediments. Until now, this process was too computationally demanding to model at a planetary scale. The team, led by Dr Peyman Babakhani, solved the problem by training artificial intelligence to reproduce the behaviour of an existing computer model, one that simulates the physical and chemical processes of carbon cycling in ocean sediments. Once trained, the AI could be applied globally.

Dissolved organic carbon is the mix of natural chemicals floating in seawater. When it reaches the seafloor, some of it is absorbed by minerals in the sediment, some is returned to the water column, the full depth of water between the surface and the seafloor, and some is buried. These processes influence how much carbon the ocean stores over long timescales and how much cycles back into the water.

The study, published in *The Innovation*, found that 11 per cent of the particulate organic carbon, the tiny particles of organic matter that sink from the surface, arriving at the seafloor is returned to seawater as dissolved organic carbon. Twenty-four per cent is absorbed onto minerals. Most strikingly, the model predicts that about half of all the solid organic carbon locked in the upper metre of marine sediments got there not as sinking particles from the surface but as dissolved carbon that was absorbed onto minerals on the seafloor. That changes the picture of carbon storage in the deep ocean. It suggests that the interaction between dissolved carbon and mineral surfaces is a larger part of the ocean’s long-term carbon budget than previously recognised.

The methodological finding was almost as interesting as the science. The researchers tested several types of AI, from complex deep learning systems to simple algorithms. The simplest ones were the most accurate. Every time they made the AI more complex, the predictions got worse. That rarely happens in AI development. The old principle that simpler solutions tend to be better usually goes untested.

The framework can now be integrated into the large-scale computer models scientists use to simulate how the ocean and atmosphere work, allowing them to test how marine carbon reservoirs might respond to environmental change in the coming decades.

Sea turtle shells are recording decades of ocean stress. Scientists just learned how to read them.

Sea turtles grow continuously throughout their lives. As they do, their shells grow with them, laying down new tissue in layers. The oldest layers sit on the outside, the newest on the inside. Each layer incorporates chemicals from the surrounding water as it forms, creating a record of environmental conditions at the time.

Scientists have known this for years. The problem was that they could not tell how much time each layer represented. A seven-layer sample might cover seven months or seven years.

A study published this week in *Marine Biology*, led by Bethan Linscott at the University of Miami, solved that problem by borrowing a technique from archaeology. Linscott and her colleagues took shell samples from 24 stranded sea turtles, loggerheads and green turtles collected along the Florida coast between 2019 and 2022. They sliced the samples into sections one twentieth of a millimetre thick and dated each layer using radiocarbon, a naturally occurring form of carbon that decays at a known rate. They calibrated the measurements against the mid-20th century “bomb pulse”, a spike in radiocarbon from nuclear weapons testing that serves as a reference point in the marine environment. Using a statistical method normally applied to date sediment samples in archaeology, they calculated that each layer represents an average time span of seven to nine months.

With a reliable timeline, the researchers could compare the growth records of different turtles. They found periods when all the animals grew more slowly. Those slowdowns lined up with major environmental disturbances in Florida waters: harmful algal blooms known as red tides, and disruptive accumulations of Sargassum seaweed.

The implications go beyond turtles. If shell layers can be reliably dated, every stranded turtle becomes a potential record of environmental conditions stretching back years or decades. Scientists can match changes in foraging patterns and diet with specific environmental events, building a record of how marine ecosystems respond to climate change, pollution, and habitat degradation over time.

“The shells are effectively recording environmental stress in the ocean,” Linscott said.

Quick Hits

Every land animal on Earth descends from the ocean. A study in Nature mapped the genetics of how they got out. Researchers at the University of Bristol and the University of Barcelona compared 154 genomes across 21 animal groups to reconstruct the genetic changes behind 11 separate transitions from water to land over the past 487 million years. The transitions happened in three major waves. Arthropods went first. Land snails came last. The most revealing finding was convergence: separate evolutionary lineages, the family trees of entirely different animal groups, that had been separated for more than 500 million years independently evolved similar genetic solutions to the same problems, particularly managing water and salt balance, the fundamental challenge of life outside the ocean. Semi-terrestrial species, the small invertebrates that still depend on moist soil, shared the most adaptations. Fully terrestrial lineages like insects and vertebrates took more divergent paths, each evolving its own innovations. The study was published in Nature in November 2025 and resurfaced this week through The Conversation.

Ocean species are vanishing before scientists can identify them. An international team led by the University of Göttingen and the Leibniz Institute for Biodiversity Change Analysis has launched EuroWorm, a project to build the first comprehensive open-access genomic database of European marine annelids, the segmented worms found across nearly all ocean environments. These animals mix sediments, recycle nutrients, indicate pollution levels, and support marine food webs. The project will collect specimens from European locations where many species were originally described, identify them by physical form, photograph them at high resolution, and analyse them using advanced genomic tools. The database will be freely accessible worldwide, with the explicit goal of accelerating species discovery before extinction outpaces science. “We hope to accelerate the discovery of new species and biodiversity research worldwide, and thus counteract the ‘silent extinction’ of marine species,” said project leader Dr Jenna Moore.

An Arctic blast turned the Gulf of Mexico bright blue. In late January and early February, two winter storms drove Arctic air across Florida, dropping temperatures below freezing in parts of the state and chilling the shallow waters off the west coast. As the ocean cooled, denser cold water flowed offshore, stirring up calcium carbonate mud, the accumulated remains of marine organisms, from the West Florida Shelf. NASA satellites captured the transformation: deep azure waters turned a vivid pale blue across a wide area. Landsat 9 imagery revealed “hammerhead” eddies along the shelf slope, curling patterns formed as narrow streams of cold, sediment-laden water met the slower-flowing Gulf. The same fluid dynamics appear in dust storms on Mars. The event is not only visually striking. Carbonate sediment suspensions affect the ocean’s carbon cycle. These resuspension events usually happen during hurricanes. Scientists know far less about how winter cold fronts produce similar effects, and the difference matters for understanding local carbon sequestration, the process by which carbon gets locked into deep ocean storage.

Hard Truth From The Sea

This week, delegates in New York debated the procedural architecture of a treaty designed to protect two thirds of the ocean. They discussed committee structures and funding mechanisms while the multilateral system the treaty depends on faces its most serious challenge in decades. The treaty exists because more than 85 countries agreed it was necessary. Whether it delivers depends on whether that consensus survives contact with the institutions, competing interests, and geopolitical realities that have historically made high seas governance a promise rather than a practice.

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See you next week.

- Luke