Millimeters That Matter: The Sea Level Rise Threshold Coastal Wetlands Can't Survive
Release Date: 09/17/2026
What Your Farmed Salmon Ate: Inside a Five-Year Fishmeal Investigation
How To Protect The Ocean
More than half the seafood eaten on Earth now comes from fish farms, and most of those farmed fish are raised on fishmeal made from wild-caught fish. Maya Martin, deputy editor at The Outlaw Ocean Project, joins Andrew Lewin to unpack Food for Feed, a five-year investigation that traced fishmeal from the ships that catch it, through the plants that grind it, to the farmed fish on your plate. Maya explains how forage fish like sardinella and anchoveta are pulled from waters off West Africa, Peru and Southeast Asia, often from stocks that are already overexploited and from communities that...
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How to Read the Seafood Counter Like a Marine Biologist
How To Protect The Ocean
Picture a big sign over the seafood counter promising sustainable fishing, with a fish every independent guide says to avoid sitting on ice right below it. In most countries nobody broke a rule, because the word "sustainable" on seafood has no legal definition. In this final episode of our sustainable seafood week, Andrew Lewin walks you through how to see past that sign and choose seafood you can feel good about. You'll learn how to use the eco-labels and seafood guides that have already done the research for you, including the Marine Stewardship Council's blue tick for wild seafood, the...
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Is Bottom Trawling Always Bad? It Depends Where
How To Protect The Ocean
Off the south coast of England, about 100 kilometres out, sits Haig Fras, a granite reef covered in jewel anemones and cup corals. For years it was protected on paper, yet heavy fishing gear could still drag across it. In March 2024, that finally changed. In this episode, Andrew Lewin explains why where we fish matters as much as how much we fish, and what it takes to turn a line on a map into real protection. Andrew breaks down the difference between midwater and bottom trawls and puts the damage shown in the recent Ocean documentary into context. Bottom trawling lands about a quarter of the...
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The Trapdoor That Saves Sea Turtles From Shrimp Nets
How To Protect The Ocean
A Kemp’s ridley sea turtle, the most endangered sea turtle on Earth, gets swept into a shrimp trawl. It hits a metal grid, slides out through a flap in the net, and swims away. That small trapdoor, the turtle excluder device, is one of the biggest success stories in fisheries management, and in late August 2026 a US federal appeals court upheld the rule extending it to skimmer trawl boats 40 feet and longer. In this episode, marine biologist Andrew Lewin walks through the bycatch fixes that are working and the fights still underway. You’ll hear why North Atlantic right whales get tangled...
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The Cod Came Back: What a Fishery Collapse Teaches Us About Overfishing
How To Protect The Ocean
Five centuries ago, explorers off Newfoundland described cod so plentiful that a weighted basket lowered into the sea came back full. By July 2, 1992, so few remained that Canada shut the northern cod fishery overnight. About 30,000 people lost their work in what became the largest single layoff in Canadian history. In this first episode of a week-long sustainable seafood series, Andrew tells the story of how the collapse happened and how slowly the cod came back. Andrew then breaks down the words that cause the most confusion in fisheries headlines: overfishing, overfished, depleted, and...
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How to Choose Sustainable Seafood
How To Protect The Ocean
You want to eat seafood the right way. Then you hit the seafood counter and face a wall of labels, a sign promising “sustainable practices,” and an employee who has no idea where the tuna came from. Add documentaries like Seaspiracy telling you to quit fish entirely, and it’s tempting to give up and buy whatever looks good. Unsustainable fishing is the biggest threat to marine biodiversity, so those choices carry real weight. In this episode, Andrew’s good friend Dr. David Shiffman joins the show to talk about his new book, Why Sustainable Seafood Matters. David spent two years on the...
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Slow Down for Whales: How Global Shipping Learned to Share the Ocean
How To Protect The Ocean
Blue whales can’t dodge ships. When scientists tracked blue whales alongside cargo ships off Southern California, the whales responded in just over half the encounters, and every response was the same: a slow, shallow dive. Not once did a whale move sideways out of the ship’s path. Models suggest ships kill around 18 blue whales a year off the U.S. West Coast, nearly eight times what the population can lose and still recover. The good news is in the data. Most blue whale strike deaths happen in a small slice of ocean, and that’s where ports, air quality agencies, marine sanctuaries, and...
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When Whale Food Moves: Climate Change, Crab Traps, and Pop-Up Gear
How To Protect The Ocean
In 2014, a patch of unusually warm water nicknamed "the blob" settled off the west coast of North America. The cold, food-rich water that normally stretches far offshore shrank into a narrow strip along the coast, and hungry humpback whales followed their food straight into the waters where Dungeness crabbers had set thousands of traps, each tied to a vertical rope. Entanglements jumped from about 10 a year to 53 in 2015 and 55 in 2016. In this episode, Andrew traces the line from warmer water to a specific whale in a specific rope. You'll learn why lunge-feeding whales depend on dense patches...
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The Whale Heart That Beats Twice a Minute
How To Protect The Ocean
Fill your hands with cold water, hold your breath, and press your face in. Your heart slows within seconds. That reflex lives in every whale in the ocean too, and in a blue whale it is pushed so far that the largest heart on Earth can drop to two beats a minute on a deep dive. In this episode, Andrew walks through the first heart rate recording from a wild blue whale, led by Jeremy Goldbogen's team at Stanford, and a study by Terrie Williams of UC Santa Cruz that tracked narwhals fleeing after release from nets in East Greenland. The narwhals swam as hard as they could while their hearts fell...
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The Biggest Mouthful: How Blue Whales Eat and Why Krill Matters
How To Protect The Ocean
A blue whale can swallow a volume of water bigger than its own body in a single gulp. That move, called lunge feeding, is one of the most extreme feats in the animal kingdom, and it only pays off when krill is packed into thick, dense swarms. In a thin patch, a blue whale gets back about six times the energy it spent. In a dense swarm, it gets back more than 200 times. In this first episode of the Age of Giants series, Andrew breaks down how rorqual whales feed, then follows the krill. In 2025, the Antarctic krill fishery hit its 620,000 tonne precautionary limit for the first time and closed...
info_outlineSea level rise. It's a phrase everyone's supposed to be afraid of, and almost nobody can picture. A couple of millimeters a year sounds too small to matter, until you find out coastal wetlands have an exact, measured speed limit for how fast they can keep up, and the ocean is closing in on it.
Marshes and mangroves have kept pace with a rising sea for thousands of years by building their own soil upward, layer by layer, as plants grow, die, and get buried in place. That strategy has a hard limit. Peer-reviewed research puts it at roughly 6.1 millimeters of sea level rise a year, the point past which soil simply can't build fast enough. NASA's own sea level data shows the global rate has already gone from about 2 millimeters a year in the early 1990s to roughly 4.5 millimeters a year today, nearly doubling in three decades and closing that gap fast.
There's a second strategy, and it's already working in real places. When a marsh can't out-build the tide, it can move inland instead, if there's room. Maryland's Blackwater National Wildlife Refuge has lost more than 5,000 acres of marsh, nearly half its historic wetland, and faces up to three feet of sea level rise in the Chesapeake by 2100. Its 2013 Blackwater 2100 strategy uses conservation easements to pay landowners to keep migration corridors open, and it's already protected more than 3,000 acres along the Nanticoke River and Coursey Creek. This episode connects back to Monday's interview with Dr. Adam Langley and lands on what coastal communities can actually do about it.
Takeaways:
- Marshes and mangroves survive sea level rise by building soil upward, but that strategy has a hard limit: peer-reviewed research (Saintilan et al., 2020, Science) puts it at roughly 6.1 millimeters of sea level rise a year.
- NASA's sea level data shows the global rate has already climbed from roughly 2 millimeters a year in the early 1990s to about 4.5 millimeters a year today, nearly doubling in three decades.
- When building up stops working, marshes and mangroves have a second option: shifting inland, provided there's open land behind them to move into.
- Maryland's Blackwater National Wildlife Refuge has already lost more than 5,000 acres of marsh, nearly half its historic wetland, and its 2013 "Blackwater 2100" strategy uses conservation easements to keep migration corridors open along the Nanticoke River and Coursey Creek.
- The plan is working but unfinished: roughly 812 acres are protected along Coursey Creek and 2,300 along the Nanticoke, with about 5,000 acres still unprotected.
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