Plastic Is Still the Ocean's #1 Villain, with Dr. Judith Weis
Release Date: 09/28/2026
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...
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Whales Are Sprinters: What a Blue Whale's Heart Does When It Lunge Feeds
How To Protect The Ocean
What happens to the heart of the largest animal on Earth when it charges into a swarm of krill? Dr. Ashley Blawas, a postdoctoral scholar in Jeremy Goldbogen's lab at Stanford's Hopkins Marine Station, joins Andrew to unpack new research published in PNAS that measured the heart rates of lunge-feeding blue whales and humpback whales using suction-cup ECG tags. Ashley explains the three phases of lunge feeding (accelerate, engulf, filter) and why these giants behave a lot like human sprinters. Their heart rates stay high after each lunge, then gradually recover while they glide and filter,...
info_outlinePlastic keeps getting made, it never goes away, and almost none of it gets recycled. Dr. Judith Weis, Professor Emerita at Rutgers University Newark and Andrew's very first guest on this podcast more than 2,000 episodes ago, returns for her fourth appearance to talk about the second edition of her book, Marine Pollution: What Everyone Needs to Know.
Judith walks through every major category of marine pollution: nutrients, metals, oil, pesticides, marine debris, pharmaceuticals, ocean acidification, and one category that surprises most people, biological pollution. She explains why microplastics earned a brand new chapter, why they're so hard to study when they're in every lab and every body, and what Canada's legal fight over listing plastic as toxic means for regulation.
There's good news too. Judith grew up near a Hudson River full of raw sewage. After the Clean Water Act and new treatment plants, New Yorkers now walk the waterfront, the water is swimmable in dry weather, and humpback whales feed in New York Harbor. Andrew and Judith ask what that comeback can and can't teach us about plastic, and what you can do today.
Takeaways:
- Every major type of marine pollution comes down to three questions: where it comes from, what it does, and what we can do about it.
- Judith calls plastic the number one villain in marine pollution today because production keeps rising and recycling doesn't work at scale.
- Microplastics are 5 mm or smaller, mostly invisible, and carry chemicals both inside them and stuck to their surfaces.
- They're so widespread that researchers struggle to find microplastic-free controls for experiments.
- Canada listed plastic manufactured items as toxic under CEPA, banned six single-use categories, and saw that listing upheld on appeal.
- Large tanker spills have become far less common, with double hulls part of the reason.
- Sewage treatment after the Clean Water Act transformed the Hudson River and New York Harbor, and whales are back.
- Pharmaceuticals and hormones pass through treatment plants and change fish behavior and biology.
- Invasive species count as biological pollution, and unlike chemicals, they reproduce.
- Beach cleanups, local environmental chapters, and cutting your own plastic use are practical places to start.
Buy the book: https://global.oup.com/academic/product/marine-pollution-9780197753811?cc=ca&lang=en&
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