Nature's Kidneys: How Coastal Wetlands Stop Ocean Pollution
Release Date: 09/15/2026
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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...
info_outline
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_outlineGreen water. A smell that won't go away. Sometimes, dead fish washing up on shore. That's what too much nitrogen does to a coastline, and it's easy to hear stories like this and feel like the ocean is just losing. This episode is the opposite of that.
Here's what most people don't know: a healthy stretch of marsh or mangrove can pull nitrogen straight out of the water before it ever becomes a problem. A single restored 100-acre wetland cut nearby ammonia by 62 percent and total nitrogen by 37 percent, and saved local water systems about $17,000 a year, all within three years. Then there's Tampa Bay: a bay written off as dead in the 1970s that came back so completely it now underpins roughly 1 in 5 jobs in the region, because people regulated pollution and rebuilt the habitat doing the filtering.
This episode walks through the real mechanism (how wetland soil locks nitrogen away for centuries), the Tampa Bay turnaround in full, and the Mississippi River's springtime dead zone, then lands on one thing you can actually do this season.
Takeaways:
- Excess nitrogen, not nitrogen itself, is what causes algal blooms, red tide, and dead zones along the coast.
- Healthy coastal wetlands (marshes, mangroves, seagrass) pull nitrogen out of the water before it reaches a bay, and lock it away in oxygen-starved mud for centuries.
- A single restored 100-acre wetland cut nearby ammonia by 62% and total nitrogen by 37% within three years, saving local water systems about $17,000 a year (Skidmore and Karwowski, Journal of AERE).
- Tampa Bay went from a 1970s pollution poster child to a bay where seagrass nearly doubled (21,600 to over 40,000 acres) after regulation and habitat restoration, and now supports roughly 1 in 5 regional jobs.
- Cutting back on synthetic lawn fertilizer, or switching to a slow-release or organic option, reduces the same runoff that overwhelms a wetland's filtering capacity.
Support Independent Podcasts: https://www.speakupforblue.com/patreon
Need help with your ocean non-profit, company, or project? Get the help you need with Pisces Oceans Inc.: https://www.piscesoceans.ca
Connect with Speak Up For Blue
Website: https://bit.ly/3fOF3Wf
Instagram: https://bit.ly/3rIaJSG
TikTok: https://www.tiktok.com/@speakupforblue
Twitter: https://bit.ly/3rHZxpc
YouTube: www.speakupforblue.com/youtube