How to Choose Sustainable Seafood

How to Choose Sustainable Seafood Without a PhD

Buying seafood the right way takes effort. Grocery stores hang signs promising sustainable practices, sometimes directly above products every major seafood guide says to avoid. In the United States, “organic” has a legal definition backed by regulation. “Sustainable” has none, so a store can use it freely.

Dr. David Shiffman wrote Why Sustainable Seafood Matters to close that gap. On the book tour for Why Sharks Matter, which took him to seven countries and even Antarctica, audiences kept asking the same thing: if unsustainable fishing is the biggest threat to sharks, what should I buy? The resources available were either too basic to help or too technical for anyone without a fisheries science degree. His new book sits in the middle.

The biggest threat to ocean life

Climate change, plastic pollution, and oil spills all harm the ocean. David’s students are often surprised to learn that unsustainable fishing practices cause the most damage to marine biodiversity, through overfishing, bycatch, and habitat destruction. That affects fish, sharks, seabirds, sea turtles, and marine mammals.

The Grand Banks cod collapse off Newfoundland shows what’s at stake. Cod there once seemed endless, and the stocks helped draw European powers to North America. New fishing technology removed so many fish that too few remained to rebuild the population. Warning signs were dismissed, the fishery closed in the 1990s, and entire communities lost their way of life. Three decades on, recovery is only beginning. David draws three lessons: follow the data, remember that ocean harm reaches the people who depend on it, and get management right the first time.

Overfishing, overfished, and fully fished

Overfishing is an action: catching fish faster than the population can replace them. Overfished is a state: the population has dropped too low. A stock can have one, both, or neither. Neither is the goal.

This distinction matters because the UN Food and Agriculture Organization’s global fisheries report is often misquoted. About a third of global stocks are overfished. Most of the rest are fully fished, meaning harvested at appropriate levels. Some critics combine the two figures and claim nearly every fishery is in trouble. Fully fished is the target, so merging it with overfished creates a misleading picture.

What seafood labels actually tell you

Dolphin safe. Tuna fleets once found schools by spotting feeding dolphins, then set purse seine nets around them, killing the dolphins. Dolphin safe means fishers didn’t use that method. For tuna caught with almost no bycatch, look for pole-and-line caught, where crews land fish one at a time with rods.

MSC certified. The Marine Stewardship Council’s blue fish label shows up at major retailers worldwide. Fisheries are assessed against a science-based standard developed with hundreds of experts, and every certified fishery has a free public report. David worked on MSC’s research team studying bycatch of endangered, threatened, and protected species, and found the organization even more rigorous than he expected. Safeguards stop fisheries from hiring a friendlier assessor.

Farmed seafood. The Aquaculture Stewardship Council applies a similar standard to fish farms. Best Aquaculture Practices (BAP) is less rigorous and still much better than nothing. David’s rule of thumb: doing it right costs more, so producers who do it right advertise it. A vague source usually signals the worse option.

Bycatch has solutions

North Atlantic right whales are critically endangered, with roughly 70 breeding females left. They get tangled in the vertical lines connecting lobster traps to surface buoys, and the Gulf of Maine holds over a million of those lines. That bycatch put Gulf of Maine lobster on Seafood Watch’s red list and led MSC to withdraw its certification.

Two fixes exist. Weak rope holds during normal hauling and snaps when a whale swims through. On-demand ropeless gear keeps traps on the seafloor until the boat sends a signal that inflates a lift bag and raises them. Grants help cover costs, and many fishing communities are already testing it.

Sea turtles show what success looks like. Turtle excluder devices work as a weighted trapdoor sewn into shrimp nets. Shrimp stay in, turtles get pushed out, and shrimp catch barely changes. A recent requirement extended them to skimmer trawl boats over 40 feet in Louisiana.

Trawling and marine protected areas

Bottom trawling in sensitive habitats is extremely destructive, leaving scars on the seafloor visible from space. David supports keeping it out of those places and out of marine protected areas. He doesn’t support a blanket global ban, because trawling supplies roughly a quarter of the world’s seafood and some sandy or muddy bottoms can be trawled responsibly. MSC-certified and Seafood Watch green-rated bottom trawl fisheries exist.

Well-designed, well-managed marine protected areas hold more fish, bigger fish, and more species than similar unprotected areas. Poorly designed ones deliver little, including some that still allow industrial trawling and a few built to protect species that never lived there.

What you can realistically do

Expect to need more detail than you think. Seafood Watch rates tuna by species, origin country, and gear type, and packaging rarely shows all three. Check the retailer’s website, use the Seafood Watch app, and ask staff politely. When David’s students assess random products at local grocery stores, nearly all find sustainable options alongside plenty that aren’t.

One shopper changes little alone. Millions following the same guides push fisheries to improve, and that has already happened. Doing a little better buys time to fix the ocean’s other problems.

Why Sustainable Seafood Matters is available for preorder from Johns Hopkins University Press, releasing November 17. Follow David at @WhySharksMatter.

Takeaways

• Unsustainable fishing is the leading threat to marine biodiversity.
• “Sustainable” on a seafood label has no legal definition.
• Fully fished is the management goal. Overfished stocks signal a problem.
• Dolphin safe covers one fishing method. Pole-and-line tuna is the low-bycatch choice.
• MSC and ASC are the most rigorous labels, and BAP still beats no label.
• Weak rope, ropeless gear, and turtle excluder devices prove bycatch can be solved.
• Bottom trawling belongs out of sensitive habitats and marine protected areas.
• Use Seafood Watch or Ocean Wise when packaging lacks detail, and ask staff kindly.
• Collective consumer pressure has already pushed fisheries to improve.