We need a seafood diet for a small planet


In May 2003, I had the great honor of meeting the legendary Harvard scientist Dr. Edward O. Wilson. When I thanked him for signing our letter calling on the UN to institute a moratorium on longline fishing in the Pacific to prevent the extinction of the Pacific leatherback, his reply was, “It’s a no-brainer.”

Industrialized fishing fleets that will leave depauperate, unhealthy oceans for future generations are destroying marine biodiversity.

Industrial longline fishing boats on the high seas set 5 million baited hooks every day, more than 2 billion each year, to catch the great fish of the world—including swordfish, tuna, and sharks.

These fish are the lions and tigers of the sea—the top predators of the marine food chain, the keystone species that maintain and regulate the ocean’s food webs. We need to stop eating these species. A growing human population will continue to rely on the marine ecosystem for sources of protein.

If eating swordfish and tuna is out of the question, what marine animals can we eat? Different environmental organizations offer various answers to this difficult question, and some have issued seafood guides based on criteria including:

  • Health of the specific targeted fish population;
  • Management measures in place to maintain or improve the health of the target fish species;
  • “Bycatch” (collateral damage caused to other species) associated with fishing technology; and
  • Collateral damage caused by the technology to marine habitat (for instance, reef damage from trawl nets, and pollution from fish farms).

Research into these criteria for popular seafood choices is conducted and ranked with a recommendation as to whether a species is a best choice, a species to avoid, or somewhere in between.

I think two very important criteria have been left out of the equation: What role does the species play in the food chain, and is the species healthful for human consumption?

For example, some of these seafood guides don’t place some populations of swordfish, tuna, and shark in the “avoid” category. Yet these fish are currently on the FDA and EPA list of species that children and women who intend to reproduce shouldn’t eat because large fish at the top of the food chain concentrate mercury in their flesh. These same species are caught by industrial longline fishing, which has been identified as the primary cause for the decline of the critically endangered Pacific leatherback turtle, and the 90 percent decline in giant fish recently reported in Nature.

Twenty years ago, Francis Moore Lappé wrote Diet for a Small Planet, a book that sold three million copies and helped an entire generation understand the social and personal significance of our everyday food consumption habits. Lappé taught us that it takes ten pounds of grain to produce one pound of beef, and that if we eat lower on the food chain we can improve our own health as well as the health of our environment.

If we are going to co-exist with healthy ocean ecosystems, we need a “seafood diet for a small planet.”

The seafood guides represent the first attempts at moving seafood lovers in the right direction. But to date, no single list incorporates a holistic view that encourages consumers to eat lower on the seafood chain (for example, small fish and shellfish harvested by acceptable methods), avoid fish with high levels of toxins, and also recognize that our overall seafood consumption must be reduced.

As for not eating mercury-tainted swordfish, tuna, shark, and king mackerel? That’s a no-brainer.

Todd Steiner is a biologist and the director of Turtle Island Restoration Network (www.seaturtles.org), which works to preserve and restore marine biodiversity. He has been actively involved in many of the major fisheries issues of the past two decades, including tuna/dolphin purse seining, sea turtles/shrimp trawling, mercury in seafood, and the impacts of the growing longlining fleet on a number of target and bycatch species.

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