The National Museum of Natural History's Sant Ocean Hall last week hosted the "Real Cost Cafe," an interactive performance about sustainable seafood. The child-friendly program originated at California's Monterey Bay Aquarium, and was adapted by Smithsonian's Discovery Theater. Three segments assessed the environmental issues at stake for a different kind of fish, ultimately tallying the fish's "real cost" to marine ecosystems and to human health.
I knew little about the subject prior to seeing the performance, but Rachel Crayfish and Bubba (the show's hosts, who were dressed in chef's hats and fishing gear) taught me about the sustainability issues at stake for some of the United States' favorite seafood: orange roughy, shrimp and salmon.
What is "sustainable" seafood? NMNH fish biologist Carole Baldwin—who has written a cookbook titled One Fish, Two Fish, Crawfish, Bluefish —sustainable seafood includes fish and shellfish harvested in a way that doesn't threaten the future of the particular species. The four primary factors that pose such a threat are "bycatch" (marine life that gets caught in fishing equipment by accident), overfishing, habitat loss and pollution.
Orange Roughy: This white fish, also known as the "slimehead," matures remarkably late in life, around age 20. These fish can live as long as 100 years, so you might be eating a fish that's older than your grandmother! Unfortunately, many young orange roughy that are caught have not yet had a chance to reproduce, making the species particularly susceptible to overfishing. According to the handy Monterey Bay Aquarium Seafood Watch card Bubba handed out at the performance, orange roughy is on the list of fish to avoid. This is not only due to overfishing, but also the harmful contaminants such as mercury these fish can contain. Pacific halibut is a much safer choice, and has a fairly comparable taste, at least according to our pals Rachel and Bubba.
Shrimp: One shrimp looks just like the next to me, but apparently not all are created equal when it comes to sustainability. The shrimp industry is one big contributor to the bycatch problem, often throwing away two pounds of unwanted marine species for every pound of shrimp caught. Shrimp farms are less affected by bycatch than the wild-caught shrimp industry is, but building shrimp farms often requires the destruction of rich marine ecosystems like mangrove forests. What's the lesser of the evils? Rachel and Bubba say that the United States and Canada have fairly strict regulations for shrimp farms that limit environmental destruction. U.S. or Canada-farmed shrimp make the "green" list for the best seafood choices on my Seafood Watch card.
Salmon: I was already aware that eating farmed salmon was a no-no, but I wasn't exactly sure why. As it turns out, farmed salmon can have higher levels of contaminants in their systems due to their diets. Furthermore, to my surprise, several different species are often sold as salmon, and some are better for you than others. Alaska wild salmon seems to be the most sustainable option, with Washington wild salmon coming in second.
Sometimes, says Rachel Crayfish, the "real cost" of seafood can be hard to swallow. Who's going to pay this "seafood bill," she and Bubba ask? The next generation, of course, some of whom were sitting, wide-eyed, with me in the Sant Ocean Hall on Saturday.