(This article by Paul Greenberg was originally published July 8 by Civil Eats and is reposted here with permission.)
Asian carp have now invaded much of the Mississippi basin, and they are threatening to enter the Great Lakes watersheds. But it was actually American catfish farmers and wastewater treatment facilities that introduced them to America. Initially it was hoped that Asian carp would help control pests and eat algae, which they do. But they also eat a large portion of the aquatic food web, and they have escaped beyond the sites of their initial stocking. (Note: They’re also edible.) 7. Mussels contain as much or more Omega-3 fatty acids than most fish, but most are also imported. Fish do not really make Omega-3s; micro-algae do. Fish only concentrate Omega-3s from what they eat, much the same way they concentrate toxins such as PCBs and mercury. Because mussels live on micro-algae they filter from the water, they contain high levels of Omega-3s — as much as canned tuna. Unfortunately, more than 90 percent of the mussels we eat in the U.S. come from Canada and New Zealand. 8. A large portion of the wild seafood we import comes to us illegally. Illegal, unreported and unregulated (IUU) fishing accounts for a large portion of the global catch. A recent study in the journal Marine Policy found that as much as 30 percent of the wild fish the U.S. imports comes to us illegally, e.g., it’s outside any management system whatsoever. 9. Most tuna consumed in the U.S. are imported and often caught with the aid of a controversial technique called “Floating Aggregating Devices.” Most tuna live in open, “blue” water with very little structure or shade and are therefore attracted to any kind of structure they come across. In nature, this may be marine debris or rafts of sea grass. Recently, however, fishermen have figured out that anything thrown into the water will attract tuna in large numbers. These Floating Aggregating Devices, or FADs, draw in tuna from far away and are often seen as skewing the dynamics of the ocean because they make these large, Pelagic fish such easy prey. 10. The U.S. exports as much salmon as it imports. Much of the wild salmon caught in Alaska is exported. Meanwhile, most of the salmon Americans eat is farmed and imported, mostly from Chile. Salmon are not native to Chile or to anywhere in the southern hemisphere and, in some instances, are considered an invasive species. But it’s not just wild salmon we export. Overall, we send abroad about 3 billion pounds of mostly wild seafood every year — about a third of the total American Catch.