For years, wildlife organizations and international agencies have been warning that overfishing is rapidly depleting ocean fish stocks. Because the global fishing fleet is estimated to be three times larger than our oceans can sustain, the populations of big fish—tuna, swordfish, cod, marlin, and others—have declined by 90 percent since 1950. If this trend continues, populations of all food-specific species could theoretically collapse by 2048. And that’s where fish farming comes in. Though the downsides of traditionally farmed fish are numerous and well-documented—disease, environmental damage, nutritional degradation, habitat destruction, antibiotic use, and forage fish depletion among them—some innovative aquaculture models are now carving out new, non-destructive means of farming fish, and winning over longtime skeptics.
Attention shoppers: The fresh Chilean sea bass in the seafood case—that filet of Marine Stewardship Council-certified “best choice” fish—might not be Chilean. In fact, it may not even be sea bass.
Earlier this year,biologist Peter Marko visited ten different supermarkets and bought 36 filets of certified sustainable Chilean sea bass. In a letter published last week in Current Biology, Marko explains how he extracted mitochondrial DNA samples from the fish and matched them against the distinct genetic fingerprints of the certified population. How did the genes in the retail samples stack up against the genetic material collectedfrom a certified batch of fish in the sea? Thirteen percent of the sea bass appeared to be from another, uncertified stock, and another 8 percent were an entirely different species of fish altogether. If these eco-certified fish were Dior handbags, one in every 12 would probably be a knockoff.