As Taras Grescoe pointed out in Bottomfeeder and Paul Greenberg most recently outlined in Four Fish, we eat too many of a very few species of wild fish – mostly the ones that are higher on the food chain. Continuing in this vein will cause the eventual decimation of our oceans.
What can you do about it?
Branch out and try something new. Eat bait, or smaller fish, like anchovies, sardines, and small Spanish mackerel. These fish are more sustainable, more plentiful, more resilient, and healthier for you than the larger predators.