If you like fish you should be aware that not all fish are good to eat. Well, they may be tasty but they might also be over fished. For example, only wild Alaskan Salmon should be considered safe to eat.

Alaska salmon populations are healthy and abundant and their spawning streams are pristine and unobstructed by dams. Wild Alaskan salmon are caught using purse seines, gillnets and hook-and-line gear, all of which have minimal impact on seafloor habitats or the surrounding marine ecosystem. The Alaska salmon fishery is also well managed.

Farmed Salmon is bad.

The U.S. market is flooded with inexpensive farmed salmon from Chile, Canada and Norway. Salmon is also farmed to a limited extent in the United States. Raising salmon in net pens releases fish waste into the water and can spread disease and parasites to wild salmon. Also, domesticated Atlantic salmon that escape from farms in the Atlantic can breed with and compete for precious natural resources with endangered native wild salmon. These environmental concerns have led some sectors of the aquaculture industry to improve farming practices. Progress has been made at reducing the amount of waste generated per pound of fish, decreasing the use of antibiotics and pesticides, and building stronger pens to prevent escapes. Despite these improvements, the environmental impact of salmon farming is still increasing, because production of farmed salmon has risen more than 400% in the last decade. In the market, there is currently no way to tell which salmon are coming from more-sustainable farms.

Some farmed fish are good though, the Monterey Bay Aquarium has a extensive Seafood Watch website on what fish is good to buy and what fish are not.