Reading up about food recalls and mercury can make one a little paranoid. Fish often get a bad rap because of the concern about mercury levels for pregnant women and children. The Orlando Sentinel has a nice story weighing the costs and benefits of eating fish. On the whole, fish is good for you!
The salmon story illustrates this nicely. Using data from the EPA and elsewhere, Mozaffarian and Rimm estimated that PCB intake from eating farmed salmon twice a week for 70 years would cause an extra six cases of cancer per 100,000 people, while eating wild salmon would cause two extra cases. Yet eating either would prevent at least 7,000 deaths from heart disease. Even if the hazard was 10 times greater and the benefit one-tenth the size, the scales would still favor eating fish.