When I was a kid, we learned in school about how we'd deal with the population explosion's need for more food by getting an increasing supply of our protein needs from the sea.
Now, as we all know, fish is expensive and scarce. Fisheries have collapsed. And, as the enclosed article shows, farmed fish, especially salmon, may be too dangerous to eat often:
"In some cases the levels of contaminants are so high that by EPA guidelines you shouldn't even have one serving a month it's more like one every five months in the case of some northern European farmed salmon. Researchers estimate that the risk of cancer from contaminants is about three times higher for farmed salmon compared to wild."