I think there is a difference in nutrition depending on the item in question. Take wild caught salmon versus farmed atlantic salmon. Wild caught has fed on animal life all it's existence while farmed salmon has been fed a diet based on grains, hence the multiple complaints around salmon pens polluting their local neighborhoods, and They won't have the same omega 3 fatty acids that salmon are prized for. Same goes for multiple sites of shrimp farms, they're fed an artificial pellet food stuff hardly natural. Also, a large number are set up in areas that have been cleared of mangrove forests which changes the eco system in many ways and sets up a dangerous labor chain while destroying the locals previous way of living. On the other hand, oyster farms (we have a tiny one on my son's property) and scallops all depend on nature and the sea around to provide for their nourishment which has been unchanged in eons. (until recent global warming which may force a change from the indigenous olympia oyster to the imported japanese olympic/pacific/ whatever local name you wish to put on it. Also, in some instances if you grow your own shrimp/copepodes/isopodes etc you can mess with nature in a "positive" way (for your fish) and pump them full of extra ingredients. The point is, oysters and scallop would be good where ever you find them but take care with fish and shrimp. Although fish may not live long enough for nutrition differences to make any difference.
