Fish consumption is as unethical as red meat. Fishing involves killing the fish for no valid reason. Fish is an extremely concentrated source of protein, cholesterol, and heavy metals. The smaller the fish, the more likely you are to eat the intestines and fecal material along with the animal.
The bigger fish eat the smaller fish and accumulate all the metals. Fish particularly oily fish can concentrate toxins in their flesh. The heavy metal mercury is a grave concern and its presence makes fish unsuitable for human consumption. Salmon both farmed and to a lesser extent caught wild can contain worrisome levels of PCBs. Freshwater anglers are advised that their catch can contain various toxins, depending on the waters they come from. Species from polluted waters are another concern and it’s difficult to ensure or know the extent of water pollution. Children and pregnant or nursing women should particularly be careful against fish contamination.
Health Canada warns against consuming fresh Tuna more than once a month. There is just nothing worth getting from fish unless you have no other source of calories. Overall, eating fish is unnecessary and not worth taking all the risks besides being a result of violence against innocent animals.