Vegetarians/vegans do not eat fish! If you eat fish but no red meat or poultry, you are a pescatarian. Adventist pescatarians eat only fish with fins and scales.

Farm-Raised vs. Wild-Caught Fish
http://www.quickanddirtytips.com/health-fitness/healthy-eating/farm-raised-vs-wild-caught-fish

Mercury Toxicity, Kids & Fish Consumption
https://chriskresser.com/mercury-toxicity-kids-fish-consumption/?utm_source=twitter&utm_medium=share&utm_term=toxicity-kids-fish&utm_content=&utm_campaign=blog