I have often wondered why it is wrong to kill a fox or a seal, but all right to kill a fish.
A fox will kill a lot more birds in a hen house than it really needs, just to get one bird. It will also kill young lambs. The seal has no good points, it just eats fish.
Seals congregate at river mouths to catch the fish as they come in to spawn, and the young ones as they try to get out, meaning there will be less fish from that river as time goes on.
What about the fish? Well, the fish don't harm man in any way.
Some years ago I read in a magazine there were more people going fishing at weekends than there were going to football matches.