So now it's called anti-americanism when Canadians don't let Americans rob them blind?
The fish didn't belong to Canada. They were caught in U.S. waters or international waters.
The fish orginate in Canada. The Americans catch salmon left alone by the Canadians so that they'll return to spawn in Canadian waters. If the Americans continue to take the fish, the result will be no salmon for either the Canadians or Americans. This has already happened with Coho salmon.