The report comes as the U.S. weighs regulatory changes that could result in more stringent enforcement of an existing law governing U.S. fisheries imports. Since Canada is the second-largest fish exporter to the U.S. after China, with $2.5 billion worth shipped per year, any regulatory revamp could be felt across the border. The document says 650,000 sea mammals are killed each year, while nearly all fish imported into the U.S. come from countries — including Canada — that fail to provide similar protections or don't meet American reporting guidelines.