How many states are there with access to pacific waters that could potentially have thousands of unregistered fishing vessels and whom a poster would be uncomfortable naming explicitly for fear of backlash?
It's a logical guess that the only country that could have thousands of unregistered ships would be china, one of the worlds leading industrial powers with a large pacific coastline. It's xenophobic speculation that china does in fact have these ships and specifically are the cause of this population collapsing.
Portuguese fisherman were the big thing off the coast of Canada. Definitely not unique to China, although they seem to use fishing boats as a political tool like Russia uses little green men. But that's closer to their shores.
China has been the subject of multiple high-profile news stories (and popular HN threads) about overfishing. They’re also the standard xenophobic bugbear on HN.