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.

This is widely known, just not to you.

Calling names won't change that.

Japan's pacific coastline is twice as large as China's. Your logic here is extremely faulty.