For years the grisly phenomenon mystified Japanese police, whose best guess was that climate change pushed the squid population farther from North Korea, driving the country’s desperate fishermen dangerous distances from shore, where they become stranded and die from exposure.
But an NBC News investigation, based on new satellite data, has revealed what marine researchers now say is a more likely explanation: China is sending a previously invisible armada of industrial boats to illegally fish in North Korean waters, violently displacing smaller North Korean boats and spearheading a decline in once-abundant squid stocks of more than 70 percent.