Jul 24 (CNN) - For years, Japan's north coast had been the site of a macabre phenomena: fishing boats washing up on shore carrying the bodies of dead North Koreans, more than 1,000 kilometers from their homeland.
But the numbers in 2017 were unprecedented: More than 100 boats landed on the Japanese coast with 35 bodies on board. Only 66 boats had washed up the year prior.
No one was able to explain why so many of these so-called "ghost ships" ended up in Japan that year. One Japanese Coast Guard said it could be as simple as the weather. Others speculated that North Korea's aging fishing fleet was to blame.
More of these rickety boats have washed up on shore en masse since, though with fewer bodies. The mystery has puzzled authorities for years, but a study published Wednesday by international nonprofit Global Fishing Watch offers a new, compelling theory. It blames Chinese "dark fishing fleets."
The report's authors used various satellite technologies to analyze marine traffic in northeast Asia in 2017 and 2018 and found that hundreds of Chinese fishing vessels were sailing in waters off North Korea. The Chinese ships appeared to be fishing there illegally, pushing North Korea's own fleet, which is poorly equipped to travel long distances, further away from the North Korean coast and into Russian and Japanese waters.
