The story of the hidden cost of calamari begins along the shores of the Sea of Japan. This is one of the most heavily contested and poorly monitored patches of ocean on the planet, framed by four countries (South Korea, North Korea, Japan and Russia) all of whom stake overlapping and disputed territorial claims to its waters. It is here that a mysterious and grizzly phenomenon has baffled Japanese authorities for years. Along the length of Japan’s west coast, hundreds of North Korean fishing vessels have been washing up on the shores, their only cargo the decomposing bodies of their crews.

New revelations have come to light that may explain this macabre phenomenon. An extensive investigation by NBC News and The Outlaw Ocean Project has revealed the largest fleet of illegal fishing boats ever documented and the role this previously invisible flotilla may be playing in the dead bodies washing ashore in Japan, as well as a precipitous decline in the squid stock.

The grim discoveries of these so-called ‘Ghost Ships’ is disturbingly common in Japan. As many as 165 of these vessels were found in 2019, with the Japanese Coast Guard reporting the bodies of 50 North Koreans washing up in the same period, according to the investigation. The ships are largely dilapidated, wooden vessels with little to no facilities or shelter for those unfortunate enough to serve as their crew. Autopsies of the bodies revealed the crews to be overwhelmingly male, most of whom died through starvation, dehydration or hypothermia. Yet the mystery of why so many of these doomed vessels are washing up, sometimes carried for months by wind, current and tide to Japan’s shores, has long been unanswered.

The most likely scenario is that these are desperately poor fishermen from Kim Jong Un’s hermit state, who find themselves under ever greater pressure from Pyongyang to catch larger quantities of what is already a stock under strain. Desperation has driven them to explore and exploit waters far beyond North Korea’s Exclusive Economic Zone (EEZ). But pressure at the hands of the government is not thought to be the sole reason for these dangerous forays into foreign waters.

The international investigation team included Global Fishing Watch, a non-profit organisation that specialises in the use of satellite technology and AI to track illegal activities on the high seas. They were able to detect a previously invisible fleet of more than 700 Chinese vessels thanks to satellite technology capable of detecting the extremely bright lights used by squid fishermen at night to coax their prey closer to the surface. This armada had until recently been operating in the shadows owing to their captains routinely turning off their Automatic Identification System (AIS) transponders, rendering them invisible to authorities on land.

The Outlaw Ocean team documented the Chinese fleet crossing into North Korean waters under the cover of darkness, travelling with their AIS transponders off merely 100 miles from shore. These vessels are operating in direct violation of the 2017 sanctions imposed by the UN Security Council (of which China is a member) in response to Pyongyang’s nuclear tests. Those sanctions forbid all fishing by foreign vessels in North Korean waters, in a bid to stifle a previously vital source of revenue in the form of fishing rights sold to foreign operators.

The Chinese vessels are notoriously aggressive and known to intimidate local fishermen around the wider region. In North Korean waters, it appears that they have out-muscled local fishermen, who cannot compete with these larger ships, which often exceed a gross tonnage of 200 tonnes; forcing them to take further out to sea, encroaching into the EEZs of Japan, South Korea and Russia in search of an adequate catch.

All too often, their vessels are unfit for such voyages, increasingly crewed by inexperienced mariners; often soldiers haphazardly retrained as fishermen. Many crews have fallen victim to the harsh conditions in these waters, battered by heavy storms, or succumbing to exposure. Others have had their fate sealed by simple engine failures, or running out of fuel, suffering a tragically slow death as their battered wooden ships drift for months on the currents.

The impact of the illegal Chinese fleet has been severe, perhaps nowhere more so than in the dozens of widows villages that dot the North Korean coast, a macabre reference to the communities in which men have gone to sea and never returned.

The discovery of such an enormous illegal fleet highlights the significant shortcomings in terms of international law and its enforcement across the world’s oceans. The myriad loopholes and grey areas in legal structures such as the UN Convention of the Law of the Sea coupled with a lack of enforcement in the case of squid fishing, and a lack of transparency in the international supply chain leaves consumers largely in the dark about the hidden cost of their food, beyond that printed on the menu. It highlights the need for all of us to ask the sometimes uncomfortable questions of where our seafood is from, how it is caught, and perhaps most of all, at whose expense?