Nature
PUBLISHED
The mutilated carcasses of 300 thresher sharks have been found dumped on the side of the road in the Mexican state of Michoacan, 240 kilometers (150 miles) from the sea.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.In what is now thought to be a cartel-related theft – of the truck carrying the sharks, not of the sharks themselves – the frozen carcasses were found gutted, finned, and dumped in the township of Yurécuaro, an area known for local drug cartel violence and crime.
When residents came across the carcasses – around 250 in bags and 50 uncovered – scattered along the La Piedad-Guadalajara highway, there were fears they could be human remains, according to Mexican news website Marquesina. Local authorities were immediately notified, and the sharks were collected and taken away.
According to a statement from the Federal Attorney for Environmental Protection (PROFEPA), the sharks had been legally fished in the states of Sonora and Sinaloa, in the north, and the frozen carcasses were being taken by truck to Mexico City when cartel thieves likely hijacked the truck and dumped its cargo.
Thresher sharks are not a protected species in Mexico, which means it is legal to fish them – and demand for threshers, in particular, is high. Their long pointy tails – used to whip about and stun prey – can reach the length of their entire body and are very lucrative in the shark trade. Their hides are also used for leather and oil from their livers is processed and used in vitamins.
However, the IUCN Red List lists all species of thresher as Vulnerable due to their declining populations. A combination of being a slow-growing species that only reaches maturity at between 8-14 years of age when they have small litters, and the high rate of mortality due to fisheries, both as a target and as bycatch, means they are depleting rapidly.
“This species is especially vulnerable to fisheries exploitation (target and by-catch) because its epipelagic habitat occurs within the range of many largely unregulated and under-reported gillnet and longline fisheries, in which it is readily caught,” the IUCN listing states.
Gillnets, of course, have come under a lot of fire recently due to the sad plight of the vaquita porpoise, which could go extinct in our lifetime as there are now fewer than 30 left. Attempts to save the smallest cetacean, which only lives in the Gulf of California, had to be abandoned after one died during a last-ditch effort to save them by moving them away from waters where they often end up caught in the nets as bycatch.
