Floating like a macabre fence of buoys, some 300 decomposing endangered turtles were found by fishermen off the coast of Oaxaca, Mexico, on Tuesday, according to Reuters.
The olive ridley turtles, which are endangered, may have suffocated from being caught in the nets, died from swallowing fish hooks, or been poisoned by algae blooms. The cause of death is currently being investigated by the country’s environmental protection agency, known as PROFEPA, which plans to hold accountable parties liable if criminal or negligent intent is found.
It’s likely that wrongdoing will surface — nets in which the turtles were found are prohibited from use in the area because of the threat they pose to animals, according to CNN.
Take Action: Say No to Using Single-Use Plastics
Mexico has programs in place to protect sea turtles from injury, capture, and death, but this is the second mass death of turtles that has been found in the area in the past month, according to Reuters, suggesting lax enforcement.
The event also reflects a much deeper and ongoing crisis facing both turtles and other marine life around the world, and the global lack of serious maritime enforcement surrounding the issue.
Fishing bycatch — discarded fishing equipment like nets and hooks — poses a major threat to turtles and other large marine animals. Hundreds of thousands of loggerhead and leatherback turtles are killed by bycatch each year, according to the World Wildlife Foundation (WWF).
Turtles often die by swallowing fish hooks that then shred their insides, or get entangled in and immobilized by fishing nets.
Fishermen in the southern Mexican state of Oaxaca have found about 300 dead sea turtles entangled in fishing nets.
— BBC (@BBC) August 29, 2018
👉 https://t.co/SHfG4F422spic.twitter.com/G38icWCKIF
Read More: Why You Should Probably Never Eat Seafood Again
WWF also estimated that more than 300,000 whales, dolphins, and porpoises get killed by bycatch each year.
Despite laws and regulations that seek to mitigate bycatch harm, some turtle populations have plunged by 80% in less than 20 years.
That’s partly because many countries have trouble policing their waters, and large swaths of global ocean area are outside of national jurisdictions.
Mexico, in particular, has struggled to enforce environmental protections. The country is surrounded by both the Atlantic and the Pacific, and its extensive coastlines are home to seven of the world’s eight sea turtle species.
Read More: Fishing Companies Are Trying to Hide How Penguins Are Showing Up Dead in Their Nets
Overdevelopment, pollution, overfishing, and climate change have converged in recent years to make conditions inhospitable for turtles, according to the Conversation.
But Mexico has taken steps to improve this situation. Independent conservation teams are tasked with protecting each of the seven turtle species and marine sanctuaries have been established in recent years.
Still, two separate incidents of hundreds of endangered turtles dying show that more must be done.