SOUTH PADRE ISLAND, Texas (Border Report) — Dozens of sea turtles have been killed recently off South Texas waters due to gill-netting — a fishing practice that is illegal in U.S. waters of the Gulf of Mexico, but one that happens when Mexican fishing vessels slip north, which is happening with more frequency, officials said.

In December, 49 dead sea turtles were found off the South Texas beaches of South Padre Island and Boca Chica Beach, Wendy Knight, executive director of the nonprofit organization Sea Turtle Inc., told NewsNation affilate Border Report.

Necropsy reports done on the juvenile green turtles found that they died due “to forced submersion, which is drowning,” Knight said.

The Padre Island National Seashore Division of Sea Turtle Science & Recovery has posted on its Facebook page gruesome photos of the turtles with the green plastic gill-netting choking the amphibians around the neck and fins.

“Biologists hypothesize that some or all were captured due to illegal gill netting in nearshore Gulf of Mexico waters off the South Texas coast. The U.S. Coast Guard and Texas Parks and Wildlife Department capture several vessels illegally entering U.S. waters from Mexico for fishing each year, and those numbers have increased in recent years,” according to the Dec. 30 post.

Sea turtles, all of which are listed as threatened or endangered species, are protected by federal laws and the U.S. Coast Guard is increasing monitoring “hotspot stranding areas and recovery of this deadly fishing gear and any entangled sea turtles,” the federal organization wrote.

Knight said a few necropsy reports are still outstanding “but they all appear to be relative to the same issue.”

This comes a year after over 100 sea turtles were found dead in November and December 2019, all attributed to illegal gill-net fishing tied back to Mexican nationals using illegal netting in U.S. waters, Knight said.

“We did have this same issue happen last year (2019) almost about the same time,” Knight said. “And the Coast Guard actually caught and arrested illegal gill-fishers out in the ocean, thanks to increased patrols.”

Foggy winter weather helps to provide cover that allows fishermen to slip north and deploy illegal fishing devices.

“It’s about this time of year, I think the fog contributes to it. It gives them kind of a place to hide,” Knight said. “In the issue last year (2019) it was Mexican nationals coming across international waters.”

Knight said that the recent turtle drownings have not yet been identified with any group of fishermen. “They did also find gill-nets in the water and were able to collect those and get those out of the way. But we have not identified who or where the fishers came from. But this looks exactly like you think it does,” she said.

Knight said turtles are not the only sea creatures that get trapped in the netting; dolphins and other large marine life that require breath also die in the nets “and are stuck in the nets until they drown.”

Earlier this month, two fishermen were injured off Mexico’s Baja California coast when they rammed their small boat into a larger vessel in the waters to protect the endangered vaquita porpoise, which was being threatened by banned gill nets in the Gulf of California. Only as few as a dozen vaquitas are believed to remain, making them the world’s most endangered marine mammal. Gill-net fishing has been banned in the Gulf of California waters since 2017.

A report by the Brookings Institute in September criticized the Mexican government for being unable to regulate gill-net fishing off Baja California. “Mexico’s very long coastline and a fishing fleet involving over 100,000 small vessels, known as pangas, makes enforcement on the seas and on land that serves as launching places of fishermen challenging. Illegal fishing is estimated to account for between 45% and — a staggering — 90% of official fish production in Mexico,” according to the report.

Sea Turtle Inc., along with Texas Parks and Wildlife Department, volunteers, residents and local businesses work to help locate any sea turtles affected by illegal fishing nets. A 24-hour hotline for sightings in South Texas can be reached at 956-243-4361.