Trapped turtles: Quick action by New England fishermen can help save tangled leatherbacks

Leatherback sea turtles have a low chance of surviving if they're only partially disentangled from rope

BOSTON - According to a new study, leatherback turtles that become entangled in fishing gear have a higher chance of surviving if the incident is reported quickly.

Dr. Kara Dodge of the New England Aquarium, and her team of researchers, analyzed 15 years of data collected by disentanglement responders to better understand sea turtle bycatch and mortality.

The National Oceanic and Atmospheric Administration defines bycatch as the process in which fishermen catch and discard animals they don't want, can't sell or are not allowed to keep. Bycatch can be fish but includes other animals such as dolphins, whales, sea turtles and seabirds that get hooked or tangled in fishing gear.

The findings showed that of the 280 confirmed sea turtle entanglements in Massachusetts waters between 2005-2019, 272 involved leatherback turtles, with most wrapped in rope around their necks and front flippers.


And according to the study in Endangered Species Research, 88% of disentangled turtles were predicted to have a low or intermediate risk of death. 

The study also found that among the turtles that were tagged to track their movements, many were alive weeks to years after being disentangled.

"This dataset gave us a unique opportunity to really dig into and understand leatherback turtle entanglement in buoy lines, which is critical to determining how entanglement happens and identifying workable solutions to solve this problem," Dodge said.

Leatherback turtles are among the most endangered sea turtle species, and they can reach 6 feet in length and can weigh over 1,000 lbs.

"Our findings for leatherbacks mirrors what we have seen in whales. They are very likely to become entangled in whatever rope is most available to them. Reducing rope, which is not meant to mean reducing fishing, will be the best strategy for reducing entanglements," said study co-author Scott Landry of the Center for Coastal Studies, which leads entanglement response efforts in the region and collected the bulk of the data for the study.


Researchers stressed the importance of sea turtles being completely disentangled, as they will have a low chance of survival if they're only partially disentangled.

The disentanglement network works with fishermen and relies on them to immediately report an entanglement and wait for a team to arrive to help.

"We really want boaters to inform us as soon as possible when they encounter an entangled turtle so that we can assess the turtle's condition and provide medical treatment if needed," said Dr. Charles Innis, director of animal health at the New England Aquarium and a co-author of the study.

Innis said boaters mean well when they try and help the turtles, but that can lead to a lower chance of survival and prevent teams from learning more about the effects of entanglements on the turtles.

The study showed that most of the turtles that were caught were tangled in commercial fishing gear and not other debris. And some potential solutions to reduce the risk of leatherback sea turtles getting tangled would be replacing single fixed-gear fishing traps with trawls to reduce the number of vertical lines. 

The researchers also encourage the development of emerging technologies, particularly "ropeless" fishing.

And while the study focused on entanglements in the waters off the coast of Massachusetts, researchers said challenges facing sea turtles are not only limited to that area. Other studies showed entanglements are also a problem for leatherback sea turtles in Canadian waters.

Anyone who sees a sea turtle tangled in rope off southern New England should immediately report it to local responders, including the Center for Coastal Studies at 1-800-900-3622.