UNC-TV Science: February 19, 2014
UNC Pembroke Research Helps Protect Leatherback Sea Turtles
The leatherback sea turtle has been endangered since 1970, before Congress even passed the Endangered Species Act. The leatherback naturally falls victim to hunting and the rough seas that it lives in, but more recently its scourge has been fishing trawls that accidentally scoop up turtles in their huge nets, in a process called bycatch.
But new research from institutions around the world may help to limit the number of encounters that these commercial fishing boats have with leatherback turtles.
The team of scientists, led by UNC Pembroke biologist John Roe, tracked 135 adult leatherback turtles in the Pacific Ocean from 1992 until 2008 using satellite transmitters. They compared that data to data they gathered from the Secretariat of the Pacific Community and the United Nations on the positions, catches and gear of commercial fishing boats in the Pacific.
Then, the team constructed a model using both data sets to find “hotspots” where leatherback bycatch would most likely happen. Click here to see the finished map of bycatch hotspots.
The leatherback turtle is the largest turtle on the planet. They can grow up to seven feet long and weigh more than a ton, which is large enough to break commercial fishing equipment. The leatherbacks suffered a severe drop in population between 1980 and 1995, plummeting from 115,000 nesting females to 34,500 during that time. Since 1995, the leatherbacks have recovered, as studies estimate that 34,000 to 94,000 adult leatherbacks now live in the North Atlantic alone.
Roe’s study, which also included biologist Scott Eckert, formerly of Duke University’s Marine Lab, aims to inform commercial fishers so that leatherback turtles can continue to rebound.
The results showed vast differences between the “location, size and timing” of the bycatch spots in the East and West Pacific, and the authors stress that ideally, any restrictions put on commercial fishers would treat these two geographic areas separately.
But “hotspots” aren’t the only concerns in protecting the turtles. The researchers found that the channel between the Galapagos Islands and Costa Rica, which was not predicted to be a particularly bad “hotspot,” is a migratory path for nesting adults. Therefore, even though this area is not a “hotspot” the authors point out that this area should be protected because the leatherbacks are at a very important stage of their life cycle as they swim through this area, and capturing turtles here would not only harm the turtles that get caught but also the nests they were on their way to creating.
The authors acknowledge that this study is a starting point, but hope that it can lead to more studies in particular regions and inform general thinking about how to prevent commercial fishers from trapping the endangered turtles.
The study appeared in the journal Proceedings of the Royal Society B and Roe said in press release that another study on leatherbacks in the Atlantic will be published in the next few months.
- Daniel Lane
Daniel Lane covers science, medicine and the environment as a reporter/writer. He is currently pursuing a master's degree in medical and science journalism at UNC - Chapel Hill.