Leatherback Turtle Research

Adult leatherback turtle aboard the R/V Sheila B., a research vessel from Moss Landing Marine Laboratories. Photo: NOAA Fisheries/Scott Benson

Everything about the leatherback sea turtle (Dermochelys coriacea) is large. It can weigh over 450 kg (1,000 lbs) and grow to more than 2 m (6 ft) in length. It undertakes the longest migration of any air-breathing marine vertebrate, with leatherbacks nesting in Papua, Indonesia in the western Pacific migrating to the west coast of the United States, a journey of more than 10,000 km. It is this long migration that makes Pacific leatherbacks so vulnerable to anthropogenic impacts. Unfortunately, the Pacific leatherback is critically endangered, with an estimated decline of nearly 80% in the last few decades. NMFS has taken major steps to promote the recovery of this species. In 2001, the Pacific Leatherback Conservation Area (PLCA) was established, which prohibits drift-gillnet fishing for swordfish in leatherback foraging grounds off California, Oregon, and Washington from August 15 to November 15 each year. Critical habitat for leatherback turtles was designated off the US West Coast in 2012. Leatherbacks arrive along the U.S. west coast in spring and summer to forage on abundant sea jellies (especially the brown sea nettle, Chrysaora fuscescens) that bloom due to seasonal upwelling along the coast. The PLCA has significantly reduced by-catch while still allowing fishing in times when leatherbacks are not present.

Since the establishment of the PLCA, scientists from the Marine Turtle Ecology & Assessment Program (MTEAP) at SWFSC have conducted annual assessments and research on leatherbacks foraging off the U.S. West Coast to learn more about diving behavior, migration routes, as well as gathering important data on foraging ecology, health, and population structure. The team uses a variety of research methods and technologies for their research, including aerial surveys, in-water capture, turtle-borne video, satellite telemetry, stable isotope analysis, and health assessment.   

If you see a leatherback, please report your sighting to swfsc.turtle-sightings@noaa.gov, including location (latitude and longitude would be best but any major landmarks are also good), species (if possible), date and time, behavior, and photos (if possible). 

Leatherback turtle nesting in Jamursba-Medi, Papua, Indonesia. Photo: NOAA Fisheries/Manjula Tiwari

Select Publications from our Team 

Benson SR, Tapilatu RF, Pilcher N, Santidrián Tomillo P, Sarti Martinez L (2015) Leatherback turtle populations in the Pacific. In: Spotila, J. (Ed.), The Leatherback Turtle: Biology and Conservation. The Johns Hopkins University Press.

Benson SR, Eguchi T, Foley DG, Forney KA, Bailey H, Hitipeuw C, Samber BP, Tapilatu RF, Rei V, Ramohia P, Pita J, Dutton PH (2011) Large-scale movements and high-use areas of western Pacific leatherback turtles, Dermochelys coriacea. Ecosphere 2(7):art84. doi:10.1890/ES11-00053.1

Benson SR, Dutton PH, Hitipeuw C, Samber B, Bakarbessy J, Parker D (2007a). Post-nesting migrations of leatherback turtles (Dermochelys coriacea) from Jamursba-Medi, Birds Head Peninsula, Indonesia. Chelonian Conservation and Biology 6:150–154. 

Benson SR, Forney KA, Harvey JT, Carretta JV, Dutton PH (2007b) Abundance, distribution, and habitat of leatherback turtles (Dermochelys coriacea) off California, 1990 –2003. Fishery Bulletin 105:337–347.

Benson SR, Kisokau KM, Ambio L, Rei V, Dutton PH, Parker D (2007c) Beach use, internesting movement, and migration of leatherback turtles, Dermochelys coriacea, nesting on the north coast of Papua New Guinea. Chelonian Conservation and Biology 6:7–14.

Curtis, K.A., Moore, J.E., Benson, S.R. 2015. Estimating Limit Reference Points for Western Pacific Leatherback Turtles (Dermochelys coriacea) in the U.S. West Coast EEZ. PLoS ONE 10(9): e0136452. doi:10.1371/journal.pone.0136452

Dutton PH, Bowen BW, Owens DW, Barragan A, Davis S (1999) Global phylogeography of the leatherback turtle (Dermochelys coriacea). Journal of Zoology 248:397–409. 

Dutton PH, Frey A, LeRoux R, Balazs G (2000) Molecular ecology of leatherback turtles in the Pacific. Pages 248–253 in N. Pilcher and G. Ismail, editors. Sea turtles of the Indo-Pacific: Research, management and conservation. ASEAN Academic Press, London.

Dutton PH, Hitipeuw C, Zein M, Benson SR, Petro G, Pita J, Rei V, Ambio L, Bakarbessy J (2007) Status and genetic structure of nesting populations of leatherback turtles. 

Eguchi T, Benson SR, Foley DG,  Forney KA (2017) Predicting overlap between drift gillnet fishing and leatherback turtle habitat in the California current ecosystem. Fisheries Oceanography 26:17-33

Howell EA, Hoover A, Benson SR, Polovina JJ, Bailey H, Seminoff JA, Dutton PH (2015) TurtleWatch 2.0: Adapting the NOAA TurtleWatch product to aid in the bycatch reduction of leatherback turtles (Dermochelys coriacea) in the Hawaii-based pelagic longline fishery. In NOAA Review for Fisheries Oceanography. doi:10.1111/fog.12092

Okuyama J, Seminoff JA, Dutton PH, Benson SR (2016) Fine-scale monitoring of routine deep dives by gravid leatherback turtles during the interesting interval indicate a capital breeding strategy. Frontiers in Marine Science. doi: 10.3389/fmars.2016.00166 

Roe JH, Morreale SJ, Paladino FV, Shillinger GL, Benson SR, Eckert SA, Bailey H, Santidrián-Tomillo P, Bograd SJ, Eguchi T, Dutton PH, Seminoff JA, Block BA, Spotila JR. (2014) Predicting hotspots of interaction between critically endangered leatherbacks and longline fisheries in the Pacific Ocean. Proceedings of the Royal Society B. 281:20132559.

Seminoff JA, Dutton PH (2007) Leatherback sea turtles (Dermochelys coriacea) in the Gulf of California: distribution, demography, and human interactions. Chelonian Conservation and Biology 6:137-141

Seminoff JA, Benson SR, Arthur KE, Eguchi T, Dutton PH, Tapilatu R, Popp BN (2012) Stable isotope tracking of endangered sea turtles: validation with satellite telemetry and δ¹⁵N analysis of amino acids. PLoS ONE. 7(5): e37403. doi:10.1371/journal.pone.0037403

Meet our Team

Dr. Jeffrey Seminoff is the lead for this project,