Marine Turtle Biotelemetry

The Marine Turtle Ecology & Assessment Program researchers utilize biotelemetry techniques to study the movements and habitat use of marine turtles in the Pacific. The telemetry tools that we use include Argos-linked GPS transmitters, Argos-only transmitters, acoustic transmitters with active and passive tracking systems, time-depth recorders, and turtle-borne video systems.  In addition to the application of transmitters to study sea turtle biology, we have also conducted research to study hydrodynamic drag of telemetry packages, which has resulted in a series of recommendations about what the best transmitters and tagging locations are for telemetry research in sea turtles. You can find more information on species-specific biotelemetry below.

Leatherback Turtle

Western Pacific leatherback turtles (Dermochelys coriacea)migrate over 10,000 kilometers to forage in Eastern Pacific waters off the west coast of the United States. These long ranging animals originate from nesting grounds in the West Pacific. Researchers use satellite tags to understand movements and habitat use of these endangered animals as they migrate to and from their nesting grounds. Our team has largely applied satellite tags to leatherback turtles at foraging areas along the central coast of California, although in earlier years we also tagged nesting females in Indonesia, Solomon Islands, and Papua New Guinea. These tracks revealed trans-Pacific movements as well as foraging areas in the eastern Australia current, Tasman Sea, South China Sea, and North Pacific Transition Zone.

Leatherback turtle with suction cup-mounted video camera system photographed offshore of central California. Photo: NOAA Fisheries/Scott Benson.

Hawksbill Turtle

Until very recently, hawksbill turtles (Eretmochelys imbricata) in the Eastern Tropical Pacific Ocean were widely considered to be beyond the point of recovery. However, nesting beach monitoring efforts in the last decade have established that nearly 500 nests are laid each year in the region, with the most important nesting beaches in El Salvador and Nicaragua. With a renewed sense of urgency, this project launched in July 2008, aims to pinpoint the migratory corridors and foraging area hotspots of Critically Endangered hawksbill turtles in the region. So far we have applied both Argos satellite tags and Argos-linked GPS tags to hawksbills in Mexico, El Salvador, Nicaragua, Panama, and Ecuador. For the latest tracking data, please visit the sea turtle online tracking website on the SEATURTLE.ORG page.

Hawksbill turtle with satellite tag in El Salvador. Credit: Bryan P. Wallace.

Loggerhead Turtle

Loggerheads (Caretta caretta) in the Eastern Pacific occur largely off the west coast of the Baja California Peninsula, Mexico. In warm water periods they can also be found in waters off southern California, is our primary area of research. So far, satellite telemetry data has provided information on daily movements of juvenile loggerheads in relation to oceanographic features such as sea surface temperature and surface currents. We’ve conducted satellite telemetry of loggerhead turtles in Mexico, Peru, and most recently in southern California. For the latest tracking data for loggerheads in southern California, please visit the sea turtle online tracking website.

Loggerhead turtle with small satellite tag ready for release from Sportfishing Vessel Outer Limits. Credit: Ralph Pace.

Green Turtle

East Pacific green turtles (Chelonia mydas) occupy coastal foraging grounds in Southern California, including NOAA Fisheries study sites in San Diego Bay, San Gabriel River, and Seal Beach National Wildlife Refuge. Our biotelemetric research in these areas centers on understanding local movements and habitat use, and in the process we have also been able to document the foraging area-to-nesting beach migrations of at least four turtles. The telemetry tools that we use include Argos-linked GPS transmitters, Argos-only transmitters, acoustic transmitters with active and passive tracking systems, time-depth recorders, and turtle-borne video systems.

Green turtle with satellite tag in San Diego Bay. Photo: NOAA Fisheries/Jeffrey Seminoff.

Satellite Telemetry Resources

• Wildlife Computers
• Sonotronics 
• Telonics
• Sirtrack
• SMRU
• CLS (Argos)

Select Publications

Benson, S. R., T. Eguchi, D. G. Foley, K. A. Forney, H. Bailey, C. Hitipeuw, B. P. Samber, R. F. Tapilatu, V. Rei, P. Ramohia, J. Pita, and P. H. Dutton. 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, S. R., K. A. Forney, J. T. Harvey, J. V. Carretta, and P. H. Dutton. 2007b. Abundance, distribution, and habitat of leatherback turtles (Dermochelys coriacea) off California, 1990 –2003. Fishery Bulletin 105:337–347.

Crear, D. P., Lawson, D. D., Seminoff, J. A., Eguchi, T., Le Roux, R. A., & Lowe, C. G. (2016). Seasonal shifts in the movement and distribution of green sea turtles Chelonia mydas in response to anthropogenically altered water temperatures. Marine Ecology Progress Series, 548, 219–232. 

Crear, D. P., Lawson, D. D., Seminoff, J. A., Eguchi, T., LeRoux, R. A., & Lowe, C. G. (2017). Habitat use and behavior of the east Pacific green turtle, Chelonia mydas in an urbanized system. Bulletin of the Southern California Academy of Sciences, 116(1), 17–32.

Eguchi, T., J.A. Seminoff, S.A. Garner, J. Alexander-Garner, P.H. Dutton. 2006. Flipper tagging with archival data recorders for short term assessment of diving in nesting female turtles. Endangered Species Research 2:1-7

Gaos, A.R., R.R. Lewison, I.L. Yañez, W.J. Nichols, A. Baquero, M. Liles, M. Vasquez, J. Urteaga, B.P. Wallace, and J.A. Seminoff. 2011. Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles. Biology Letters. doi:10.1098/rsbl.2011.0603

Gaos, A.G., R.R. Lewison, I.L. Yañez, B.P. Wallace, M.J. Liles, W.J. Nichols, A. Baquero, C.R. Hasbún, M. Vasquez, J. Urteaga, and J.A. Seminoff. 2012. Spatial ecology of critically endangered hawksbill turtles (Eretmochelys imbricata (Linnaeus)) in the eastern Pacific Ocean. Marine Ecology Progress Series. 450:181-194.

Gaos, A., Lewison, R., Wallace, B.P., Yanez, I., Liles, M., Baquero, A., Seminoff, J.A. 2012. Dive behaviour of adult hawksbills (Eretmochelys imbricata, Linnaeus 1766) in the eastern Pacific Ocean highlights shallow depth use by the species. Journal of Experimental Marine Biology and Ecology 432:171-178

Jones, T.T., B. Bostrom, M. Carey, B. Imlach, J. Mickelson, S. Eckert, P. Opay, Y. Swimmer, J.A. Seminoff, and D.R. Jones. 2011. Determining transmitter drag and best-practice attachment procedures for sea turtle biotelemetry studies. NOAA Technical Memorandum. NOAA-NMFS-SWFSC-480

Jones, T.T., B.L. Bostrom, K.S. Van Houtan, P. Ostafichuk, J. Mikkelsen, E. Tezcan, M. Carey, B. Imlach, J.A. Seminoff. 2013. Ecological implications of biotelemetry drag in marine macro-vertebrates. Methods in Ecology and Evolution doi: 10.1111/2041-210X.12109.

MacDonald, B. D., Madrak, S. V., Lewison, R. L., Seminoff, J. a., & Eguchi, T. (2013). Fine scale diel movement of the east Pacific green turtle, Chelonia mydas, in a highly urbanized foraging environment. Journal of Experimental Marine Biology and Ecology, 443, 56–64.

MacDonald, B., Lewison, R., Madrak, S., Seminoff, J., & Eguchi, T. (2012). Home ranges of East Pacific green turtles Chelonia mydas in a highly urbanized temperate foraging ground. Marine Ecology Progress Series, 461, 211–221.

Madrak, S. V., Lewison, R. L., Seminoff, J. A., & Eguchi, T. (2016). Characterizing response of East Pacific green turtles to changing temperatures: using acoustic telemetry in a highly urbanized environment. Animal Biotelemetry, 4(1), 22.

Mangel, J.C., J. Alfaro-Shigueto, M.J. Witt, P.H. Dutton, J.A. Seminoff, and B.J. Godley. 2011. Post-capture movements of loggerhead turtles in the southeastern Pacific Ocean assessed by satellite tracking. Marine Ecology Progress Series 433:261-272

Nichols, W.J., A. Resendiz, J.A. Seminoff, and B. Resendiz. 2000. Transpacific loggerhead turtle migration monitored with satellite telemetry. Bulletin of Marine Science 67:937-947

Seminoff JA, Resendiz A, Nichols WJ (2002) Home range of the green turtle (Chelonia mydas) at a coastal foraging ground in the Gulf of California, México. Marine Ecology Progress Series 242:253–265

Seminoff JA, Jones TT (2006) Daily movements and activity ranges of green turtles (Chelonia mydas) at a coastal foraging area in the Gulf of California, Mexico. Herpetological Conservation and Biology 1:81–86

Seminoff, J.A. and P. Zárate. 2008. Satellite-tracked migrations by Galápagos green turtles and the need for multinational conservation efforts. Current Conservation. 2:11-12

Seminoff, J.A., P. Zárate, M. Coyne, D. Foley, D. Parker, B.N. Lyon, and P.H. Dutton. 2008. Post-nesting migrations of Galapagos green turtles, Chelonia mydas, in relation to oceanographic conditions: integrating satellite telemetry with remotely-sensed ocean data. Endangered Species Research 4:57-72

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