Stable isotope analyses of cold-stunned Kemp’s ridley (Lepidochelys kempii) sea turtles at the northern extent of their coastal range
Kemp’s ridley (Lepidochelys kempii) sea turtles strand on Cape Cod, USA (41.894757°N, − 70.289372°W) as water temperatures drop in November, but little is known about their pre-stranding ecology. Carbon and nitrogen stable isotope values of soft tissues (liver and muscle) and scutes (anterior edge and interior) from cold-stunned individuals (n = 26) sampled from 2006 to 2008 were used to assess general patterns of local and early life-history habitat use. After adjusting for trophic discrimination, anterior scute carbon and nitrogen isotope values (n = 11) representative of recent feeding were lower and higher, respectively, than potential offshore prey but similar to many local neritic prey and sea turtle-derived isoscapes for New England waters. These results combined with a significant increase in δ15N values for scute edge relative to scute interior samples representative of early life history suggest local foraging prior to stranding. Interior scute δ13C and δ15N values mirrored Gulf of Mexico isoscapes, consistent with early life-history foraging near nesting habitat. Liver (rapid) and muscle (slow turnover) isotope offsets differed among individuals (n = 15), suggesting that the cold-stunned population does not have a homogenous migratory and/or trophic history. Liver tissue showed evidence of starvation-induced δ15N alteration, which could bias interpretation of isotope data from rapid turnover tissues. Further stable isotope analyses including complementary tracers and techniques will improve our knowledge of this poorly understood assemblage at the northern extent of the species’ coastal range. Such data will aid managers in preserving foraging habitat and prey resources in New England waters that may become increasingly important if Kemp’s ridley distribution shifts polewards with climate change.
We thank Andrew Ouimette and the staff of the University of New Hampshire Stable Isotope Laboratory for performing elemental composition and stable isotope analyses. Keith Matassa provided assets, both financial and material, for the completion of this project. Heather Haas, Samir Patel, Lindsey Peavey Reeves, and one anonymous reviewer provided insightful edits to previous versions of this manuscript. David Taylor, Maureen Conte, Emily DeFelippis, Ruth Carmichael, Eric Morgan, and Rainer Lohmann generously provided raw stable isotope and elemental composition data to allow for comparison with our dataset. We thank Robert Prescott and all of the staff and volunteers of Mass Audubon’s Wellfleet Bay Wildlife Sanctuary who tirelessly walk the cold beaches of Cape Cod searching for live and dead cold-stunned sea turtles. Finally, we want to recognize the numerous staff and volunteers of the New England Aquarium who care for the stranded turtles, as well as those of the secondary care facilities who continue the rehabilitation prior to release.
Compliance with ethical standards
Conflict of interest
The authors declare they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.
- Bleakney JS (1965) Reports of marine turtles from New England and eastern Canada. Can Field Nat 79:120–128Google Scholar
- Bolten AB (2003) Variation in sea turtle life history patterns: neritic vs. oceanic developmental stages. In: Lutz PL, Musick JA, Wyneken J (eds) The biology of sea turtles, vol II. CRC Press, Boca Raton, pp 243–257Google Scholar
- Burke VJ, Morreale SJ, Standora EA (1994) Diet of the Kemp’s ridley sea-turtle, Lepidochelys kempi, in New York waters. Fish Bull 92:26–32Google Scholar
- Carr A (1967) So excellent a fishe: a natural history of sea turtles. Scribner, New YorkGoogle Scholar
- DeFelippis E, Conte M, Weber JC (2017) Lipids and stable isotope profiles in cold stunned juvenile sea turtles of Cape Cod. Unpublished Report. Semester in Environmental Science. Ecosytem Center of the Marine Biological Laboratory. http://www.mbl.edu/ses/files/2018/02/DeFelippis_Final-Paper.pdf. Accessed 7 Dec 2018
- Epperly SP, Heppell SS, Richards RM, Castro Martínez MA, Zapata Najera BM, Sarti Martínez AL, Peña LJ, Shaver DJ (2013) Mortality rates of Kemp’s ridley sea turtles in the neritic waters of the United States. In: Tucker T, Belskis L, Panagopoulou A, Rees A, Frick M, Williams K, LeRoux R, Stewart K (eds) Proceedings of the thirty-third annual symposium of sea turtle biology and conservation. NOAA Technical Memorandum NMFS-SEFSC 645, p 219Google Scholar
- Graham BS, Koch P, Newsome S, McMahon KW, Aurioles D (2010) Using isoscapes to trace the movements and foraging behavior of top predators in oceanic ecosystems. In: West JB, Bowen GJ, Dawson TE, Tu KP (eds) Isoscapes: understanding movement, pattern and processes on Earth through isotope mapping. Springer, New YorkGoogle Scholar
- Kenney RD, Vigness-Raposa KJ (2010) Chapter 10. Marine mammals and sea turtles of Narragansett Bay, Block Island Sound, Rhode Island Sound, and nearby waters: an analysis of existing data for the Rhode Island Ocean Special Area Management Plan. In: RICRMC (Rhode Island Coastal Resources Management Council) Ocean Special Area Management Plan (SAMP), vol 2Google Scholar
- Kraus SD, Leiter S, Stone K, Wikgren B, Mayo C, Hughes P, Kenney RD, Clark CW, Rice AN, Estabrook B, Tielens J (2016) Northeast large pelagic survey collaborative aerial and acoustic surveys for large whales and sea turtles. U.S. Department of the Interior, Bureau of Ocean Energy Management, Sterling, Virginia. OCS Study BOEM 2016-054Google Scholar
- Liu X, Manning J, Prescott R, Zou H, Faherty M (2018) On simulating cold stunned turtle strandings on Cape Cod. bioRxiv. https://doi.org/10.1101/418335
- Morreale SJ, Standora EA (2005) Western North Atlantic waters: crucial developmental habitat for Kemp’s ridley and loggerhead sea turtles. Chelonian Conserv Biol 4:872–882Google Scholar
- Newell RIE (1989) Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (North and Mid-Atlantic)–blue mussel. United States Fish and Wildlife Service, Biological Report 82(11.102). U.S. Army Corps of Engineers, TR E1-82-4, pp 25Google Scholar
- Ogren LH (1989) Distribution of juvenile and subadult Kemp’s ridley sea turtles: preliminary results from 1984-1987 surveys. In: Caillouet Jr CW, Landry Jr AM (eds) Proceedings of the first international symposium on Kemp’s ridley sea turtle biology, conservation, and management, pp 116–123Google Scholar
- Plotkin P (2003) Adult migrations and habitat use. In: Lutz PL, Musick JA, Wyneken J (eds) The biology of sea turtles, vol II. CRC Press, Boca Raton, pp 225–241Google Scholar
- Poloczanska ES, Limpus CJ, Hays GC (2009) Vulnerability of marine turtles to climate change. In: Sims DW (ed) Advances in marine biology, vol 56. Academic Press, Burlington, pp 151–211Google Scholar
- Seminoff JA, Benson SR, Arthur KE, Eguchi T, Dutton PH, Tapilatu RF, 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. https://doi.org/10.1371/journal.pone.0037403 CrossRefPubMedPubMedCentralGoogle Scholar
- R Core Team (2016) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. http://www.R-project.org/
- Vander Zanden HB, Tucker AD, Hart KM, Lamont MM, Fujisaki I, Addison DS, Mansfield KL, Phillips KF, Wunder MB, Bowen GJ, Pajuelo M, Bolten AB, Bjorndal KA (2015a) Determining origin in a migratory marine vertebrate: a novel method to integrate stable isotopes and satellite tracking. Ecol Appl 25:320–335CrossRefGoogle Scholar