Dermochelys coriacea (Southeast Atlantic Ocean subpopulation)
|Scientific Name:||Dermochelys coriacea (Southeast Atlantic Ocean subpopulation)|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Tiwari, M., Wallace, B.P. & Girondot, M.|
|Reviewer(s):||Chaloupka, M.Y., Bolten, A.B., Dobbs, K., Limpus, C., Nel, R., Eckert, K.L., Mortimer, J.A., Pritchard, P.C.H., Dutton, P.H., van Dijk, P.P., Casale, P. & Miller, J.|
|Contributor(s):||Honarvar, S., Formia, A., Girard, A. & Beheret, N.|
The nesting epicenter for the Southeast Atlantic Leatherback subpopulation lies in Bioko Island, Equatorial Guinea, Gabon, and the Republic of Congo, with additional nesting in much smaller numbers extending north to Senegal and south to Angola (Turtle Expert Working Group 2007, Fretey et al. 2007a, Witt et al. 2009). Dutton et al. (2013) found that the West African rookeries sampled (Gabon and Ghana) were genetically different (mitochondrial DNA and microsatellites) from the other Atlantic rookeries and the South African rookery sampled, and that even Gabon and Ghana were fairly well differentiated based on mitochondrial DNA, but more weakly differentiated based on microsatellite data. The marine habitat for this subpopulation is thought to extend from the Atlantic coast of Africa south to the equator and southwest to Brazil, Uruguay, and Argentina and southeast to South African waters (Figure 1 in Supplementary Material), but the northern geographic boundaries lack resolution. Continuous long-term data sets, complete data on genetic stocks, and reliable estimates of the number of mature individuals are unavailable for this subpopulation. Furthermore, the majority of abundance in this subpopulation occurs in Gabon (TEWG 2007, Witt et al. 2009), for which long-term data are unavailable. Therefore this subpopulation is classified as Data Deficient for all applicable criteria (A, B, C, and D).
Criterion A could not be evaluated for this subpopulation because the majority of nesting in this subpopulation occurs in Gabon, for which trend data are unavailable. Although data were available from the other two major nesting sites (Table 1 in Supplementary Material), the cumulative abundance of these two sites is <10% the abundance in Gabon. Therefore, it was inappropriate to assign the trends observed in Congo and Equatorial Guinea to the entire subpopulation.
We assessed the status of the Southeast Atlantic Leatherback subpopulation by Criteria A-D; as no population viability analysis has been performed, Criterion E could not be applied.
Leatherbacks are distributed circumglobally, with nesting sites on tropical sandy beaches and migratory and foraging ranges that extend into temperate and sub-polar latitudes. The nesting epicentre for the Southeast Atlantic Leatherback subpopulation lies in Bioko Island, Equatorial Guinea, Gabon, and the Republic of Congo with nesting extending in smaller numbers north to Senegal and south to Angola (Turtle Expert Working Group 2007, Fretey et al. 2007a, Witt et al. 2009). See Eckert et al. (2012) for review of Leatherback geographic range, and Fretey et al. (2007a) for a regional review.
Native:Angola; Argentina; Benin; Brazil; Cameroon; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Equatorial Guinea (Bioko); Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Liberia; Namibia; Nigeria; Saint Helena, Ascension and Tristan da Cunha; Sao Tomé and Principe; Senegal; Sierra Leone; South Africa; Togo; Uruguay
|FAO Marine Fishing Areas:|
Atlantic – western central; Atlantic – southwest; Atlantic – southeast; Atlantic – northwest; Atlantic – northeast; Atlantic – eastern central
|Range Map:||Click here to open the map viewer and explore range.|
Leatherbacks are a single species globally comprised of biologically described regional management units (RMUs; Wallace et al. 2010), which describe biologically and geographically explicit population segments by integrating information from nesting sites, mitochondrial and nuclear DNA studies, movements and habitat use by all life stages. RMUs are functionally equivalent to IUCN subpopulations, thus providing the appropriate demographic unit for Red List assessments. There are seven Leatherback subpopulations, including the Southeast Atlantic Ocean, Southwest Atlantic Ocean, Northwest Atlantic Ocean, Northeast Indian Ocean, Southwest Indian Ocean, East Pacific Ocean, and West Pacific Ocean. Multiple genetic stocks have been defined according to geographically disparate nesting areas around the world (Dutton et al. 1999) and in the Atlantic Ocean, in particular (Dutton et al. 2013), and are included within RMU delineations (Wallace et al. 2010; shapefiles can be viewed and downloaded at: http://seamap.env.duke.edu/swot).
|Current Population Trend:||Unknown|
|Habitat and Ecology:|
See the species account for a summary of the details. For a thorough review of Leatherback biology, please see Eckert et al. (2012).
|Generation Length (years):||30|
|Use and Trade:||Eggs and female turtles are harvested for human consumption as well as for use in traditional medicine and voodoo practices|
Threats to Leatherbacks (and other marine turtle species), vary in time and space, and in relative impact to populations. Threat categories were defined by Wallace et al. (2011) as the following:
1) Fisheries bycatch: incidental capture of marine turtles in fishing gear targeting other species;
2) Take: direct utilization of turtles or eggs for human use (i.e. consumption, commercial products);
3) Coastal Development: human-induced alteration of coastal environments due to construction, dredging, beach modification, etc.;
4) Pollution and Pathogens: marine pollution and debris that affect marine turtles (i.e. through ingestion or entanglement, disorientation caused by artificial lights), as well as impacts of pervasive pathogens (e.g. fibropapilloma virus) on turtle health;
5) Climate change: current and future impacts from climate change on marine turtles and their habitats (e.g. increasing sand temperatures on nesting beaches affecting hatchling sex ratios, sea level rise, storm frequency and intensity affecting nesting habitats, etc.).
The relative impacts of individual threats to all Leatherback subpopulations were assessed by Wallace et al. (2011). At a global scale, fisheries bycatch was classified as the highest threat to Leatherbacks globally, followed by human consumption of Leatherback eggs, meat, or other products and coastal development. Due to lack of information, pollution and pathogens was only scored in three subpopulations and climate change was only scored in two subpopulations. Enhanced efforts to assess the impacts of these threats on Leatherbacks—and other marine turtle species—should be a high priority for future research monitoring efforts.
For this Southeast Atlantic subpopulation, accidental capture in fisheries is one of the biggest threats (e.g., Carranza et al. 2006, Witt et al. 2011, Wallace et al. 2013, Riskas and Tiwari 2013), along with harvest of eggs and females for consumption as well as for use in traditional medicine and voodoo practices, oil exploitation activities, chemical and industrial pollution as well as sand mining (Fretey et al. 2007a,b; Wallace et al. 2011). The impact of these and other threats such as predation and erosion have not been sufficiently quantified.
Leatherbacks are protected under various national and international laws, treaties, agreements, and memoranda of understanding. A partial list of international conservation instruments that provide legislative protection for Leatherbacks are: Annex II of the SPAW Protocol to the Cartagena Convention (a protocol concerning specially protected areas and wildlife); Appendix I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora); and Appendices I and II of the Convention on Migratory Species (CMS); the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC), the Memorandum of Understanding on the Conservation and Management of Marine Turtles and their Habitats of the Indian Ocean and South-East Asia (IOSEA), the Memorandum of Understanding on ASEAN Sea Turtle Conservation and Protection, and the Memorandum of Understanding Concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa.
Long-term efforts to reduce or eliminate threats to Leatherbacks on nesting beaches have been successful (e.g. Dutton et al. 2005, Chacón-Chaverri and Eckert 2007, Sarti Martínez et al. 2007). Reducing Leatherback bycatch has become a primary focus for many conservation projects around the world, and some mitigation efforts are showing promise (Watson et al. 2005; Gilman et al. 2006, 2011). However, threats to Leatherbacks—bycatch and egg consumption and female exploitation, in particular, persist, and in some places, continue to hinder population recovery (Bellagio report 2007, Bal et al. 2007, Fretey et al. 2007, Alfaro-Shigueto et al. 2011, Wallace et al. 2013, Riskas and Tiwari 2013). For depleted Leatherback populations to recover, the most prevalent and impactful threats must be reduced wherever they occur, whether on nesting beaches or in feeding, migratory, or other habitats (Steering Committee, Bellagio Conference on Sea Turtles 2004; Bellagio report 2007; Wallace et al. 2011, 2013); a holistic approach that addresses threats at all life history stages needs to be implemented (Dutton and Squires 2011). Finally, high poverty levels in Africa place enormous pressure on sea turtle populations and would need to be recognized and addressed by conservation and management programs (Formia et al. 2003).
Alfaro-Shigueto, J., Mangel, J.C., Bernedo, F., Dutton, P.H., Seminoff, J.A. and Godley, B.J. 2011. Small-scale fisheries of Peru: a major sink for marine turtles in the Pacific. Journal of Applied Ecology 48: 1432-1440.
Amiteye, B.T. 2000. Distribution and some aspects of reproductive biology of sea turtles in Ghana. M.Sc. Thesis, University of Ghana.
Avens, L., Taylor, J.C., Goshe, L.R., Jones T.T. and Hastings, M. 2009. Use of skeletochronological analys to estimate the age of leatherback sea turtles Dermochelys coriacea in the western North Atlantic. Endangered Species Research 8: 165-177.
Bal, G., Breheret, N. and Vanleeuwe, H. 2007. An update on sea turtle conservation activities in the Republic of Congo. Marine Turtle Newsletter 116: 9-10.
Bellagio Report. 2007. Bellagio Sea Turtle Conservation Initiative: strategic planning for long-term financing of Pacific Leatherback conservation and recovery. Terengganu, Malaysia.
Blanc, J. 2008. African Elephant (Loxodonta africana). Available at: http://www.iucnredlist.org/details/12392/0. (Accessed: 21/09/2012).
Chacón-Chaverri, D. and Eckert, K.L. 2007. Leatherback sea turtle nesting at Gandoca Beach in Caribbean Costa Rica: management recommendations from fifteen years of conservation. Chelonian Conservation and Biology 6: 101-110.
Dutton, D.L., Dutton, P.H., Chaloupka, M. and Boulon, R.H. 2005. Increase of a Caribbean leatherback turtle Dermochelys coriacea nesting population linked to long-term nest protection. Biological Conservation 126: 186-204.
Dutton, P.H. and Squires, D. 2011. A holistic strategy for Pacific sea turtle conservation. In: P.H. Dutton, D. Squires and A. Mahfuzuddin (eds), Conservation and sustainable management of sea turtles in the Pacific Ocean, pp. 37-59. University of Hawaii Press, Honolulu, Hawaii.
Dutton, P.H., Roden, S.E., Stewart, K.R., LaCasella, E., Tiwari M., Formia A., Thomé J.C., Livingstone, S.R., Eckert, S., Chacón-Chaverri, D., Rivalan, P. and Allman, P. 2013. Population stock structure of leatherback turtles (Dermochelys coriacea) in the Atlantic revealed using mtDNA and microsatellite markers. Conservation Genetics 14(3): 625-636. DOI: 10.1007/s10592-013-0456-0.
Eckert, K.L., Wallace, B.P., Frazier, J.G., Eckert, S.A. and Pritchard, P.C.H. 2012. Synopsis of the biological data on the leatherback sea turtle (Dermochelys coriacea). U.S. Department of Interior, Fish and Wildlife Service, Biological Technical Publication BTP-R4015-2012. Washington, DC.
Formia, A., Tiwari, M., Fretey, J. and Billes, A. 2003. Sea Turtle Conservation Along the Atlantic Coast of Africa. Marine Turtle Newsletter 100: 33-37.
Fretey, J., Billes A. and Tiwari, M. 2007. Leatherback, Dermochelys coriacea, nesting along the Atlantic coast of Africa. Chelonian Conservation and Biology 6: 126-129.
Fretey, J., Segniagbeto, G.H. and Soumah, M. 2007. Presence of sea turtles in traditional pharmacopoeia and beliefs of West Africa. Marine Turtle Newsletter 116: 23-25.
Gilman, E., Gearhart, J., Price, B., Eckert, S., Milliken, H., Wang, J., Swimmer, Y., Shiode, D., Abe, O., Peckham, S.H., Chaloupka, M., Hall, M., Mangel, J., Alfaro-Shigueto. J., Dalzell, P. and Ishizaki, A. 2011. Mitigating sea turtle by-catch in coastal passive net fisheries. Fish and Fisheries 11(1): 57-88.
Gilman, E., Zollet, E., Beverley, S., Nkano, H., Davis, K., Shiode, D., Dalzell, P. and Kinan, I. 2006. Reducing sea turtle by-catch in pelagic longline fisheries. Fish and Fisheries 7: 2-23.
Godgenger, M.-C., Bréheret, N., Bal, G., N’Damité, K., Girard, A. and Girondot, M. 2009. Nesting estimate and analysis of threats for Critically Endangered leatherback Dermochelys coriacea and Endangered olive ridley Lepidochelys olivacea marine turtles nesting in Congo. Oryx 43(4): 556-563. doi: http://dx.doi.org/10.1017/S0030605309990329.
Gomez, J. 2001. Marine turtles in Ivory Coast (West Africa). In: M.S. Coyne and R.D. Clark (eds), 21st Annual Symposium on Sea Turtle Biology and Conservation NMFS-SEFSC-528 180-182. Philadelphia, Pennyslvania.
IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. IUCN, Gland, Switzerland and Cambridge, UK.
IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.2). Available at: http://www.iucnredlist.org. (Accessed: 13 November 2013).
IUCN Standards and Petitions Subcommittee. 2011. Guidelines for Using the IUCN Red List Categories and Criteria, Version 9.0 (September 2011). Available at: http://www.iucnredlist.org/documents/RedListGuidelines.pdf.
Jones, T.T., Hastings, M.D., Bostrom, B.L., Pauly, D.P. and Jones, D.R. 2011. Growth of captive leatherback turtles, Dermochelys coriacea, with inferences on growth in the wild: Implications for population decline and recovery. Journal of Experimental Marine Biology and Ecology 399: 84-92.
Mrosovsky, N. 2003. Predicting extinction: fundamental flaws in IUCN’s Red List system, exemplified by the case of sea turtles.
National Research Council (NRC) of the National Academies, USA. 2010. Assessment of sea turtle status and trends: Integrating demography and abundance. The National Academies Press. Washington, DC.
Rader, H., Mba, M.A.E., Morra, W. and Hearn, G. 2006. Marine turtles on the southern coast of Bioko Island (Gulf of Guinea, Africa), 2001-2005. Marine Turtle Newsletter 111: 8-10.
Riskas, K.A. and Tiwari, M. 2013. An overview of fisheries and sea turtle bycatch along the Atlantic Coast of Africa. Munibe monographs, Nature series 1: 71-82.
Sarti Martínez, L., Barragán, A.R., Muñoz, D.G., García, N., Huerta, P. and Vargas F. 2007. Conservation and biology of the leatherback turtle in the Mexican Pacific. Chelonian Conservation and Biology 6: 70-78.
Seminoff, J.A. and Shanker, K. 2008. Marine turtles and IUCN Red Listing: A review of the process, the pitfalls, and novel assessment approaches. Journal of Experimental Marine Biology and Ecology 356: 52-68.
Spotila, J., Dunham, A., Leslie, A., Steyermark, A., Plotkin, P. and Paladino, F. 1996. Worldwide population decline of Dermochelys coriacea: are leatherback turtles going extinct? Chelonian Conservation Biology 2(2): 209-222.
Steering Committee, Bellagio Conference on Sea Turtles. 2004. What Can be Done to Restore Pacific Turtle Populations? The Bellagio Blueprint for Action on Pacific Sea Turtles. World Fish Center, Penang, Malaysia.
The State of the World’s Sea Turtles (SWOT) Scientific Advisory Board. 2011. Minimum Data Standards for Nesting Beach Monitoring. Technical Report.
Tomás, J., Godley, B.J., Castroviejo, J. and Raga, J.A. 2010. Bioko: critically important nesting habitat for sea turtles of West Africa. Biodiversity and Conservation 19(9): 2699-2714. doi:10.1007/s10531-010-9868-z.
Turtle Expert Working Group (TEWG). 2007. An assessment of the leatherback turtle population in the Atlantic Ocean. NOAA Technical Memorandum NMFS-SEFSC-555.
Wallace, B.P., DiMatteo, A.D., Bolten, A.B., Chaloupka, M.Y., Hutchinson, B.J., Abreu-Grobois, F.A., Mortimer, J.A., Seminoff, J.A., Amorocho, D., Bjorndal, K.A., Bourjea, J., Bowen, B.W., Briseño-Dueñas, R., Casale, P., Choudhury, B.C., Costa, A., Dutton, P.H., Fallabrino, A., Finkbeiner, E.M., Girard, A., Girondot, M., Hamann, .M, Hurley, B.J., López-Mendilaharsu, M., Marcovaldi, M.A., Musick, J.A., Nel, R., Pilcher, N.J., Troëng, S., Witherington, B. and Mast, RB. 2011. Global conservation priorities for marine turtles. PLoS ONE 6(9): e24510. doi:10.1371/journal.pone.0024510.
Wallace, B.P., DiMatteo, A.D., Hurley, B.J., Finkbeiner, E.M., Bolten, A.B., Chaloupka, M.Y., Hutchinson, B.J., Abreu-Grobois, F.A., Amorocho, D., Bjorndal, K.A., Bourjea, J., Bowen, B.W., Briseño-Dueñas, R., Casale, P., Choudhury, B.C., Costa, A., Dutton, P.H., Fallabrino, A., Girard, A., Girondot, M., Godfrey, M.H., Hamann, M., López-Mendilaharsu, M., Marcovaldi, M.A., Mortimer, J.A., Musick, J.A., Nel, R., Pilcher, N.J., Seminoff, J.A., Troëng, S., Witherington, B. and Mast, R.B. 2010. Regional Management Units for marine turtles: A novel framework for prioritizing conservation and research across multiple scales. PLoS ONE 5(12): e15465. doi/10.1371/journal.pone.0015465.
Wallace, B.P., Kot, C.Y., DiMatteo, A.D., Lee, T., Crowder, L.B. and Lewison, R.L. 2013. Impacts of fisheries bycatch on marine turtle populations worldwide: toward conservation and research priorities. Ecosphere 4: 1-19. doi:10.1890/ES12-00388.1.
Watson, J.W., Epperly S.P., Shah A.K. and Foster D.G. 2005. Fishing methods to reduce sea turtle mortality associated with pelagic longlines. Canadian Journal of Fisheries and Aquatic Sciencies 62: 965-981.
Witt, M.J., Baert, B., Broderick, A.C., Formia, A., Fretey, J., Gibudi, A., Mounguengui, G.A.M., Moussounda, C., Ngouessono, S., Parnell, R.J., Roumet, D., Sounguet, G.-P., Verhage, B., Zogo, A. and Godley, B.J. 2009. Aerial survey of the world’s largest leatherback turtle rookery: a more effective methodology for large-scale monitoring. Biological Conservation 142: 1719-1727.
Witt, M.J., Bonguno, E.A., Broderick, A.C., Coyne, M.S., Formia, A., Gibudi, A., Mounguengui, G.A.M., Moussounda, C., Nsafou, M., Nougessono, S., Parnell, R.J., Sounguet, G.-P., Verhage, S. and Godley, B.J. 2011. Tracking leatherback turtles from the world's largest rookery: assessing threats across the South Atlantic. Proceedings of the Royal Society Series B 278(1716): 2338-2347. doi: 10.1098/rspb.2010.2467.
Zug, G.R. and Parham, J.F. 1996. Age and growth in leatherback turtles, Dermochelys coriacea (Testudines: Dermochelyidae): A skeletochronological analysis. Chelonian Conservation and Biology 2(2): 244-249.
|Citation:||Tiwari, M., Wallace, B.P. & Girondot, M. 2013. Dermochelys coriacea (Southeast Atlantic Ocean subpopulation). The IUCN Red List of Threatened Species 2013: e.T46967848A46967852.Downloaded on 19 October 2017.|
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