MEPS 337:231-243 (2007)  -  doi:10.3354/meps337231

Prey landscapes help identify potential foraging habitats for leatherback turtles in the NE Atlantic

Matthew J. Witt1, Annette C. Broderick1, David J. Johns2, Corinne Martin3, Rod Penrose4, Marinus S. Hoogmoed5, Brendan J. Godley1,*

1Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn TR10 9EZ, UK
2Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
3Department of Geographical and Life Sciences, Canterbury Christ Church University, Canterbury CT1 1QU, UK
4Marine Environmental Monitoring, Penwalk, Llechryd, Cardigan, Ceredigion SA43 2PS, UK
5Museu Paraense Emilio Goeldi/CZO/Herpetologia, Caixa Postal 399, CEP 66017-970 Belém, PA, Brasil
*Corresponding author. Email:

ABSTRACT: Identifying key marine megavertebrate habitats has become ever more important as concern increases regarding global fisheries bycatch and accelerated climate change. This will be aided by a greater understanding of the patterns and processes determining the spatiotemporal distribution of species of conservation concern. We identify probable foraging grounds for leatherback turtles in the NE Atlantic using monthly landscapes of gelatinous organism distribution constructed from Continuous Plankton Recorder Survey data. Using sightings data (n = 2013 records, 1954 to 2003) from 9 countries (UK, Ireland, France, Belgium, The Netherlands, Denmark, Germany, Norway and Sweden), we show sea surface temperatures of approximately 10 to 12°C most likely indicate the lower thermal threshold for accessible habitats during seasonal foraging migrations to high latitudes. Integrating maps of gelatinous plankton as a possible indicator of prey distribution with thermal tolerance parameters demonstrates the dynamic (spatial and temporal) nature of NE Atlantic foraging habitats. We highlight the importance of body size-related thermal constraints in structuring leatherback foraging populations and demonstrate a latitudinal gradient in body size (Bergmann’s rule) where smaller animals are excluded from higher latitude foraging areas. We highlight the marine area of the European continental shelf edge as being both thermally accessible and prey rich, and therefore potentially supporting appreciable densities of foraging leatherbacks, with some suitable areas not yet extensively surveyed.

KEY WORDS: Leatherback turtle · Dermochelys coriacea · Bergmann’s rule · Gelatinous prey · Climate change · Habitat preference · Jellyfish · Niche

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Supplementary appendices: Appendix 1 & 2, Appendix 3