On the front line: integrated habitat mapping for olive ridley sea turtles in the southeast Atlantic
Article first published online: 31 JUL 2013
© 2013 John Wiley & Sons Ltd
Diversity and Distributions
Volume 19, Issue 12, pages 1518–1530, December 2013
How to Cite
Pikesley, S. K., Maxwell, S. M., Pendoley, K., Costa, D. P., Coyne, M. S., Formia, A., Godley, B. J., Klein, W., Makanga-Bahouna, J., Maruca, S., Ngouessono, S., Parnell, R. J., Pemo-Makaya, E., Witt, M. J. (2013), On the front line: integrated habitat mapping for olive ridley sea turtles in the southeast Atlantic. Diversity and Distributions, 19: 1518–1530. doi: 10.1111/ddi.12118
- Issue published online: 7 NOV 2013
- Article first published online: 31 JUL 2013
- Darwin Initiative. Grant Number: STO-08-01
- National Science Foundation
- University of California Santa Cruz
- Achievement Awards for College Scientists
- Steve Blank
- United States Fish and Wildlife Service
- U.S. Department of the Interior
- Kwanda Base. Grant Number: STO-08-01
- Disney Worldwide Conservation Fund. Grant Number: STO-08-01
- Centre for the Dynamics and Evolution of the Land-Sea Interface
- Friends of Long Marine Laboratory
- Society for the Study of Amphibians and Reptiles
- Marilyn Davis Memorial Scholarship
- UCSC Graduate Student Association
- Square's Landscaping and Kitchen Gardens, Inc
- ensemble ecological niche modelling;
- ocean fronts;
- spatial analysis
Knowledge and understanding of marine vertebrate spatial ecology are required to identify sources of threat and highlight areas for conservation. Olive ridley sea turtles Lepidochelys olivacea are in decline in some regions, and data for the Eastern Atlantic are sparse. Here, we seek to describe observed, and potential, post-nesting habitats for this species in the southeast Atlantic. We contextualize these with fisheries catch data to identify areas of potential threat from fisheries interaction for this species.
West coast of Africa, southeast Atlantic.
We tracked 21 female olive ridley turtles, from two nesting sites, between 2007 and 2010. We used ensemble ecological niche modelling, integrated with knowledge on the physical and biological oceanographic environment, to identify regions where environmental variables exist that may be critical in defining post-nesting habitats for this species. We further integrate fisheries catch data to contextualize potential threat from fisheries.
We describe key areas of observed, and potential, olive ridley turtle occurrence at sea, and reveal that there was considerable overlap of these conspecifics, from two distinct nesting regions, within the Angolan exclusive economic zone (EEZ). With the inclusion of fisheries catch data for the region, we highlight areas that have the potential for conflict with fishing activities known to result in bycatch.
This study demonstrates that it is imperative that marine conservation policy recognizes the spatial extent of highly migratory species with expansive ranges. It also highlights that deficiencies exist in current knowledge of bycatch, both in gear specificity and in catch per unit effort. With integration of vessel monitoring system (VMS) data and those on fisheries catch, knowledge and understanding of bycatch may be improved, and this will ultimately facilitate development of appropriate management strategies and long-term sustainability of fisheries and their supporting ecosystems.