BRITISH INDIAN OCEAN TERRITORY (BIOT) BIOT Dr Peter Richardson, Marine Conservation Society (MCS), UK BIOT MPA designated in April 2010. Approx. 545,000 km 2 Green turtle (Chelonia mydas): Estimated 400 800 females nested throughout Chagos Archipelago in the 1995/96 season. Population trends unknown. NESTING BEACH INFORMATION Mortimer JA, Day M (1999). Sea turtle populations and habitats in the Chagos Archipelago. Pages 159-172 in C.R.C. Sheppard, and M.R.D. Seaward (editors). Ecology of the Chagos Archipelago. Linnean Society Occasional Publications 2.
Photo: Damitha Hewavitharana Hawksbill turtle (Eretmochelys imbricata): Estimated 300 700 females nested throughout Chagos Archipelago in the 1995/96 season. Population trends unknown. Peros Banhos Atoll (Ei=22, Cm=69) Great Chagos Banks (Ei=10, Cm=215) Salomon Atoll (Ei=21, Cm=66) Egmont Atoll (Ei=20, Cm=33) Diego Garcia (Ei=39, Cm=30) Mortimer JA, Day M (1999). Sea turtle populations and habitats in the Chagos Archipelago. Pages 159-172 in C.R.C. Sheppard, and M.R.D. Seaward (editors). Ecology of the Chagos Archipelago. Linnean Society Occasional Publications 2. Body pit counts from Feb/March 2006 surveys (Mortimer 2007) Photo: Damitha Hewavitharana Mortimer JA (2007). Final report: status and conservation of nesting turtles in the Chagos Islands (BIOT). Marine Turtle Conservation Fund Award 98210-6-G073. Unpublished report to Multinational Species Conservation Fund. FORAGING HABITATS Egmont Atoll Extensive pristine reefs
Seagrass beds and algal communities distribution poorly understood. Limited leatherback bycatch records in pelagic. Photo: Seapics.com SATELLITE TRACKING INFORMATION GENETICS October 2012: Satellite tags deployed on 8 nesting green turtles with CCLs ranging from 101.5cm to 111.0 cm in order to determine migratory routes and foraging grounds (G Hays pers comm. 2012). Photo courtesy of Graeme Hays Diego Garcia Turtle Bay
Foraging juvenile and nesting hawksbill samples collected from sites in archipelago and included in analysis. Hawksbill turtles Nesting population in BIOT is likely a distinct stock. Foraging juvenile stock in BIOT and Seychelles is indistinguishable Seychelles is a major source rookery for foraging juveniles in both BIOT and Seychelles. Seychelles BIOT Photo: Viv and John Philips Mortimer JA, Broderick D (1999). Population genetic structure and developmental migrations of sea turtles in the Chagos Archipelago and adjacent regions inferred from mtdna sequence variation. In Ecology of the Chagos Archipelago, Sheppard CRC, Seaward MRD (eds). Linnean Society/Westbury Publishing: London; 184 194. Green turtles Genetic analysis of a few nesting greens showed they shared halpotypes with populations in eastern and western Indian Ocean. No analysis of green turtle foraging stock published to date. MAJOR THREATS Illegal fishing Sri Lankan fishers targeting sharks and sea cucumbers. BIOT fisheries patrols intercepted 12 vessels in 2010 and 12 vessels in 2011 (C. Mees pers comm. 2012)
Turtle take recorded at illegal fishing camps but full extent unknown. Mortimer JA (2007). Final report: status and conservation of nesting turtles in the Chagos Islands (BIOT). Marine Turtle Conservation Fund Award 98210-6-G073. Unpublished report to Multinational Species Conservation Fund. Limited leatherback bycatch observed in pelagic fisheries, all remaining licenses expired by 2010 (MRAG unpubl. data). Photo courtesy of NOAA Some atolls affected by shoreline erosion and marine debris, effects on nesting habitats poorly understood. Unquantified turtle egg and hatchling mortality by introduced mammals, especially cats and rats. Mortimer JA, Day M (1999). Sea turtle populations and habitats in the Chagos Archipelago. Pages 159-172 in C.R.C. Sheppard, and M.R.D. Seaward (editors). Ecology of the Chagos Archipelago. Linnean Society Occasional Publications 2. Sheppard, C et al. (2012) Reefs and islands of the Chagos Archipelago, Indian Ocean: why it is the world's largest no-take marine protected area. Aquatic Conservation: Marine and Freshwater Ecosystems. n/a-n/a. ISSN 1052-7613. NEW CONSERVATION INITIATIVES New Conservation and Management Plan for the Chagos MPA provides for continued turtle research and monitoring to be overseen by a UK Government-appointed Scientific Advisory Committee Photo: Sue Ranger/MCS
CONCLUSIONS E.g. ongoing monitoring and sampling by Dr Jeanne Mortimer, and new satellite tracking and nesting beach temperature monitoring by Prof. Graeme Hays at Swansea University, Wales (G Hays pers comm 2012). Work to date suggests that BIOT provides regionally important nesting and pristine foraging habitat for green and hawksbill turtles. The designation and management of the MPA has made a significant contribution to safeguarding the future of these populations and habitats. 98% of the Chagos Archipelago has not been surveyed Dr Mortimer has made great advances, but there is still much to learn! THANK YOU WIOMTTF Secretariat Workshop participants Dr. Peter Richardson Biodiversity Programme Manager Marine Conservation Society peter.richardson@mcsuk.org www.mcsuk.org