MTN 77:17-19 Marine Turtle Nesting In The GÖKsu Delta, Turkey, 1996

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MARINE TURTLE NESTING IN THE GÖKSU DELTA, TURKEY, 1996

A 1988 survey of the Turkish coastline revealed 17 areas to be important nesting sites for marine turtles, one of which is the region of the Göksu Delta (Baran and Kasparek, 1989). In 1990, this area was designated a Special Protection Area by the Turkish authorities. Subsequent surveys in 1991 (van Piggelen, 1993) and 1992 (Peters and Verhoeven, 1992) confirmed that these beaches support nesting by both loggerhead (Caretta caretta) and green (Chelonia mydas) turtles. Within the Mediterranean, this is one of the few sites, other than Cyprus, where both species nest.

During the period 19 June to 13 August 1996, students from the University of Glasgow monitored the beaches of the Göksu Delta every 7-10 days, completing a total of six surveys per beach (a similar methodology characterised the initial 1988 survey). Observers counted and identified tracks in order to record the distribution and number of nests of both species. Species identification was possible using criteria pertaining to track and nest pit morphology (Broderick and Godley, 1996). Whilst carrying out nesting surveys, potential threats to turtle and nest survival were assessed.

In 1996, as in previous years, Caretta dominated, but fewer nests were recorded than in 1991 or 1992 (see Glen et al., 1996, for details). The difference is likely due, in part, to the fact that the surveys in 1991 and 1992 (when beaches were monitored regularly for the full nesting season) were more comprehensive than the surveys in 1996 or 1988. It is possible, however, that these data reflect actual inter-annual variation in the number of nesting females. Relatively low nesting numbers of both species were also recorded in Northern Cyprus (Godley and Kelly, 1996) and at other sites in Turkey (Baran et al., 1996) in 1996.

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Species	1988	1991	1992	1996
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C. caretta	45	117	89	36
C. mydas	0	20	14	3
TOTAL	45	137	103	39

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Threats to sea turtles in the Göksu Delta include sand removal, beach inundation, high levels of nest depredation by canids, pollution, and human use of habitat largely related to tourism. Fifteen stranded turtle carcasses were recorded, 12 of which were juvenile C. mydas. Injuries sustained by most individuals suggested incidental catch in local longline and driftnet fisheries as the cause of mortality. No direct conservation action was undertaken as part of the 1996 survey effort, but participating Glasgow students met and exchanged methodologies with both Turkish and international volunteers working at other marine turtle monitoring and conservation projects at Kazanli, Anamur and Akyatan. These exchanges were beneficial to all concerned.

We recommend, based on the results of our field work and discussions with relevant authorities, that detailed ongoing surveys of marine turtle nesting be carried out to enable a more complete assessment of the importance of this area to marine turtles. In conjunction with these studies, the long term status of these populations would be improved by undertaking a programme of nest screening (to reduce the effects of predation) and strict enforcement of conservation laws afforded by the area's protected status. The Turkish authorities and the Society for the Protection of Nature (DHKD) should be applauded for the valuable inroads which have been made into conservation awareness in the region; we recommend that conservation awareness programmes continue, and that targeting fishermen be a priority.

Addendum: The authors have since been informed that DHKD intends to carry out detailed surveying of these beaches in tandem with local universities during the 1997 nesting season.

Acknowledgements: This project was largely supported by a grant from the British Council, Ankara. Accommodation was generously provided by the Institute of Marine Sciences, Middle Eastern Technical University. In addition we would like to thank Professors Ilkay Salihoglu and Umit Unluata of the Institute for their advice and support, Drs. Ali Cemal Gucu and Ahmet Kideys for their expert advice, and the rest of the staff and students for their help. Thanks also to all at DHKD, Tasucu for their collaboration over the years.

Baran, I. and M. Kasparek. 1989. Marine Turtles in Turkey: Status survey 1988 and Recommendations for Conservation and Management. WWF Publication.

Baran, I., O. Türkozan, Y. Kaska, Ç. Ilgaz and S. Sak. 1996. Research on the marine turtle populations of Dalyan, Fethiye, Patara and Belek beaches: Final Report. 44pp. Unpubl.

Broderick, A. C. and B. J. Godley. 1996. Population and nesting ecology of the green turtle, Chelonia mydas, and the loggerhead turtle, Caretta caretta, in Northern Cyprus. Zoology in the Middle East 13:27-46.

Godley, B. J. and A. Kelly. 1996. Glasgow University Turtle Conservation Expedition to Northern Cyprus 1996: Expedition Report. Department of Veterinary Anatomy, University of Glasgow Veterinary School. 23 pp. Unpubl.

Glen, F., B. J. Godley and A. Kelly. 1996. Marine turtle monitoring in Turkey by students from the University of Glasgow: A report to the British Council, Ankara. 14 pp. Unpubl.

Peters, A. and K. J. F. Verhoeven. 1992. Breeding success of the loggerhead, Caretta caretta, and the green turtle, Chelonia mydas, in the Göksu Delta, Turkey. Rapport 310. Department of Animal Ecology, University of Nijmegen, The Netherlands. 26 pp. Unpubl.

van Piggelen, D. C. G. 1993. Marine turtle survey in the Göksu Delta, Turkey, June - August 1991. Report 314. Department of Animal Ecology, University of Nijmegen, The Netherlands. 35 pp. Unpubl.

FIONA GLEN, BRENDAN J. GODLEY, ANDREW KELLY and ANNETTE C. BRODERICK, Division of Environmental and Evolutionary Biology, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, SCOTLAND.