Loggerhead Turtles, Caretta caretta, at Dalyan Beach, Turkey: Nesting Activity (2004-2005) and 19-year Abundance Trend (1987-2005)

The nesting biology of loggerhead turtles, Caretta caretta, on Dalyan beach, Turkey, was studied during the 2004 and 2005 nesting seasons. In addition, we analyzed nesting trends over 19 consecutive years, from 1987 to 2005. A total of 711 emergences occurred in 2004 and 605 emergences in 2005, of which 223 (31.4%) and 221 (36.5%) nests were deposited, respectively. Mean nesting densities were 47.5 nests km(-1) and 47 nests km(-1) in 2004 and 2005, respectively. Of the overall nests, 424 (95%) were excavated and 32,339 eggs were counted. Of these eggs, 19,947 (61.7%) hatchlings had come out and 18,607 (93.3% of hatchlings) of them were able to reach the sea. We recorded a total of 3688 nests on Dalyan beach during 19 consecutive years with a mean of 194 nests per year. There were also strong annual fluctuations in the number of nests, which ranged from a minimum of 57 nests (in 1990) to a maximum of 286 (in 2002). No trend in the number of nests over the 19-year period was seen (95% CI -2.7% to 6.7% change per year). The lack of increase was a surprising result when considering the long-term conservation efforts on the beach; although, a similar case was reported in Laganas Bay, Greece. High interannual fluctuations could obscure trends as stated in previous studies.