Crab predation on green turtle (Chelonia mydas) eggs incubated on a normal beach and in turtle hatcheries

Ali A, Ibrahim K

In Proceedings of the 3rd Workshop on SEASTAR2000
Published 2002

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Abstract/Synopsis A study of crab predation on green turtle (Chelonia mydas) was conducted on a natural beach of Mak Kepit, Pulau Redang and at turtle hatcheries in Geliga and Chendor during March - September 2002. The objectives were to quantify crab predation on turtle eggs on natural beaches and hatcheries and to determine the effectiveness of plastic mesh fencing for preventing crab predation. A total of 658 nests comprise those on natural beaches (214) hatcheries (429) and experimental plot (15) were investigated. Results show that mortality of green turtle eggs in the study area due to ghost crab predation is not an important threat as the magnitude of depredation was only 1.3% (range 0.4 - 2.7%). Two species of crabs (i.e. Ocypode ceratophthalmus and Ocypode kuhlii) were recorded. The use of 0.5cm plastic meshed netlon to fence the surrounding nests down to 1m deep under sand surface was proven effective in preventing the crabs from entering the nests in turtle hatcheries. This preventative method was recommended for adoption in the operation of turtle hatcheries, as it was effective and eco-friendly sound.