CRAB PREDATION ON GREEN TURTLE (CHELONIA MYDAS) EGGS INCUBATED ON A NATURAL BEACH AND lN TURTLE HATCHERIES

Abstract

A study of crab predation on green turtle (Chelonia mydas) eggs 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 beach and hatcheries and to determine the effectiveness of plastic mesh fencing for preventing crab predation. A total of 658 nests comprise of those on natural beach (214), hatcheries (429) and experimental plot (15) were investigated. Result showed 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 0.5 cm meshed plastic netlon to fence surrounding nests down to 1m deep under sand surface was proven effective in preventing crabs from entering the nests in turtle hatcheries. This preventive method was recommended for adoption in the operation of turtle hatcheries, as it was effective and eco-friendly sound.