Green Sea Turtle (Chelonia Mydas): a Historical Review With Relevance to Population Size in Sarawak

Abstract

Green sea turtles (Chelonia mydas) are using selected Sarawak sandy beaches for nesting. Its small-scale conservation efforts have started since the 1950s. However, the success of the effort is still debatable. Moreover, public participation in the conservation effort is still at an infancy stage. This study involved analysing nesting data of green turtles of Sarawak Turtle Islands (STIs) in terms of numbers of turtle landing, eggs collected, eggs incubated, and eggs hatched for Sarawak’s green turtle population from 1949 to 2016 with addition of estimation of the egg-laying females and their remigration interval. There was a sharp decline in terms of number of turtle landings from 1949 to the 1970s. The exact cause of this pattern could only be confirmed from old articles of historical value due to limited information on the events happening during those 30 years period. From 1980 to 2016, the annual nesting trend of turtles on STIs shows irregular fluctuation pattern and remigration interval of every 3 to 4 years with internesting frequency of 3. Turtle eggs were harvested annually, with a 36-year average of 223,558 eggs per year. Detailed analysis for data 1980 to 2016 shows that the lowest percentage of eggs incubated was in 1981 (20.4 %) and starting from the year 1991, egg incubation at STIs reached between 90 to 100 percent. There is an upward trend of egg hatching rate for the past 36 years, especially from the 1990s to 2000s, with the latest seven years average of 60%. The results imply that conservation of green turtle in Sarawak have been successful at different levels. However, there is still a need for relevant state agencies to modify and step-up efforts related to conservation of green turtles in Sarawak especially in terms of male:female ratio of hatchlings from STI’s hatcheries.