Fang und Handel der aquatischen Schildkröten in Zentral Kambodscha
Harvest and trade of turtles from the Tonlé Sap Biosphere Reserve in central Cambodia
Cambodia is inhabited by 14 species of freshwater turtles and tortoises. The majority of these species are currently threatened by extinction due to overexploitation. Management for turtles in Cambodia includes the designation of protected areas and restrictions on the capture of imperiled species, but these efforts are presently hindered by unclear rules, poor enforcement and limited monitoring of harvest and trade. The Tonlé Sap Biosphere Reserve (TSBR) in central Cambodia comprises vast permanent and seasonal freshwater habitats, harbors at least seven freshwater turtle species and is considered an area of utmost importance for regional turtle conservation. In July 2014, we quantified the exploitation of freshwater turtles in the vicinity of Prek Toal Core Area, a portion of TSBR designated as fully-protected, and subsequently evaluated the sustainability of this collection. We conducted interviews with local people and directly monitored the harvest and trade of turtles in villages adjacent to the protected area and in the nearby town of Siem Reap. Encountered turtles were identified to species and basic demographic data were recorded. Statistical tests were performed to analyze the data and the results were then evaluated for indications of change in the local abundance of turtles. Substantial exploitation of turtles was found in both the villages and Siem Reap. Species composition of the trade did not differ significantly between the locations. Although four species were traded, the Mekong Snail-eating Turtle (Malayemys subtrijuga) was by far the most highly exploited. Other species documented in the trade were the Elongated Tortoise (Indotestudo elongata), Yellow-headed Temple Turtle (Heosemys annandalii), and Southeast Asian Box Turtle (Cuora amboinensis). The sex ratio of traded M. subtrijuga did not significantly differ from 1:1 and the body size distributions of both sexes were highly skewed towards smaller individuals. During interviews, local people reported that turtles, especially large individuals, are now less abundant and greater effort is required to locate them than in the past. As a result, searching specifically for turtles is currently perceived as unprofitable and most turtle collection at the present appears to occur incidentally to other fishing. While the continuing turtle harvest demonstrates that turtles still occur in the vicinity of Prek Toal Core Area, we found several indications that past capture levels have negatively impacted turtle populations in the area. As recovery of turtle populations in the face of intense exploitation is unlikely, we consider the current turtle harvest and trade in this portion of TSBR to be unsustainable.