The release of more than a dozen hawksbill turtles this past week, in waters off the coast of the city-state of Singapore, was extraordinary for several reasons.
Eight of the 3-year old turtles released with satellite transmitters affixed to their carapaces were actually the offspring of hawksbill turtles that had been sent from the Underwater World Singapore (UWS) aquarium to Japanís Port of Nagoya Public Aquarium (PNPA), in 1997 and 2002.
Since receiving the donated turtles, PNPA’s captive breeding programme has succeeded in producing hundreds of hawksbill hatchlings – thirteen of which were returned as juveniles to Singapore in May 2010, in preparation for the August release.
(Five of the turtles were only a year and a half old, and were not large enough to be fitted with satellite transmitters).
Apart from the fact that any release of hawksbill turtles is a relatively rare occurrence (see the IOSEA Satellite Tracking Metadatabase), the fact that these young animals were the progeny of captive-reared parents and were the object of an international exchange which returned them to their native waters, added to the uniqueness of the event.
Five mature hawksbill turtles, each weighing around 50-60 kg, that had been kept at UWS for fifteen years or more, were released at the same time. These were turtles that had been caught in nets, stranded or confiscated and handed over to the care of UWS. Based on other studies showing the successful adaptation of captive turtles to life in the wild, the experts on hand had no qualms about returning them to the sea.
Although they were flipper-tagged, the larger animals were not fitted with transmitters, so their precise movements will not be monitored – perhaps a missed opportunity to collect information on the survivorship and behaviour of once captive animals.
Big Sister Island, south of the mainland, was chosen as a release site because of its relative tranquility. Nonetheless, the massive container ships that passed by the island provided an impressive backdrop.
Hawksbill turtles have been known to nest in Singapore in the past, along the east coast and on the industrialized island of Jurong, but it remains an extremely rare event.
UWS still has a fairly large stock of sea turtles of various species in its collection. For its part, PNPA’s rare captive-breeding programme continues to provide a unique display for members of the Japanese public. PNPA has had more success breeding loggerhead turtles in captivity, with hatching success averaging around 60% over the last decade, while the success rate for hawksbills stands at only about 15%, on average.
Singapore’s Ministry of National Development was represented at the release event by Parliamentary Secretary, Dr Maliki Osman, who gave a speech reiterating Singapore’s commitment to biodiversity conservation. Representatives of PNPA and UWS were actively involved in the release, as were Dr. George Balaz and Marc Rice, from Hawaii, who provided technical support during the attachment of the satellite transmitters. School groups, environmental NGOs and media representatives were also present in ample number.
Unfortunately, Dr C.H. Diong, who has a long history of involvement in sea turtle conservation work in Singapore, was unable to attend because of another engagement.
The turtle release was preceded by a moderated forum held at Underwater World Singapore, which featured leading members of Singapore’s environmental community.
The presentations and stimulating discussion that followed offered some interesting insights into nature conservation in a highly urbanized environment.
* * * * *
One can always debate the conservation value and cost-effectiveness of initiatives that represent a major departure from in situ conservation. Having successfully demonstrated that sea turtles can be bred in captivity, it is understandable that PNPA would wish to ‘complete the circle’ by returning the offspring to the wild and to monitor their fate. Although no plans were announced to display the turtles’ movements in real time on the web – perhaps missing out on another public education / awareness opportunity – it is understood that the organizers are keen to present some preliminary findings to the Convention on Biological Diversity (CBD) conference in Nagoya, this coming October.
The event served as an occasion to sensitize Singaporeans – politicians, environmentalists, academics and the general public alike – about the marine biodiversity that is not too distant from their shores and certainly residing in the waters of many of the neighbouring countries that Singaporeans like to visit.
To the extent that this well-publicised event reminded them of their common responsibility to contribute to biodiversity conservation at home and abroad, it may have served a useful purpose. And, hopefully, the Government of Singapore will demonstrate its commitment in this regard more formally, by signing the IOSEA Marine Turtle MoU in the not too distant future.