Titel: THE STAR (Petaling Jaya, Malaysia) ; Saving terrapins (Hilary Chiew) Bericht door: schildpaddennetcrew op 23 Juni 2008, 12:26:20 THE STAR (Petaling Jaya, Malaysia) 21 February 06 Saving terrapins (Hilary Chiew)
It was dark and rainy. And the river water was closing in on a river terrapin nest by the banks of Sungai Dungun, Terengganu. Dr Gerald Kuchling, a turtle expert from Australia, and villager Mohd Rosli Hamzah, were desperately trying to locate the eggs in the submerged nest. After struggling for an hour, the rescue operation was abandoned and four eggs were sacrificed. “I’m sorry. I cannot retrieve the rest,” said Kuchling dejectedly to Prof Chan Eng Heng, co-leader of the Sungai Dungun River Terrapin Conservation Programme. Due to continuous rain for the past 24 hours, the water level of Sungai Dungun has risen steadily and by 10pm on Feb 10, an area the size of two football fields on the sandbank called Pasir Kumpal has been inundated. Nest Number 2, located on the outer edge of the riverbank, was the first to be submerged and had to be rescued. Out of six eggs successfully excavated, three were broken. The clutch of 10 eggs deposited on Feb 1 was incubated in situ (in its original location) at Pasir Kumpal. The rescue operation was an unexpected turn of event for the team who were there to revive the conservation project carried out by the Department of Wildlife and National Parks (Perhilitan) between 1998 and 2001 on the highly endangered river terrapin (Batagur baska). Due to cutbacks in funding, the project had lapsed for four years. The field station was re-opened on Jan 26. Monitoring of turtle nesting and egg protection were carried out by two Perhilitan rangers and two hired villagers under the supervision of research assistant Wong Yun Yun. “We ended up literally saving the eggs from drowning. The flood was totally unexpected as February is the tail-end of the monsoon and the start of the nesting season,” said Chan,who set up the Turtle Research and Rehabilitation Unit to conserve the species in 2004. The Sungai Dungun programme is a collaboration between the unit of Kolej Universiti Sains dan Teknologi Malaysia (Kustem) and Perhilitan. The team also dug up another nest with six eggs. Both clutches of eggs were re-buried on higher ground but when the water encroached further inland the next morning, had to be removed again. The eggs, together with those from two other nests, were transferred into pails and stored in the female volunteers’ dormitory. The two researchers, two volunteers, The Star photographer and this writer were evacuated at 7pm as the water level rose to 39.12m, breaching the danger mark of 37.5m. Chan suspended the conservation effort until the water subsided. She returned to retrieve the eggs and field equipment two days later. Nesting of the river terrapin has been sparse thus far. Rosli said false crawls are common early in the two-month nesting season. It appears that the terrapins are sensitive to human movements on the sandbank. The monitoring work at Pasir Kumpal is modelled after a marine turtle conservation programme in Pulau Redang started by Chan in 1993. “Unlike the green turtle which allows us to monitor them up-close, the terrapins do not welcome any form of intrusion. There will trials and errors before we can establish a standard field procedure for the river terrapin,” she said. The scientist hopes to document nesting frequencies and microchip nesting females. These are vital information to revive the population that has declined by half over the last 14 years. Little scientific data is available on the terrapin, which is among the world’s 25 endangered tortoises and freshwater turtles. In Malaysia, the river terrapin can be found in several major river systems but decreased nesting has been reported from beaches monitored by Perhilitan. Perhilitan had established hatcheries in the late 1960s in Bota Kanan (Sungai Perak), late 1970s in Bukit Pinang (Sungai Kedah and Sungai Muda) and 1980s in Bukit Paloh (Sungai Terengganu and Sungai Dungun). In Terengganu, two other known populations at Sungai Besut and Sungai Setiu are not protected. Eggs were purchased from licensed egg-collectors or collected from beaches gazetted as sanctuaries by state governments. For the Sungai Dungun population where there are 13 nesting beaches, Perhilitan is protecting two major sites – Pasir Kumpal and Pasir Tok Chu. The larger Pasir Kumpal is a gazetted sanctuary. Although Pasir Tok Chu was left out, the locals have refrained from collecting the eggs as Perhilitan ran an in situ station there between 1998 and 2001. Prior to 1998, Perhilitan’s efforts were focused on ex-situ (off-site conservation) egg incubation, head starting and release of captive-bred animals. Between 1980 and 1999, it released 3,676 terrapins but this has not helped recover the population. Research by Chan and her research students in 2004 and 2005 yielded a population estimate of 76 individuals. “This cannot be considered a healthy population size. Protecting the premier nesting ground of Pasir Kumpal is crucial to saving this population. Half of the incubated eggs will be released upon emergence and the remaining will be head-started for a staggered release programme,” explained Chan of her strategies for Sungai Dungun. While widespread egg-consumption is a major threat to the terrapins’ survival, incidental capture in fishing gears resulting in drowning of the reptile is no less detrimental. Rosli has observed the deaths of three adult females since January. Chan said the negative impact of fishing on the terrapin needed to be assessed and destructive methods replaced with terrapin-friendly fishing gears. “Further ground observation in Dungun will help us to determine the home range and foraging areas of the terrapins. Although Pasir Kumpal is said to be the premier nesting site, we will investigate the other beaches too,” she said. Chan said the Sungai Dungun population is the most promising of the two rivers that she has studied. Sampling in Sungai Setiu indicated that the population is almost depleted. She initiated a recovery programme for Sungai Setiu in 2004, by purchasing eggs from villagers for ex-situ incubation at the Kustem campus. The effort rescued 646 eggs from human consumption in the last two years. One hundred year-old terrapins were released at Sungai Setiu last Aug 31, dubbed Terrapin Independence Day, which is set to become an annual event. Aware that she is racing against time to save the river terrapin, Chan hopes that with the co-operation of the authorities, the Sungai Dungun programme will be replicated at other rivers in Terengganu and other states. http://thestar.com.my/lifestyle/story.asp?file=/2006/2/21/lifefocus/13417677&sec=lifefocus THE STAR (Petaling Jaya, Malaysia) 21 February 06 Enhancing the reproduction process (Hilary Chiew) Dr Gerald Kuchling was looking forward to scanning a gravid river terrapin after lugging a 25kg ultrasound machine from Perth to Thailand and then to Terengganu over four weeks. Instead, he counted his blessings when he retrieved the RM45,600 machine in one piece from the flooded field station at Pasir Kumpal, two days after he was evacuated from the inundated site. The turtle reproductive expert from Australia was offering his expertise in ultrasound scanning to the Kolej Universiti of Sains dan Teknologi (Kustem) Turtle Research and Rehabilitation Unit. Since his arrival on Feb 8 however, he has not gotten any nesting female to scan. The technique, modified from the ultrasound-scanning machine used on pregnant women, was developed by the University of Western Australia researcher in 1987. It was instrumental in saving the western swamp tortoise from the brink of extinction. There were fewer than 50 individuals and the small number of females had not laid eggs for six years. Using the ultrasound, Kuchling found that the turtles lacked food supplies needed to mature their follicles. The problem was rectified. Subsequently, the tortoise (Pseudemydura umbrina) began laying eggs and to date, over 80 captive-bred youngs have been returned to the wild. The ultrasound method is now widely used in by turtle conservation programmes. It will allow the ovarian follicles to be counted and measured, enabling inferences on the clutches of egg which will be laid in the nesting season. Kuchling fears that artificial incubation of eggs by the Perhilitan captive-breeding centres over the years could have resulted in the release of sex-biased terrapins to the wild. He has visited Malaysia three times since 2004. During his first two trips, he imparted a sex-determination skill called laparoscopy, which involves insertion of an endoscope into the body cavity to determine the sex of the terrapin. He applied the technique to captive-bred terrapins at Perhilitan facilities in Bota Kanan in Perak and Bukit Paloh in Terengganu, as well as at Kustem’s project. “Different incubation techniques produced different sex ratios. Initial investigation showed that Perhilitan centres produced female-biased hatchlings,” he said, adding that further investigation is needed to understand the consequences of captive-breeding programmes. http://thestar.com.my/lifestyle/story.asp?file=/2006/2/21/lifefocus/13417680&sec=lifefocus |