Dwindling numbers of turtles in Malaysia raise concern

The Star 24 Apr 10;

MALACCA: The east coast shores of Malaysia is the landing spot for four of the seven turtle species in the world, including the biggest one — the Leatherback (Dermochelys coreacea).

The other three are the Greenback (Chelonia mydas), Hawksbill (Eratmochelys imbricata) and Olive Ridley (Lepidochelys Olivacea).

The head of the Hawksbill Turtle and Sea Terrapin Conservation for WWF in Malacca, Lau Min Min said turtles played a significant role in maintaining the marine ecological balance.

He cited as example the Leatherback which fed on jellyfish, thus helping to control the jellyfish population.

This was because jellyfish ate fish eggs and a rise in jellyfish number could reduce the fish population, he said.

The other turtles too have a role. Among others, said Lau, the Hawksbill ate sea sponges that were present in the reef ecosystems. The sea sponges compete with other corals for space, and they protect themselves with sharp and poisonous spines.

“As such, the Hawksbill’s diet helps to keep the balance in the reef ecology. Fish can feed on the sponges after the turtle devours the spiky surface of the sponge.

“In the absence of the Hawksbill, the sea sponges will spread aggressively and eliminate the diversity of the reefs that provide food and shelter for marine life,” he explained.

Most importantly, he said, the turtle served as an indicator species where its presence or disappearance indicate changes in the environment.

The Turtle and Marine Ecosystem Centre (Tumec) research officer in Rantau Abang, Terengganu, Syed Abdullah Syed Abdul Kadir said that as the food chain within the marine ecosystem linked all marine organisms, when one member within the chain was missing the others would be affected as well.

“For example, the Olive Ridley feed on aquatic invertebrates (squids and jellyfish) while the Loggerhead Turtle feeds more on crustaceans (lobsters and crabs), jellyfish, sea sponge and soft coral on the sea bed.

“Their diet can help dictate the number and diversity of species in the shoreline ecosystem.

“Then there are turtles that feed on red algae which otherwise will spread and choke the reef ecosystem, which in turn will kill the fish population in that habitat.

“Also, the turtle’s soft shell provides shelter not only for other animals but also sea plants. A total of 100 types of marine animals and plants that survive on the shell have been recorded,” he said.

Even the turtle’s waste served as fertiliser for seaweeds and other marine plants, he added.

“It is obvious how the future of many species is strongly linked to the turtle’s survival. If the turtles become extinct, then the marine ecosystem will witness serious destruction.

“Humans will be affected because of the diminished fish population,” Syed Abdullah warned.

Dr Juanita Joseph, a researcher at Universiti Malaysia Terengganu’s Sea Turtle Unit (Seatru), said that although turtle conservation was started in the 1950s, the results were yet to be seen as it took between 25 and 50 years for turtles to mature.

“Seatru has been stepping up turtle conservation efforts in Pulau Redang since 1993. The turtle hatchlings that we released into the sea that year have yet to return,” she said.

She cautioned that Malaysia might one day witness the permanent loss of the Leatherback and the Olive Ridley if people and the authorities did nothing to protect them now.

“The Greenback and the Hawksbill still land here but their numbers have dwindled compared to the 1950s.

“Their dwindling numbers have been recorded in other countries as well but we hope that the conservation efforts will help reverse this trend,” she said. — Bernama