Five hundred baby giant clams nurtured on Gaya Island, off the coast of Kota Kinabalu, were recently released into a selected ocean nursery in a bid to restore the marine ecosystem, writes Sushma Veera
IT was an emotional moment for the Marine Ecology Research Centre last month. Though its staff and marine biologists were diligently explaining to visitors any query they had on marine life or gladly posing for photographs when asked to, sadness was evident in their eyes. That was because they were preparing to release 500 baby giant clams into the ocean nursery on that morning of March 30.
After four years of hard work and dedication carefully nurturing the baby giant clams at the centre, the marine biologists would now reintroduce these clams in a selected ocean nursery.
The MERC is located above the turquoise waters of Gaya Island, a 15-minute boat ride from Kota Kinabalu. It is affiliated with the Gayana Eco resort. The release of the 7.6cm-long baby giant clams was part of its month-long awareness campaign Save The Giants, which kicked off on March 22.
MARINE CLEANING AGENT
Of the eight species of giant clams in the world, seven are found in our waters. Two species, Tridacna gigas and Tridacna derasa, are classified as locally extinct due to overharvesting. Giant clams are listed as Vulnerable by the Convention On International Trade In Endangered Species Of Wild Fauna And Flora.
Giant clams play an important role in the marine ecosystem. They filter wastes at the bottom of the sea and, in turn, improve underwater conditions for marine life.
MERC project director Alvin Wong points out that the giant clam doesn’t have a strong defence system and breeds slowly. Its population has reduced rapidly due to overharvesting for its meat and shell, as well as water pollution, urban development and unsustainable fishing.
Enter the MERC’s giant clam propagation programme. The first phase is the spawning process.
Wong explains: “Mature giant clams are induced (by injection of chemicals) to release their eggs and sperms for reproduction to take place. Plankton is cultured to feed the tiny hatchery-bred clams. A week later, the larvae will settle on a spot to grow before they are transferred to settlement tanks.”
Then it's a long wait of up to four years for the clams to grow large enough before they are released into the ocean to survive on their own.
As the largest bivalve molluscs typically have a low survival rate of 2 per cent when transplanted, Wong says it wasn’t easy to grow the 500 baby giant clams to their current size.
“These clams, each three inches (7.6cm) long, will be placed at a depth of 6m within the resort’s vicinity for close monitoring. We chose giant clams for our awareness programme as they are an endangered species with a low regeneration rate. Hopefully, this first batch will make it,” says Wong.
The clams are first released into a cage — to protect them from predators — until they grow bigger and can survive independently in the ocean. Once released, their progress will continue to be monitored by the MERC.
RAINFORESTS OF THE OCEAN
The MERC has also been cultivating corals for replanting. As many as 1,000 are ready to be transplanted in the surrounding waters of Gaya Island.
“Like the giant clams, live coral reefs are in serious danger of extinction due to sedimentation, bleaching caused by rising ocean temperatures and careless human activities,” says Wong.
The centre initiated a coral restoration programme that involves replanting broken coral fragments found within the vicinity of the Malohom Bay of the island.
“The focus is to give life to broken coral fragments that otherwise would have died if left on the seafloor due to lack of sunlight. By replanting the corals, we not only regenerate the reeds but also create a safe, natural habitat for the giant clams and other marine life,” explains Wong.
The coral fragments are first placed on specially prepared cement plates and left to stabilise at the centre's holding tanks for at least two weeks. They are then replanted in the surrounding reefs and monitored in a protected environment.
Visitors to the centre can also take part in coral replanting: They can adopt a coral they had planted and receive periodic data on its progress.
It all began about five years ago, when the Tan family took over the resort. They upgraded the research centre before starting work on the resort.
Owner Gillian Tan says: “The idea for an eco resort stemmed from the research centre as we saw it as an opportunity to give back to nature. It's our commitment to restore the marine ecosystem.”
Having successfully produced about 2,000 clams since the start of its programme, the centre is now ready to enter the next phase of its journey.
Wong says: “We don’t know if we will achieve our objectives, but now we want to celebrate the success of having gone through the first phase.
“We are both anxious and excited on the next step. The survival of the baby clams depends on many factors, like what the tide brings in.”
What if the next phase fails? “Then it'll be back to the drawing board.”
To cap off the month-long campaign, heartthrob singer-songwriter Ronan Keating will take part in a two-day celebration at Bunga Raya Island Resort & Spa on the other side of Gaya Island, this weekend. The former Boyzone frontman will perform at a dine-and-song event held exclusively for resort guests tomorrow.
Other performances include a beach Zumba dance session with fitness instructor Michelle Koh.