Endangered giant clam gets much-needed lift

Published July 23, 2021, 5:27 PM

by Manila Bulletin

First hatchery-bred giant clams in Palawan released into the wild at a special protection marine zone in Malampaya Sound in Taytay, Palawan on July 1, 2021. (Contributed photo/MANILA BULLETIN)

The Philippines’s true native giant clam species, scientifically called the Tridacna gigas, is about to get a needed lift to get it out of local extinction.

Led by the Malampaya Foundation, Inc. (MFI), several groups have banded together to ramp up catalytic restocking of the said species in effectively managed marine-protected areas (MPA’s) in Northern Palawan and Verde Island Passage.

Tagged as the String of Pearls project, the initiative aims to help revive the natural stocks of giant clams, abalone, and top shell in select Philippine reefs through marine restocking in partnership with the Western Philippine University (WPU), the Palawan State University, the Bureau of Fisheries and Aquatic Resources, Department of Environment and Natural Resources and the Palawan Council for Sustainable Development.

In 2012, MFI partnered with the WPU to help improve the hatchery production of abalone and topshell juveniles to catalyze trial culture as potential livelihood for fisherfolks and stock enhancement in MPAs.

The work evolved as the String of Pearls Project when giant clams were added as focal species thru the guidance of the late MFI Trustee and National Scientist Dr. Edgardo Gomez. In 2017, after a lead from WPU, five breeders of Tridacna gigas were confirmed by Dr. Gomez as Philippine-native. Declared to be locally-extinct since the 1980s, the five healthy clam breeders have been thriving well under the care of a private resort in Honda Bay, Puerto Princesa, Palawan.

Due to its low population and survival rate of less than 1% in the wild, the Philippine-native Tridacna gigas species is hard to propagate thus the need for hatchery facilities.

Upon reaching the size of a thumbnail (~20mm), the baby clams are transferred to nursery sites in the wild and kept for 8 months to a year before the larger individuals (>20cm) are carefully selected and released into the wild.

MFI and its partner institutions and representatives from the private resort spearheaded the first in-situ spawning of the clam species to help increase their number. The hatchery facility of the WPU in Binduyan, Puerto Princesa City houses majority of the activities for the String of Pearls Project. As of February 2021, a total of 2,300 clams have been restocked in various MPAs in Northern Palawan.

“We at MFI, together with our advocacy partners, envision a wider distribution of the Philippines’ true native giant clam Tridacna gigas throughout the country’s protected reefs by 2025. With the continued protection of restocked reefs in effectively-managed MPAs, the Philippines’ true native giant clam Tridacna gigas may come out of extinction status in 15-20 years,” said MFI Executive Director
Karen Agabin.

The Philippines’ marine biodiversity provides a plethora of benefits for Filipinos including food, medicine, livelihood, and oxygen. However, over the last few decades, there have been many problems facing the country’s marine ecosystems including pollution, decline in fish catch rates, coral reef bleaching, and habitat alteration.

MFI has been helping establish, expand, and manage over 335,000 hectares of marine-protected areas (MPAs) and marine management zones with communities, local governments, and national agencies in Palawan, Batangas, and Oriental Mindoro since 2013.

“This has been one of our major investments,” Agabin said. “There is a stark contrast between poorly-managed reefs and properly-managed MPAs. If effectively managed, MPAs can help accelerate the restoration and sustainable use of coastal and marine resources. They can also help regenerate and rebound fisheries of the country,” she further emphasized.