Territory researcher on hunt for disappearing giant clam 

CDU PhD candidate Shane Penny

Indigenous rangers are working with Charles Darwin University PhD candidate Shane Penny to survey the Northern Territory’s coastline for the threatened giant clam.

Mr Penny said that only one species of giant clam was found in the NT, Tridacna squamosa (the fluted giant clam), which has an elaborately striped or spotted fleshy mantle, large leaf-like fluted ribs on its shell and can grow to almost half a meter.

“This species is protected from illegal trade under the Convention on International Trade in Endangered Species (CITES) and listed as ‘at risk’ or threatened on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.”

Mr Penny said that despite protection under international treaties, giant clams continued to be harvested and were rapidly becoming locally extinct near easily accessible sites, particularly in South-east Asia.

“Research on giant clams has been neglected in the NT, with only a dozen museum records and as yet undocumented traditional knowledge,” he said.

“Giant clams once occupied reefs as far west as Darwin Harbour, but more commonly in Popham Creek within Garig Gunak Barlu National Park on Cobourg Peninsula. The clams now appear to be extinct from some of these areas.”

Through his research Mr Penny said he hoped to find further clues into what has caused the disappearance of the giant clams in northern waters.

“We hope to establish the conservation status of giant clams in the NT by investigating aspects of the ecology, population genetics and Indigenous ecological knowledge,” he said.

“What we do know is that they are slow growing, with low reproductive success, which makes them susceptible to high rates of harvest or environmental disasters.”

Mr Penny will travel to Thailand next week to present his research to an international audience as part of the World Congress of Malacology 2010 in Phuket.

This project is in collaboration with NT Indigenous Ranger groups, Parks and Wildlife Rangers and community volunteers.