Mariculture of giant clam is primarily used to restock the coral reefs with giant clams by breeding and growing large numbers of juvenile giant clams. It also can become a source of giant clams for exports.
8 to 14 days after fertilisation of the giant clam’s gametes, its larvae would settle at the bottom of the tank. A year later, the juveniles would be transferred to ocean nurseries. Mesh cages are used to protect them from predators like turtles and rays. It is important to consider the site conditions and juvenile management practices to ensure a higher chance of survival of these cultured clams. You may have heard of how mariculture of other species could bring environmental degradation, but farming of giant clams does not. Their filter-feeding ability results in cleaner water leaving itself than the water supplied to them.
In the early 1980s, there was a joint effort within the Indo-Pacific countries to help with the declining giant clam populations issue. It was reported that there are currently 34 active giant clam hatcheries across 25 countries, with most being in Southeast Asia, such as Singapore, Thailand and Philippines.
As mariculture is one of the main methods to help with the populations of giants clams, it has been adapted in different ways and groups of people. You may click the following for examples or use the tabs to navigate:
- Research in Singapore (St John’s Island National Marine Lab)
- Corporate effort in the Philippines (Semirara Marine Hatchery Lab)
- Community effort in Thailand (Save Koh Tao)
Although mariculture is a good way to ensure that populations of giant clams do not decline and hopefully increase, high cost to sustain them in terms of time and money is an issue. In addition, cultured clams could result in low variability in their genes and possibly different from the ones in the wild. There is a higher chance of pathogen introduction in the hatchery as well. Research works in maricultural of giant clams would have to continue to create better and more sustainable mariculture technologies.
Watch a TED talk on Giant Clam farming by Dr. Gerald Heslinga, the father of giant clams mariculture.