Photo credit: Kevin Fitzsimmons (USA)
Review: Abdel Rahman El Gamal (Founder of the website)
Introduction: Giant clams are marine bivalve molluscs in the family Cardiidae and sub-family Tridacnidae that are considered the largest bivalves in the world. Their large size, delicious taste and attractive shell colors have made them target animals for consumption and decorative purposes.
Threats: The strong demand on giant clam and their overfishing along with the degradation of their natural habitats have been responsible for stock depletion throughout much of their geographic range.
The desire to get quick and big harvests of the giant clams have been achieved through the use of special fishing boats with dredging techniques.
The danger of the over-fishing was even more dangerous when the clam hunting targeted the bigger and sexually mature animals. The late sexual maturity of the giant clams makes them highly vulnerable to stock depletion.
Conservation measures
Governing regulations: Due to the slow recovery from overfishing, giant clams are listed under Annex II of CITES (1983), and are considered vulnerable under the IUCN red list of threatened species (1996). Therefore, their collection, property, sale and export is prohibited. However, Because of the high price for clam-meat, the enforcement of such regulation is not as hoped and hence the violators continue their illegal fishing and trade.
Stock enhancement: The restocking programs of giant clams target to reinforce its stocks especially in the overfished places with the aim of re-establishing its populations.
The restocking activity usually begins at aquaculture facility in which the breeding takes place. Fortunately, Giant clams are not difficult to reproduce and culture. There are a number of hatcheries and grow-out operations have been established in the Indo-Pacific region. While such hatcheries can provide the giant clams juveniles for human consumption and/or aquarium trade, the hatchery produced juveniles could be utilized in the stock enhancement programs.
The photos are taken in a giant clam facility in Thailand. The first photo shows specimens of giant clams while the second photo shows the growing of giant clams as required for a stock enhancement program.
