Giant clam (Tridacna derasa): growth and survival in American Samoa
Ponwith BJ. 1990. Giant clam (Tridacna derasa): growth and survival in American Samoa. Department of Marine and Wildlife Resources. Pago Pago, American Samoa
Three species of giant clams present now with a fourth species locally extinct; one species introduced to enhance local resources; growth rates for outside and aquarium clams differed with clams outside growing much faster; mortality was similar between sites; causes of mortality different (outside primarily predation by people, octopus, and a gastropod; inside undetermined); primary problem with the project to reintroduce and enhance natural fisheries was theft of clams from grow-out sites; high snail mortality also an issue but now that clams being cleaned of snails regularly things are better; smaller clams more susceptible to snail predation; growth steady at about 5cm/year; high mortality challenges the possibility of clam aquaculture in American Samoa; suggests adding villages to prevent clam loss; continued monitoring to prevent snail damage also suggested; also suggests other methods for preventing mortality from the two main causes.