A major concern for the horse’s hoof clam, and all giant clams, is consumption by locals. In the island of Kiribati, local folklore says that the fully grown clams leave their shells, turn into rays and swim away. This belief has caused fishermen to harvest giant clams before they are mature. Not only is the meat eaten, but the shell is used in a variety of ways (2), such as for tourist souvenirs (9). As giant clam numbers are depleted, the prices for them increase, leading to increased exploitation (2).
It is not certain whether exploitation is the cause of the horse’s hoof clam’s extinction in Tonga, Fiji and Samoa. However, those countries do have a history of overfishing other species of giant clams (10).
Like other giant clam species, the horse’s hoof clam may be particularly vulnerable to over-collection due to its late maturity, relatively short larval lifespan, and the ease with which it can be harvested from shallow reef habitats (11).