SPECIES AND SYSTEM SELECTION FOR SUSTAINABLE AQUACULTURE IN THE REPUBLIC OF THE MARSHALL ISLANDS. CULTURE POTENTIAL OF PACIFIC CLAM OR JUKKWE Asaphis violascens (FORSSKÅL, 1775)

The Republic of the Marshall Islands, as other nations in the region are facing many severe upcoming challenges due to climate change. Coastal resources management are important issues in order to adapt to the increasing severity of this challenging changes. Aquaculture is a potential adaptation option to reduce the impacts on native populations.

Pacific clam or jukkwe, Asaphis violascens is a bivalve benthic species, found in lagoonal sand flats with a depth range between 0 - 20 m. It is the dominant, and often the only bivalve in this habitat. It is a suspension feeder, and is dioecious, the sexual maturity is reached at about 6 months with size ranging from 18-20 mm. It is considered a highly valued food species in the region. Archaeological research has demonstrated that Marshall islanders exploited this resource for subsistence and as raw material since colonization about 2000 years ago. Because they inhabit accessible zones it is a valuable resource for aquaculture of jukkwe clams could be an interesting option for improving household food security

The aim of this research is to develop the basic technology for culturing A. violascens in order to meet demand for seafood, food security and stock enhancement, encouraging and helping farmers and fishing communities to improve their socioeconomic condition supporting healthy ocean populations and ecosystems.

Several attempts to spawn A.  violascens were made. Eggs obtained from natural spawning after air drying clams for 2 hours during full moon were fertilized by exposure to dilute sperm suspension for 30 to 90 min at 28⁰C and S 33. Pediveliger larvae was observed on day 10 (170 - 180 µm). Two different growing trials were tested with wild clams, one at the laboratory with addition of microalgae cultures and the other at the natural habitat, keeping them in net bags at tidal areas. Results showed that the seed production in captivity is feasible, and that the grow on phytoplankton and detritus available is possible in a seawater system.