The distribution of peanut-worm (Sipunculus nudus) in relation with geo-environmental characteristics

Abstract

Quang Ninh Province, situated in Northeast coast of Vietnam, has about 250km of shoreline, many estuaries, and tidal flats and over 2000 islands. The diversified nature, natural landscapes and ecosystems grant the province a great potential for tourism and specially seafood products. Peanut-worms (Sipunculus nudus) are exploited and used as popular seafood in international and domestic markets as special food of high nutritional and pharmaceutical value. According to the study results, peanut-worms live in unvegetative-cover sub-tidal flats, affected weakly by waves, wind and freshwater, submerged 10-18hours/day and environmental water is characterized by alkali - weak oxidized environment, high and stable salinity, low content of heavy metals. Beside, sedimentary environment is featured by high percentage of sand (more than 80%), alkali - weak oxidized environment, high nutrient and low heavy metals contents. Further more, the distribution of peanut-worms are strongly dependent on the following factors: sediment grain size, location and types of tidal flats, hydro-dynamic conditions, and environment parameters as pH, salinity and the dilution by freshwater. The research result can provide scientific background for sustainable coastal planning, natural resources management and identification of suitable zones for peanut-worm conservation and farming in the near future.