Bivalve Spat (Anadara granosa) recruitment in rehabilitation mangrove ecosystem of Rangsang Island, Riau province

Abstract

Southeast Asia's mangrove areas are inhabited by several bivalves, such as the blood clam (Anadara granosa), which are widely distributed in intertidal areas. The importance of economic value of bivalves causes the availability of seeds to be very important. Knowing the abundance and life cycle of bivalves (Anadara granosa) is the right step in estimating the ideal time to collect bivalves in an ecosystem. This study aimed to determine the abundance and time of attachment of bivalves (Anadara granosa) seeds in the rehabilitation mangrove ecosystem on Rangsang Island, Riau. The sampling method used is purposive sampling, consisting of two subzones, and each subzone is located in the intertidal zone, namely at the point of the highest tide and the highest low tide in the mangrove forest area. The results showed that A. granosa was more common in December (79100 ind/100 m2) with an average length of 7.67 (±3.94). The relationship between mangrove density and abundance of A. granosa has a strong relationship in December and January, with the length range of A. granosa being influenced (strong category) by pH and temperature.