HABITAT QUALITY MUD CRAB (Scylla serrata) IN MANGROVE ECOSYSTEM OF BINTAN BAY, BINTAN DISTRIC, RIAU ISLANDS

Mud crab ( Scylla serrata ) is one of small scale fisheries commodity that have high economic value and typically associated with good mangrove ecosystem . A habitat degradationwill cause a serious impact on the existence of mud crab population. The puropse of this study was to assess the ecological quality of mud crab habitat conditionon B intan B ay’s mangrove ecosystem . Ecological data collection was conducted by using plots line transect for mangrove and the mud carb data collection by using fishermen catch ( fisher based survey ) . The results showed the value of habitat quality index (HQI) of mud crab ( Scylla serrata ) ranged from 52-82 w hich mean in the “m oderate ” category (index value 43-66) and "good" (index value 67-90). It show ed that Bintan Bay’s mangrove e cosystems was good enough to support the viability of mud crab. Habitat quality had a linier impact on body weight gain ( R 2 = 99 . 7 8%) and carapace width ( R 2 =99 . 21% ) . This showed that higher the index value of habitat quality, the size of the body weight and carapace width will increases.  Keywords : Scylla serrata, habitat quality, ecology, mangroves, and Bintan Bay