Spatial and Temporal Variation of Biomass Blood Cockle (Anadara sp.) in Estuaries Dadapan, Sedati Sub-District, Sidoarjo, East Java

Biomass is one of the primary data in decreasing the quality and quantity of blood cockle because it can determine the constantly caught feathered shells that will run out of stock. Thus the temporal and spatial variation of the total value of the shell biomass will be connected whether it is related or not. Efforts to reduce the number of biomass is by catching fur shells in an area that many fishing activities conducted by fishermen. The catching activity is divided into three stations namely the river mouth distance of 1.5 km, 1.75 km and 2km. Spatially the total biomass of fur shells (Anadara sp.) Is at the mouth of the Dadapan river. Temporally the range of biomass at the mouth of the Dadapan river is greater in January at 1.75 km station of 11.53 gr/m², whereas biomass at 2 km station is 9,79 gr/m² and biomass at 1.5 km station 5.49 gr/m². The current velocity in January is 8-10 cm/sec, the wind velocity in January is 2-3 knots, and the wave height in January spreads from 1.76-0.81 meters. Current, wind and wave.