The biomass, abundance, and distribution pattern of starfish Asterias sp. (Echinodermata: Asteroidea) in East Coast of Surabaya

This study aims to determine the biomass, density, and distribution patterns of Asterias sp. Samples were collected from three locations such as Wonokromo, Dadapan and Juanda, each divided into 3 zones. In each zone, samples were taken as many as 5 repetitions using swept area method. Temporarily, the highest biomass of starfish was 2.95 gr/m² in Dadapan Zone on January. Spatially, biomass of starfish was found in Dadapan Zone (3,35 gr/m²). Similarly, the high density was also found in Dadapan Zone on January (9 ind/10 m²). In general, the distributionpattern of starfish in East Coast Surabaya throughspatial and temporal showed that the pattern of starfish was grouping distribution (Id value > 1) for Dadapan and Juanda, and uniform for Wonokromo. Oceanographic condition, antropogenic activity, and water quality in East Cost of Surabaya become important things which is affected the biomass, densityand distribution pattern of starfish. The knowledge of starfish biomass and density is very important given that this biota has ecological value as a balancing ecosystem in the waters.