Composition, Density and Spatial Distribution of Zooplankton in Inner Ambon Bay, Indonesia
Inner Ambon Bay is part of Ambon Bay; it is semiclosed area and a small pelagic fish fishing ground, especially anchovy. The anchovy is a zooplankton predator; therefore the existence of anchovy is affected by the abundance of zooplankton. The aims of the research are to obtain information on the composition, density, and spatial distribution of the zooplankton in these waters. Data of zooplankton composition were obtained from sampling by using plankton net at ten observation stations. Meanwhile, data of densities were collected using a scientific hydroacoustic system, BioSonic DTX supported with splitbeam technology, on six parallel transect lines and one crossparallel transect line. Geostatistical analyses technique was used to describe horizontal distributions of zooplankton, and vertical distributions pattern were plot in the graphs. The result shows that the zooplankton community is dominated by Copepod and meroplankton. The highest average density was found in August (9393 ind./m2), while the lowest density was in June (903 ind./m2). Vertical distribution of zooplankton generally shows that the highest density was found nearsurface and decrease to the deeper water column, except in June and July, where the highest density of zooplankton was found at a depth of 37m and 17m, respectively. On the horizontal distribution, lower densities (5000 ind./m2) occupy smaller space.
