Kelimpahan dan Pola Distribusi Kerang Totok Geloina Erosa pada Kawasan Mangrove Segara Anakan Cilacap

The abundance and distribution patterns of a species in the ecosystem are determined by the degree of resource availability and the condition of physical and chemical factors that must be within the range that the species can tolerate. In detail, the abundance of organisms is the number of individuals in an area, whereas the distribution pattern is the spatial distribution of individual individuals to other individuals in the population. One species that live in the area of Segara Anakan Cilacap mangrove, which can be studied is Geloina erosa. This diminished abundance and erratic distribution pattern is problematic so research is done with the aim to find out the abundance and distribution patterns of G. erosa, and to analyze the dynamics of changes in G. erosa abundance and distribution patterns from 2015 to 2016. Sampling was conducted by survey on six stations, with purposive sampling method three times replicate size 1 x 1 m. Samples of G. erosa were inserted into the plastic and counted the number of individuals on each replication. The physical and chemical parameters measured are water temperature, water salinity, soil moisture, soil pH, and soil texture. The calculated G. erosa data is abundance, distribution pattern, and environmental factors. The results showed that the clustered distribution patterns exist at stations 1, 2, and 3 in 2015; and station 3 in 2016. Stations 4, 5 and 6 in 2015; as well as stations 1, 2, 4, 5, and 6 in 2016 can not be categorized as distributed because of the abundance of data does not exist. Changes in abundance and distribution patterns are marked by diminished abundance and uneven distribution patterns due to changes in environmental factors