Variabilitas musiman dan antar tahunan salinitas permukaan laut jawa serta implikasinya terhadap hasil tangkapan ikan pelagis kecil

Abstract

The monthly average of sea surface salinity (January 1994–December 2010 with a spatial resolution of 1o x1o) from Estimating Circulation and Climater of Ocean (ECCO) Dataset is used as a primary data, Dataset of wind (European Center For Medium Range Forecast, ECMWF) as a secondary parameter (monthly averages both for east-west (zonal) component and north-south (meridional) component, it is derived from 10 meters above sea level within period of January 1994–December 2010, with a spatial resolution of 2.5o x 2.5o) in this study. Time series analysis is conducted to obstain a complete picture of the Sea Surface Salinity (SSS) seasonal fluctuations. Results showed that SSS in the Java Sea has seasonal variability, which is shown by appearences of two SSS maximum and two SSS minimum annually. Based on monthly average in the northern part of Java Seas, the SSS is having range of 32 and 34,4 psu. In the first transitional season (March-April-May), SSS is relatively lower than the other season, i.e. NW monsoon, SE monsoon. The second transitional season (September-October-November), where it is found a low core SSS consentrated in the western part of the Java Sea and also in the south of Makassar strait. Results of the analysis shows that the catch varies according to temporal (monthly, seasonal, and annual), and to spatial in the Java Sea during the period 1990 to 1995. In the Java Sea, there are seven fishing ground of small pelagic fish, namely in the waters of north Pekalongan-Tegal, Java Karimun Islands, Bawean Island, Masalembo-Masalima Island, Matasiri Island, the southern Makassar Strait, and on the Kangean Island. Based on the total catch from the of seven regions, the average monthly percentage of the catch of round scads (Decapterus spp.), mackerels (Rastrelliger kanagurta), flat sardinella (Sardinella spp), round sardinella (Sardinella lemuru), bigeye scads (Selar crumenophthalmus), and yellowstripe scads (Selaroides leptolepis) are 48.50%, 16.97%, 14,15%, 10.80%, 8.65% and 0.93% respectively.