Analysis of oil sardine (Sardinella lemuru) fishing grounds in the Bali Strait waters, Indonesia

Abstract

Oil sardine (Sardinella lemuru) has an important economic value for the fishery sector in Indonesia. Until now the understanding of oil sardine fishing grounds is still limited. The present research aims to determine the composition of number and size of oil sardine, to determine the distribution of chlorophyll-a and sea surface temperature in the Muncar waters, Banyuwangi, and to evaluate the condition of fishing ground of oil sardine. Data were collected from fishing activities including time and locations of fishing, number and size of fish caught as catch recorded at each fishing location. Fish samples were randomly taken at each fishing location, and then their total body length was measured. Data of chlorophyll-a and sea surface temperature (SST) in the study sites obtained by processing images of SST and chlorophyll-a were detected by satellite Terra Aqua (MODIS). The study revealed that the catches were dominated by "protolan" group (size of 11–15 cm), only small fraction (21%) of fish with size of larger than 18 cm. In addition, it was found that the concentration of chlorophyll-a (0.126-0.259 mg m-3) in the Muncar waters and the Bali Strait affected the composition of oil sardine catches, while the sea surface temperature (SST) (27-30oC) did not have significant effect on the catch. Finally, potential fishing grounds for oil sardine in Muncar waters and the Bali Strait during periods of February-March 2015 were found only in the waters of Sembulungan, Pengambengan, and the Strait of Bali.