Remote sensing application for Sardinella lemuru assessment: a case study of the south waters of Malang Regency, East Java']Java, Indonesia

The assessment of lemuru fish (Sardinella lemuru) using remote sensing and Geographical Information System (GIS) has provided preliminary information on the habitat of lemuru fish at the South waters of Malang Regency, Indonesia. Lemuru fish catch data, mangrove mapping, Sea Surface Temperature (SST) and chlorophyll-a concentration derived from MODIS/Aqua images have been used in this study. The average of SST during the study was 26.1 degrees C, the highest average was on December and August was the lowest. The average of chlorophyll-a concentration was 0.55 mg/m(3), July was the highest and the lowest concentration of chlorophyll-a was on March. Most of the lemuru fish migrated to the west part of Malang waters during northwest monsoon (December-February), and moved toward eastern part during transitional (March-April-May). In contrast, on the southeast monsoon (June - August), lemuru spread across Malang waters. Habitat suitability of lemuru around coastal waters of Malang Regency related to their migration has different criteria for each month depend on the oceanographic factors and primary productivity. Based on the levels of habitat suitability, lemuru predicted to spawn on June. Sumbermanjing area was the most suitable area (72.39%). Lemuru moved away from Malang waters during transitional until the beginning of northwest monsoon. Primary productivity in coastal waters around Sumbermanjing increased in the southeast monsoon. It represented by January (0.7 mg/m(3)) in the northwest monsoon and increased reaches 3 mg/m(3) in the southeast monsoon on July. It was followed by the increasing of lemuru catch.