Impact of Oceanographic Variability on Chlorophyll-a Concentration and Sea Surface Temperature in North Maluku Waters and its Influence on Fish Abundance

The waters of North Maluku are rich in fisheries resources, which are important for the local economy and marine biodiversity. The variability of oceanographic conditions, such as chlorophyll-a and sea surface temperature, plays a significant role in determining fish abundance in this region. This study analyzes the seasonal variations of chlorophyll-a and sea surface temperature during 2021, as well as their impact on the productivity of the waters. Satellite imagery data of chlorophyll-a and sea surface temperature were analyzed using spatial interpolation. The results show seasonal fluctuations in chlorophyll-a concentration and sea surface temperature, where higher chlorophyll-a concentrations support primary productivity and fish abundance during mid-year. The highest chlorophyll-a concentration occurred in June (0.212 mg/m³) and the lowest in February (0.103 mg/m³). The negative phase of the Indian Ocean Dipole (IOD) reduces upwelling intensity, decreases nutrient availability, and impacts the decline in primary productivity. The highest sea surface temperature was recorded in November (30.99°C) and the lowest in August (29.87°C). These oceanographic variations affect the availability of phytoplankton, which is crucial in the marine food chain, and have implications for sustainable fisheries management in North Maluku. The results of this study can also serve as a reference for fish distribution or abundance modeling, such as with the maximum entropy method, to better understand the factors influencing fish distribution patterns in the region.