Estimation of Potential Skipjack Tuna Fishing Ground Using MODIS Data in 2020–2021 (Case Study: Bali Strait)

The Bali Strait is a semi-enclosed water that connects the Bali Sea with the Indian Ocean. One group of fish commonly caught by fishermen in these waters is skipjack tuna (Katsuwonus pelamis). This study aimed to estimate the optimal potential skipjack tuna fishing ground in Bali Strait waters for 2020 and 2021 using oceanographic parameters, particularly chlorophyll-a, sea surface temperature, and depth, using remote sensing and geographic information system (GIS) technology to help fishermen increase their catch. The results showed that the position of the skipjack tuna habitat shows a spatial pattern that varies every month and is closely related to the monsoon. The total potential area in 2021 decreased when compared with 2020, which amounted to 41,616 km2, and it was found that the potential area for skipjack tuna fishing was well-formed in the west season (January, February, and December) and first transition season (March–May), while in the east season (June–August) the potential area for skipjack tuna fishing decreased significantly. However, Badan Pusat Statistik (BPS) data on skipjack tuna production shows that skipjack tuna catches in Banyuwangi increased rapidly by 3393 tons compared with 2020, which only received 284 tons. Similarly, Jembrana regency caught 1142 tons in 2021, but no results in 2020. This indicates that the large number of potential areas in 2020 was not followed by the large number of skipjack catches. This may be caused by other external factors that disrupt the production process, such as the COVID-19 pandemic, which disrupts the activities of fishermen.