Prediction of potential fishing zones for mackerel tuna (Euthynnus sp) in Bali Strait using remotely sensed data

Abstract

Mackerel tuna (Euthynnus sp.) is one of the pelagic fish species that has become the export commodity of Indonesia. This species is a carnivorous marine biota that forms a group with rapid swimming abilities. Mackerel tuna is scattered throughout Indonesian waters, including the waters of the Bali Strait. This study aims to predict Mackerel tuna fishing zone in the Bali Strait by using remotely sensed data. Sea surface temperature (SST) and sea surface chlorophyll-a (chl-a) were downloaded from the ocean colour website meanwhile the fishing catches obtained from nusantara fisheries port (pelabuhan perikanan nusantara) Pangembangan, Bali and the fishing lane from marine research and observation agency (balai riset dan observasi laut), Bali. The results showed that the highest of fishing catches occurred in September and October with SST value of 26 – 28 °C and chl-a value of 0.4 – 2.6 mg/m3. Based on the SST and chl-a value, the results revealed the potential fishing zone of Mackerel tuna mostly occurred during south monsoon (April - September). In general, the distribution of Mackerel tuna, based on the overlaid SST and chl-a, showed moderate spatial correlation with actual fishing locations from local fisherman. Integration in situ data and oceanographic condition generated from remotely sensed data could form the basis for fisheries management and information system, such as Mackerel in Bali Strait.

Analysis of Sea Surface Temperature and Chlorophyll-A and Its Relationship with Catch Results Flying Fish Eggs in the Waters of the Kei Islands

“…The high chlorophyll-a content of a body of water can indicate that the water has a high level of fertility. (Syah et al, 2020), stated that chlorophyll-a is a factor that can provide a direct indication of the presence of fish food and pelagic fish migration routes. This is in line with the increase in chlorophyll-a concentration during the time (season) of catching flying fish eggs, where the highest chlorophyll-a concentration reached 3.09 mg/m 3 (2015), while the lowest value was 0.10 mg/m3 (2016).…”

Genetic Diversity and Population Structure of Bullet Tuna (Auxis rochei) from Bali and Its Adjacent Waters

“…According to Sastra et al (2018), the population of neritic tuna is widespread in almost all Indonesian waters, including Bali and its surrounding areas. The Bali Strait itself holds a potential supporting system of aquatic marine life for coastal fisheries communities (Syah et al 2020). Best scientific total catches estimation of bullet tuna from the Indian Ocean in 2019 reaching 24,000 tons with an average (2015-2019) of around 19,000 tons (IOTC-WPNT11 2021).…”

Potential Fishing Zones Estimation Based on Approach of Area Matching Between Thermal Front and Mesotrophic Area

“…Research on Potential Fishing Zones (PFZ) is still growing, where many parameters have been used. As the well respond of fishes with changes in temperature and congregate around the upwelling makes potential fishing zones using thermal front have been developed in Indonesian water with 0.5 o C as a gradient threshold Harsanugraha et al, 2014;Jatisworo & Murdimanto, 2013;Jishad et al, 2019), water fertility can be seen from the distribution of chlorophyll-a concentration also used as parameters to predict potential fishing zones with 80% success effectiveness where the peak harvest of tuna usually appears when chlorophyll-a levels are high (Nurdin et al, 2017;Syah et al, 2020;and Zainuddin et al, 2006). The chlorophyll in high concentrations mostly associated with cool waters and its elevated structures are associated with ocean thermal front (Wijesekera et al, 2016).…”