Determination of potential fishing ground of mackerel fish (Rastrelliger kanagurta) using satellite imagery in the Malacca Strait

Mackerel fish (Rastrelliger kanagurta) is a fishery commodity in high demand by the community which is caught in the Malacca Strait. The number of mackerel catches tends to fluctuate every month because it is influenced by different mackerel fishing grounds. Determination of fishing ground tends to use traditional methods such as seeing ripples and a flock of birds flying above the water surface. This study aims to determine the effect of sea surface temperature and chlorophyll-a concentration on mackerel catches and determine the value of primary productivity of the VGPM model every month and also to determine the potential fishing ground to catch mackerel fish based on the sea surface temperature (SST) and chlorophyll-a concentration and Aqua MODIS satellite image data (SST and Chlorophyll-a) were downloaded from oceancolour.gfc.nasa.gov while the catch data were obtained from the Belawan Ocean Fishery Port, the data was taken from 2016 to 2020. The influence of SST and Chlorophyll-a concentration was analyzed and visualized on a map. It was found that every month the potential fishing ground for catching mackerel fish has a different location due to the influence of sea surface temperature and fluctuating chlorophyll-a caused by seasonal changes that occur in Indonesia, where the average SST ranged from 30.01 to 31.34°C and the concentration of chlorophyll-a ranged from 1.48 – 2.28 mg/m3 from 2016 – 2020 with a high net primary productivity ranged from 802.12 – 1.341.59 mgC/m2/day from 2016 to 2020. The potential area for catching mackerel (Rastrelliger kanagurta) caught using purse seines in the Malacca Strait is in the coordinates range of 980 10"51.6” – 1000 19"4.8” (longitude) and 30 28" 48” – 4 0 56"34.8” (latitude) and perpendicular horizontally to the Langkat Regency to Asahan Regency shoreline with a distance under 12 miles to 50 miles. Information on potential areas for catching mackerel can help fishermen in fishing activities so that they are more efficient and catch maximum results.