Identification of productive miter squid fishing grounds using a generalized additive model in Indonesian Fisheries Management Area 711

This study aimed to evaluate the factors affecting the catch rate and predict the potential catch for the determination of productive fishing grounds for miter squid (Uroteuthis chinensis) in the Indonesian Fisheries Management Area 711 for 2020. A vessel monitoring system and landing data from 66 cast nets were used to investigate catch per unit effort. Depth, chlorophyll-a, and sea surface temperature from satellite imagery combined with the month and geographic location of fishing were evaluated for their effect on catch per unit effort using a general additive model. The best model output was employed to identify productive fishing grounds. The results revealed that the average monthly catch rate ranged from 89.43- 337.47kg h^-1, with the highest occurring in May. Three significant variables affected the catch rate: month, latitude, and sea surface temperature, with contributions of 42.6%, 33.6%, and 12.7%, respectively. The catch rate continued to rise from March to May and tended to increase at higher latitudes where sea surface temperatures ranged from 27.6- 29.5°C or 31.5- 32.2°C. Based on the monthly map of predicted potential catch, the most productive fishing grounds were located in the waters between the islands of Anambas, Natuna, and Tambelan.  These findings can support marine spatial planning and squid resource management in IFMA 711.