Predicting Winter Potential Fishing Zones of Albacore Tuna (Thunnus Alalunga) Using Maximum Entropy Models and Remotely Sensed Data in The South Indian Ocean

Abstract

Albacore tuna (Thunnus alalunga) is one of the important commercial species of the longline fishery in the South Indian Ocean (SIO). The satellite-based oceanographic data of sea-surface temperature (SST), sea surface chlorolyll-a (SSC), sea surface salinity (SSS), mixed layer depth (MLD), sea-surface height (SSH) and eddy kinetic energy (EKE), were used to evaluate the effects of oceanographic conditions on the potential fishing zones of Albacore tuna and to explore the spatial variability of these features in the SIO using the maximum entropy models (MaxEnt). The results revealed its potential for predicting the spatial distribution of Albacore tuna and highlight the use of multispectral satellite images for describing habitats. The winter higher nominal catch per unit effort (CPUE) (>3.9 inds./1000Hooks) of Albacore tuna was mainly distributed in the waters of 25 to 40°S, South Indian Ocean. The spatial habitat patterns were explained predominantly by SST (18-22°C) and indicated that SST is the most influential factor in the geographic distribution of Albacore tuna. Hotspot habitat formation were also possibly related to the Chl-a (0.09-0.12mg m−3) in wintertime.