Detecting the feeding habitat zone of albacore tuna (Thunnus alalunga) in the southern Indian Ocean using multisatellite remote sensing data

Abstract

Remote sensing is an effective method for identifying potential feeding habitat zones. Spatial and temporal distribution patterns of albacore (ALB) tuna were studied using Taiwan longline fisheries data from 2009 to 2014. A generalized additive model (GAM) was used to compile a fishery database and statistically explore the relationship between distribution and environmental factors. Sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD), and eddy kinetic energy (EKE) were examined. The results indicated SST as the largest contributor on ALB distribution, followed by SSS and SSC. Catches per unit effort (CPUE) values indicated that ALB tuna were primarily distributed at 20°E–110°E and 25°S–40°S. The SST and SSS ranges for higher ALB abundance were 17–19 °C and 35.1-35.5 psu, respectively. SSC was positively related to CPUE as a result of ALB tuna habits in the current location during the study period (0.1–0.25 mg m-3). The predicted CPUE indicated that the potential feeding habitat zones were 35°S–40°S and 25°S–30°S during March and April–August, respectively. These findings provide preliminary insight into the key environmental features affecting the ALB distribution in the southern Indian Ocean.