Assessing the effects of climate variability on the distribution of albacore tuna (Thunnus alalunga) in the southern Indian Ocean using Remote Sensing data

Variations in the abundance and distribution of albacore tuna populations have been associated with large-scale climatic factors in the Southern Indian Ocean. Spatial and temporal distribution patterns of albacore tuna were studied based on catch data of Taiwan longline fishery during the period 2009-2014. A geographic information system (GIS) was used to compile a fishery database to statistically explore the catch per unit effort (CPUE), distribution and relationship between the distribution and environmental factors. Environmental factors such as sea surface temperature (SST), chlorophyll-a (CHL-a), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD) and eddy kinetic energy (EKE) were taken to better understand the albacore tuna distribution. Results indicated that albacore tuna CPUE hotspot were mainly distributed between 30° E to 110° E and 25° S to 50° S. SST was the major factor affected the albacore tuna distribution in the Southern Indian Ocean. Lower temperature showed higher distribution of albacore tuna. These findings provide preliminary insights into the some of the key environmental features driving the distribution of albacore tuna in the Southern Indian Ocean and associated variability in fisheries catches.