Projected climate change impact on immature albacore tuna habitats in the Indian Ocean by using sea surface temperature and chlorophyll data: Ensemble forecasting

Abstract

This study employed an arithmetic mean model with sea surface temperature and chlorophyll data (2-month lag) to determine the projected impact of climate change on the immature albacore tuna habitat in the Indian Ocean. Albacore tuna fishing data from Taiwanese longline fishery from 2000 to 2016 were used. Standardization of the nominal catch per unit effort data was performed to prevent bias and overestimation resulting from various temporal and spatial factors. In the Indian Ocean, potential immature albacore habitats exhibited significant habitat suitability index (HSI) changes in response to future climate change levels. As the water stratifies in a projected warm climate, low HSI areas were enlarged, and potential immature albacore habitats exhibited a net southward shift. Although the CMIP5 climate model sea surface temperature projections generated different HSI patterns for immature albacore, our results from the ensemble median immature albacore habitat forecasts provided information useful for assessing risks and adaptation strategy options for albacore fishery resources under climate change. The trends of the potential immature albacore habitat distribution could also be cautiously used to inform resource stakeholders’ decisions.