Impacts of climate variability on the tuna economy of Seychelles

Many small island states have developed economies that are strongly dependent on tuna fisheries. Consequently, they are vulnerable to the socio-economic effects of climate change and variability, processes that are known to impact upon tuna fisheries distribution and productivity. The aim of this study was to assess the impacts of climate oscillations on the tuna-dependent economy of Seychelles. Using a multiplier approach, the direct, indirect and induced economic effects of the tuna industry declined by 58%, 34% and 60%, respectively, in 1998, the year of a strong warming event in the western Indian Ocean. Patterns in tuna purse seine vessel expenditures in port were substantially modified by strong climate oscillations. A cointegration time-series model predicted that a 40% decline in tuna landings and transhipment in Port Victoria, a value commensurate with that observed in 1998, would result in a 34% loss for the local economy. Of several indices tested, the Indian Oscillation Index was the best at predicting the probability of entering a regime of low landings and transhipment. In 2007, a moderate climate anomaly was compounded by prior overfishing to produce a stronger that expected impact on the fishery and economy of Seychelles. The effects of fishing and climate variability on tuna stocks are complex and pose significant challenges for fisheries management and the economic development of countries in the Indian Ocean.