Potential Impact of Global Warming on Tropical Tuna Habitat

Recent studies suggest a reduction of primary production in the tropical oceans due to changes in oceanic circulation under global warming conditions caused by increasing atmospheric CO2 concentration. This might affect the productivity of higher trophic levels with potential consequences on marine resources such as tropical tuna. Here we combine the projections of up-to-date climate and ocean biogeochemical models with recent concepts of representation of fish habitat based on prey abundance and ambient temperature to gain some insight on the impact of climate change on skipjack tuna, the specie that dominates present day catches. For a 2xCO2 world, our results suggest significant large scale changes of skipjack in the equatorial Pacific. East of the date line, conditions are improved by either an extension or an eastward displacement of the present day favorable habitat zones of the western equatorial Pacific.