Climate change impacts on living marine resources in the Eastern Tropical Pacific

Aim Project shifts in the habitat suitability of 505 fish and invertebrate species in the Eastern Tropical Pacific that are likely to occur by the mid-21st century under "high greenhouse gas emissions" (RCP 8.5) and "strong mitigation" (RCP 2.6) scenarios. Location The Eastern Tropical Pacific Ocean, a discrete biogeographic region from the Gulf of California to northern Peru. Methods Ensemble simulations of climate change effects on fish and invertebrate species caught by four major fisheries in the region, based on four species distribution models and three Earth system models. Results Simulation results indicated that species' habitat suitability increased or remained the same in the northern and southern margins of the Eastern Tropical Pacific but decreased by up to 14% in some fisheries along Central America. The largest declines in the average species habitat suitability index were projected for small pelagic fisheries (up to -46%), while the highest local species turnover was projected for coastal small-scale fisheries (up to 80%). Under RCP 8.5, species in the southern half and northern equatorial region of the Eastern Tropical Pacific were projected to shift south-east at a rate of approximately 30-60 km decade(-1), respectively. Demersal species were projected to move into shallower, inshore waters with a shift in depth centroids estimated at a rate of around 1 to 13 m decade(-)(1). Range shifts towards the equator reflect movements to cooler habitats that are characteristic of equatorial upwelling systems. Range shifts towards shallower, inshore waters reflect habitat compression associated with the expansion of oxygen minimum zones. Main conclusions Our findings highlight the importance of local-scale oceanographic and biological data to elucidate the multidimensional biogeographic shifts of key species, their potential impacts on fisheries in the region and the need to consider such shifts in the design of effective conservation and marine resource management measures.