Predictions of Pacific Top Predator Diversity Using Global Climate Change Models

As top predators in marine systems are globally in decline due to overfishing and other anthropogenic threats, it is import to assess species at risk and habitats that are most important for conservation. Climate change scenarios have predicted an average rise from 1-6° C by 2100 which will effect the habitat and distribution of many marine species. The Tagging of Pacific Predators (TOPP) project has tagged 4300 animals resulting in 268,000 data-days. We used spatially explicit habitat models (e.g. generalized additive mixed models) to examine present-day distributions and foraging habitat of 23 top predator species in the Pacific from 2001-2010 as a function of fixed bathymetric variables, sea surface temperature, wind, Ekman pumping, mixed-layer depth, and chlorophyll-a. Consequently we used high-resolution climate models from the Geophysical Fluid Dynamics Laboratory to predict changes in habitat under A2 climate change scenarios. We found spatial changes in biodiversity patterns of top predators, particularly in the transition zone, highlighting changes in important conservation corridors. Some species were predicted to gain core habitat (e.g. two Albatross species) and some species were predicted to lose core habitat (e.g. two shark species). Understanding potential changes in biodiversity and habitat in the north Pacific is important to prioritize ecosystem based management strategies for the future.