Ecosystem Effects of Climate and Global Change in the Marine Ecosystem of the Northern Gulf of California, Mexico

Future changes in marine ecosystems due to climate and global change may have important socioeconomic consequences by altering the biomass and spatial distribution of target species. We explored the potential ecosystem effects of projected climate change effects on the marine ecosystem of the Northern Gulf of California, Mexico using an Atlantis Ecosystem Model. We tested nine scenarios simulating the combination of climate change effects: no effect, ocean warming corresponding to projected warming in 2020-2050 (RCP scenario 8.5), and ocean acidification (simulated as the general effects of lower pH on marine organisms), fishing (no fishing and baseline fishing conditions), and spatial management (the spatially-explicit restrictions of Marine Protected Areas in the region). We found that fishing determined system and species response to climate change. Generally, ocean warming and ocean acidification restructured the food web similarly through the combination of direct effects on species’ mortality and growth and indirect trophic effects. Primary producers, mid and upper trophic levels decreased, while some low-trophic level fish and invertebrates benefited from reduced predation. Our results suggest that both ocean warming and ocean acidification could restructure the food web and negatively affect the ecosystem services and biodiversity of the Northern Gulf of California.