Rising temperatures and ocean acidification due to anthropogenic climate change pose ominous threats to coral reef ecosystems in the Gulf of Mexico (GoM) and the western Caribbean Sea. Unfortunately, the once structurally complex coral reefs in the GoM and Caribbean have dramatically declined since the 1970s; relatively few coral reefs still exhibit a mean live coral cover of > 10%. Additional work is needed to characterize future climate stressors on corals reefs in the GoM and the Caribbean Sea. Here, we use climate model simulations spanning the period of 2015-2100 to partition and assess the individual impacts of climate stressors on corals in the GoM and the western Caribbean Sea. We use a top-down modeling framework to diagnose future projected changes in thermal stress and ocean acidification and discuss its implications for coral reef ecosystems. We find that ocean temperatures increase by 2-3°C over the 21st century, and surpass reported regional bleaching thresholds by mid-century. Whereas ocean acidification occurs, the rate and magnitude of temperature changes outpace and outweigh the impacts of changes in aragonite saturation state. A framework for quantifying and communicating future risks in the GoM and Caribbean using reef risk projection maps is discussed. Without substantial mitigation efforts, the combined impact of increasing ocean temperatures and acidification are likely to stress most existing corals in the GoM and the Caribbean, with widespread economic and ecological consequences.
Plain Language Summary
Coral reefs are among the most diverse and valuable ecosystems on Earth, and the coral reefs in the Gulf of Mexico (GoM) and the Caribbean Sea are no exception. In this region, coral reefs support vibrant recreation, tourism, and fishing industries. However, climate change, including rising temperatures and ocean acidification, threaten the future health of corals. To asses climate-change related risks to coral reefs in the Gulf of Mexico and the Caribbean Sea, this study uses climate model simulations spanning 2015-2100 to understand future changes in temperature and ocean acidification. Although many regions of the Gulf of Mexico and the western Caribbean Sea will cross the critical coral reef bleaching thresholds by mid-century, we hope that this work will inform and streamline mitigation efforts to protect vulnerable coral reef ecosystems and the valuable benefits and resources they provide to local communities.
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Key Points
- Sea-surface temperatures (SSTs) surpass critical coral bleaching thresholds by mid-century in the Gulf of Mexico (GoM) and Caribbean Sea
- The rate and magnitude of SST changes in the GoM/Caribbean more strongly influence future coral reef vulnerability than ocean acidification
- Future climate projections with high greenhouse gas forcing underscore the need for mitigation to ensure long-term coral reef preservation
Lawman A. E., Dee S. G., DeLong K. L. & Correa A. M., 2022. Rates of future climate change in the Gulf of Mexico and the Caribbean Sea: implications for coral reef ecosystems. Journal of Geophysical Research: Biogeosciences 127: e2022JG006999. doi: 10.1029/2022JG006999. Article.
