Coral reefs in the Flower Garden Banks National Marine Sanctuary 100 miles off the Texas coast have remained healthier than many of their counterparts around the world in the face of climate change. But warming waters in the Gulf of Mexico could change that, warn scientists at Rice University, the University of Colorado Boulder and Louisiana State University in a recent paper in the Journal of Geophysical Research (JGR) Biosciences.
The researchers used models maintained by the National Center for Atmospheric Research to simulate climate warming from 2015 to 2100 under two scenarios. The first was “business as usual,” with very high emissions, and the second involved reduction of emissions to high levels. An analysis of regional warming patterns in each suggested the Gulf of Mexico could see critically warm temperatures as early as 2050. The key determinant of coral mortality in each scenario is the number of months corals are exposed to prolonged temperatures hotter than the hottest average months projected for 2015-2034.
One of the clear findings is that it matters which scenario prevails, according to Sylvia Dee, a climate modeling expert at Rice University and one of the authors, who spoke with Texas Climate News. The research indicates that curbing emissions during the next 10 to 20 years could make a big difference for these reefs.
Reef-building hard corals host photosynthetic algae that help feed the coral organisms. Corals also rely on carbonate minerals in seawater to construct their hard skeletons. Climate-change-related warming temperatures and increased acidification in the ocean threaten these processes. Prolonged, abnormally warm temperatures, for example, can cause corals to expel their algae, a phenomenon known as bleaching. If water temperatures drop, corals take back the algae and recover. If temperatures remain high enough, corals eventually starve.
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Melissa Gaskill, Texas Climate News, 23 November 2022. Full article.
