Caribbean fire corals survive global warming, disease and hurricanes

Caribbean fire corals have a unique survival mechanism that can endure even if the rest of the reef is destroyed by hurricanes, disease and global warming.

Fire corals can be a diver’s worst nightmare. An unintentional bump against a fire coral can be excruciatingly painful. However, they could also help preserve Caribbean reefs, which are threatened by hurricanes, disease, global warming and excess algae.

According to a long-term study, fire corals (Millepora) thrive there even as other corals die. This could help preserve some of the 3D environment that makes reefs excellent habitats for fish and other organisms.

Colleen Bove, a marine ecologist at Boston University, says that because they can withstand these stresses, fire corals are going to be crucial habitat providers. Bove was not part of the project.

Peter Edmunds began conducting annual surveys of marine life off St. John, one of the US Virgin Islands, thirty years ago. A 20-meter transect along a reef below the ocean was marked by a marine biologist from California State University, Northridge. He took photos of the vegetation that grew there each summer, including a 40-meter widened transect.

Edmunds has tracked how algae and different corals have withstood warming sea temperatures, hurricanes and other environmental stresses by examining the abundance of each organism in these “photo quadrats”.

Caroline Dubé, a marine biologist at Université Laval who studies the plasticity of Pacific fire coral, says Edmunds has accomplished something truly amazing. Since coral reefs experience so much disturbance, more needs to be done in this area.

fire corals

Although they look like typical hard corals, fire corals are closely related to jellyfish, which explains their painful sting. They can grow into “trees”, growing upwards with a stem and branches, or into leaves, spreading as a flat covering over rocks and other surfaces. Jeremy Jackson, an ocean biologist at the American Museum of Natural History and the Smithsonian Tropical Research Institute, first suggested more than 40 years ago that fire corals would have an advantage as Caribbean reefs were subject to hurricanes. and global warming. Now Edmunds thinks Jackson was right.

Globally, EdmundsLong-term data shows that many species of macroalgae, which are multicellular algae, have invaded Caribbean reefs. However, Edmunds today reports in Proceedings of the Royal Society B that fire corals quickly invade and encrust surfaces if hurricanes or other factors decimate macroalgae. To survive in confined spaces and provide an upright structure for other organisms to eat, live, or use in other ways, light coral shoots into its branching tree form when the reef becomes overcrowded.

Also read: The Great Barrier Reef experienced another mass bleaching event for the sixth time

Corals sometimes lose their green algae partners and die as a result of abnormally warm water, allowing macroalgae to repopulate the area. The branches of the tree form are also lost during hurricanes. However, Edmunds discovered that the fire coral quickly resurfaces somehow. As a result, the abundance of this coral may have been maintained and perhaps even increased slightly.

According to Edmunds, the stony coral friends of fire corals don’t do a great job of producing leaves and trees. Fire corals are therefore poised to take over shallow reefs in a world with frequent storms and fierce competition for bottom space.

Jackson expresses satisfaction that Edmunds’ extraordinary tenacity has allowed him to observe the ups and downs of fire coral dynamic. Unfortunately, Edmunds’ data also indicates that other corals are gradually becoming scarce. Due to coral bleaching and marine heat waves, millepora could take their place.

Bad news for the reefs

Nikolaos Schizas, a marine scientist at the University of Puerto Rico, Mayagüez, warns that because fire corals rarely form reefs several meters high and wide, they might not be able to save reefs. Schizas stressed the need to be reasonable about the extent of this potential.

Terry Hughes, a marine scientist from the Australian Research Council’s Center of Excellence for Coral Reef Studies, pointed out that although fire corals have been repeatedly destroyed by hurricanes and other disturbances, according to Edmunds data, fire corals will be get off better than most other corals.

Related article: Burial in the ocean: now you can turn into corals and help fight climate change after death

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Teresa H. Sadler