Climate change is affecting corals everywhere – including in the Mediterranean, according to a new study.
Coral populations in the Mediterranean are suffering enormous damage from heat waves caused by climate change. Two iconic species, the red gorgonian (Paramuricea clavata) and red coral (Coralium rubrum), has lost between 80 and 90% of its total biomass since 2003, according to a new study.
The findings are very interesting. Coral populations are the mainstay of the marine ecosystem to which they belong, providing food and shelter for countless other species. The startling decline seen in this paper may be indicative of broader coral communities in the Mediterranean. If so, marine wildlife could be in a much more dire state than people think.
A sea of trouble
Daniel Gómez, a researcher at the Barcelona Institute of Marine Sciences, said: “We observed an average biomass loss related to initial biomass of 80% in the red gorgonian population and up to 93% for the red coral population studied,” ICM-CSIC) and lead author of the study.
Joaquim notes: “These data raise concern for the conservation of these iconic species, and they indicate that the impacts of the climate crisis are rapidly increasing with clear consequences for the landscape. submarines, where loss of coral is equivalent to loss of trees in the forest. Garrabou, is also a member of ICM-CSIC.
The authors explain that populations of the two coral species studied may not be able to recover under current conditions. Their plight is due to rising temperatures, but in particular significant heat waves that have impacted the region several times, with the first occurring in 2003.
The water temperatures are reaching a level that is completely intolerable for these corals, and maintaining that temperature for days, even weeks at a time, the authors explain. like. While Corals worldwide are affected, this is the first study to quantify the impact of climate change and heatwaves on Mediterranean corals in particular. Here, as elsewhere, climate change is causing mass fish deaths in coastal ecosystems.
Both species are symbols of the Mediterranean, underpinning the region’s complex ecosystems. They also play a large role in shaping the landscape and distinctive appearance of the sea.
The researchers now have information on the short-term response of corals to marine heatwaves. That said, corals are long-lived organisms with very slow population dynamics – they are slow to grow and produce new generations) – so understanding exactly how they respond to climate change logistics decades of research. And that’s what the team did.
They used data from a long-term project by the research group MedRecover, which tracks different coral populations in the protected marine area of Scandola (in Corsega, France), where mass fish deaths occur. after the 2003 heatwave. Of particular interest are population density, size structure, and total biomass, which are used as proxies to estimate the overall health of these coral communities. Data were collected for fifteen years after the heatwave (as of 2018).
The data show that all populations tracked in the study did not recover from the heatwave. In fact, they tend to fall apart. Today, they are functionally extinct, the team explains.
“We believe that one of the main reasons we are observing these collapse trajectories is the possibility of frequent exposure to heat waves. [in 2009, 2016, 2017, 2018]Cristina Linares, professor in the Department of Evolutionary Biology, Ecology and Environmental Sciences in the Department of Biology and a member of IRBio, co-author of the paper, said.
“During these heatwaves, temperature conditions in the study area reach extreme levels that are not suitable for these corals to live, which could cause new deaths for these corals. can perish and make recovery impossible.”
These populations are in serious danger of extinction, especially since the number and intensity of heat waves at sea are predicted to increase in the future as the climate crisis deepens. sharp. However, the team adds that there are likely to be some areas in the Mediterranean where the impact of climate change may be lower due to local factors. They concluded that they would act as ‘climate shelters’ to help preserve corals.
The study group “Population collapse of habitat-forming species in the Mediterranean: a longitudinal study of gorgonian populations affected by recurrent marine heatwaves” was published in the magazine Proceedings of the Royal Society B: Biological Sciences.
https://www.zmescience.com/science/mediterranean-coral-climate-change-83473753/ Corals in the Mediterranean are becoming ‘functionally extinct’ due to climate change