this marine acidification As a result global warming endanger not only corals (authentic ecosystems in themselves), but also species such as: crustaceans, mollusks or sea urchins whose shells are affected by this phenomenon. Worst case, these organisms may not have time to adapt to this rapid acidification process of waters, according to recent research.
A new study led by the Institut de Ciències del Mar (ICM-CSIC), which also participated in the British Antarctic Survey, the Institute of Oceanology, the Polish Academy of Sciences and the University of Gdańsk (Poland), revealed that global warming is global. climate and ocean acidification they control marine organisms that build their skeletons and shells with calcium carbonatesuch as corals, bryozoans, mollusks, sea urchins and crustaceans.
The study recently published in the journal ultrasoundfocuses on organisms with calcium carbonate skeletons from around Antarctica in the Southern Ocean. The greater solubility of calcium carbonate in waters that are more acidic and contain more carbon dioxide (CO2), such as the coldest waters of the polar regions, makes it difficult for these creatures to form their skeletons.
Bryozoans, key to understanding impact
To prepare the study, the research team analyzed the skeleton of marine organisms called bryozoans.small filter-feeding invertebrates live on the seafloor and can provide basic complex habitats for many species.
“Like corals, bryozoans can live in colonies and form skeletons based on calcium carbonate, but they are more geographically distributed, particularly in Antarctic waters. They also have skeletons of a very diverse composition and are important carbonate producers in the southern hemisphere, which makes them excellent model organisms for studying the effects of global change”, disclosing Blanca Figuerola, ICM-CSIC researcher and main author of the study.
In this sense, the expert adds that the skeletons of bryozoans consist of two main types of calcium carbonate, calcite and aragonite. they may also contain magnesium, which can make skeletons more vulnerable to acidification.
“We identified a clear pattern of expanding on a global scale: at higher seawater temperatures, species with skeletons containing higher magnesium concentrations are more common,” says Huw Griffiths, a British Antarctic Survey researcher and co-author of the study.
According to Figuerola, “this means that many marine species with high levels of magnesium in their skeletons as seawater temperatures rise, the ocean will be more vulnerable to acidificationand given the observed and predicted rapid changes in the temperature and chemistry of our oceans, these organisms may not have time to adapt to these new conditions”.
The large scale of this work has been made possible by collaboration with members of the International Society of Bryozoology, which has allowed for increasing data on the mineralogy of bryozoan skeletons in a wide variety of species living from the poles to the poles. lower. tropics.
The future of marine limescalers
Increasing CO2 emissions are changing the oceans, causing an increase in temperature and changes in water chemistry. When the oceans absorb CO2, they become acidic., a phenomenon we know as “ocean acidification”. In turn, dissolved CO2 reacts with seawater to form carbonic acid, which reduces the carbonate concentration in seawater.
As a result, calcified organisms that use calcium and carbonate ions dissolved in seawater to build their shells and skeletons, reduced carbonate availability and increased acidity. For now, it is unknown to what extent calcified species are able to adjust their skeletal chemistry in response to the combination of these (temperature and pH) and other stress factors.
For future research, Figuerola, in collaboration with members of the MedRecover team and other researchers, will expand this work carried out within the MedCalRes project to examine possible morphological, metabolic and microbiome responses. calcifying organisms, including bryozoans and corals, in the face of ocean acidification and warming.
Reference work: https://onlinelibrary.wiley.com/doi/10.1111/ecog.06381
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