Over millions of years of their evolution, corals have experienced and survived major environmental changes. Like tree rings, their skeletons are an environmental archive that allows researchers to gain insights into the past. From the smallest differences in the chemical composition of coral skeletons, conclusions can be drawn about former environmental conditions. However, many details on the control and regulation of skeletal formation processes of corals are still unknown.
To learn more about these processes, the researchers used a natural laboratory off the east coast of Mexico. There, groundwater seeps from almost circular holes in the seabed, so-called ojos. The water has previously dissolved calcium carbonate from the Yucatan peninsula rocks as well as high carbon dioxide from soil respiration. It is more acidic than normal seawater but contains more dissolved carbon and thus resembles the seawater of the distant future.
Conditions - Porites - Astreoides - Ojos - Corals
Despite these unfavorable conditions, the hard-coral Porites astreoides has settled at these ojos. However, the corals there grow more slowly than similar species outside the ojos. "Unlike corals that are exposed to such an acidic environment in laboratory experiments for only a few weeks to months, the corals we sampled live under such conditions for their whole life history," says Prof. Dr. Adina Paytan of the University of California Santa Cruz, co-author of the study..
For the study, samples were taken from corals living at different distances from the ojos. The researchers were thus able to study corals of the same species with varying degrees of change in seawater composition.
Research - Ratio - Boron - Carbon - Isotopes
It is known from earlier research that the ratio of boron and carbon isotopes in...
Wake Up To Breaking News!
What's more plentiful, hydrogen or stupidity?