Cold-water corals, and the species Lophelia pertusa in particular, are the architects of complex reef structures.
Cold-water corals, and the species Lophelia pertusa in particular, are the architects of complex reef structures. They build the foundations of important habitats for deep-sea organisms that find protection as well as food within the structures. Coral reefs, however, react very sensitively to changing conditions. These include warming of the ocean waters, acidification, declining oxygen content, and the variable supply of food. A change in any one of these parameters, as a consequence of global climate change, for example, can impact the health of the total coral reef. According to the new study, therefore, it is important to understand exactly how these ecosystems react to environmental changes in order to be better able to protect them more effectively in the future.
First author Rodrigo da Costa Portilho-Ramos of MARUM – Center for Marine Environmental Sciences of the University of Bremen, with his colleagues, examined sediments from six cold-water coral locations in the North Atlantic and the Mediterranean in order to identify of the critical parameters that could trigger the mortality and ensuing proliferation of cold-water corals. Information providing insights to the environmental conditions of the past are stored in these sediments. This fact allows researchers to determine when and why cold-water corals flourished or not. The authors point out that the results could also be used to show how corals might respond to future climatic changes. The study analyzes the changes of the most important environmental factors over the past 20,000 years, the period of general global warming since the last glaciation, and compares them with the occurrence of the cold-water corals.
Image: Large colony of the cold-water coral Lophelia pertusa colonized by crinoids and soft corals in 700 meters of water (Porcupine Seabight, Irish continental margin). (Credit: MARUM – Center for Marine Environmental Sciences, University of Bremen)