Habitats at risk for ocean acidification

Due to the acidification of the oceans, marine fauna is in serious danger

by Lorenzo Ciotti
Habitats at risk for ocean acidification

Although many organisms suffer from increasing ocean acidification, some photosynthetic organisms benefit from it. One case is represented by diatoms; that is microscopic algae belonging to phytoplankton. For these organisms, the increase in CO2 in water increases their ability to carry out their own photosynthesis processes.

These processes can be carried out if in the presence of certain environmental conditions. Due to the acidification of the oceans, marine fauna is in serious danger. The lowering of the marine pH creates the phenomenon of coral bleaching; the calcium carbonate that makes up shells, molluscs, crustaceans and even coral, decreases in relation to the increase in acidity, thus losing the algae that live above the surface of the organism, leading it to death.

On Conservation physiology the study Biotic habitats as refugia under ocean acidification was published. The study researchers explain: "Habitat-forming organisms have an important role in ameliorating stressful conditions and may be of particular relevance under a changing climate.

Increasing CO2 emissions are driving a range of environmental changes, and one of the key concerns is the rapid acceleration of ocean acidification and associated reduction in pH. Such changes in seawater chemistry are anticipated to have direct negative effects on calcifying organisms, which could, in turn, have negative ecological, economic and human health impacts part of complex ecosystems.

Here, we use a qualitative narrative synthesis framework to explore how habitat-forming organisms can act to restrict environmental stress, both now and in the future; the ways their capacity to do so is modified by local context; and their potential to buffer the effects of future change through physiological processes and how this can be influenced by management adopted.

Specifically, we highlight examples that consider the ability of macroalgae and seagrasses to alter water carbonate chemistry, influence resident organisms under current conditions and their capacity to do so under future conditions, while also recognizing the potential role of other habitats such as adjacent mangroves and saltmarshes.

Importantly, we note that the outcome of interactions between these functional groups will be context dependent, influenced by the local abiotic and biotic characteristics. This dependence provides local managers with opportunities to create conditions that enhance the likelihood of successful amelioration.

Where individuals and populations are managed effectively, habitat formers could provide local refugia for resident organisms of ecological and economic importance under an acidifying ocean."