Coral bleaching, acidification and prevention

OUR sea floor is a habitat and is rich in species that produce calcium carbonate shells or skeletons called marine calcifiers. Sea urchins, sea stars, coralline algae, crustaceans and numerous mollusks, such as mussels, find their home here.

According to experts, marine calcifiers play an important role in global biogeochemical cycles and serve important ecosystem functions. They are a food supply for other organisms and store carbon. At present, experts say, the ocean takes up a quarter of the CO2 released to the atmosphere by human industrial activities which have increased over the years with long-lasting consequences for the chemical composition of seawater and marine habitats.

Experts say that the two major threats to the health of our islands and Earth’s oceans are coral bleaching and ocean acidification.

Environmental stresses such as an increase in sea temperature force coral polyps to eject algae. As a result corals lose their color and their source of food and energy.

Additionally, bleaching can be particularly severe when there is a strong El Niño event, which can lead to an even greater increase in sea temperatures.

Dr. Yimnang Golbuu was recently awarded a prestigious PEW Fellowship Award in marine conservation. He has researched on coral bleaching and its potential to destroy resources that have been providing Palauans with food and resources for over 3,000 years.

The Nature Conservancy, the Palau International Coral Reef Center and a network of conservation professionals have been monitoring Palau’s reefs since 1998.

Ocean acidification, caused by greenhouse gas emissions, is another major threat to the state of the world’s oceans, experts say.

“Many human activities release carbon dioxide into the atmosphere. Oceans absorb some of this gas and when it dissolves in water it forms a mild acid, which makes a small but significant change to the overall acidity of the sea water. Sea water is normally slightly alkaline and the increase in carbon dioxide is making it less alkaline, but for the sake of convenience this is referred to as acidification. As the oceans become more acidic (less alkaline) there is less calcium carbonate available in the water and when this happens, the calcium carbonate in marine organisms can dissolve.”

According to the National Oceanography Center, a new study offers clues to the potential impact of ocean acidification on deep-sea, shell-forming organisms. Increasing atmospheric carbon dioxide is also increasing oceanic CO2. “Ocean acidification is therefore one of the most important research areas regarding the effects of elevated CO2 on deep-sea marine calcifiers and the marine ecosystem in general.”

A study found that almost a quarter of the deep sea, shell-forming species analyzed already live in seawater chemically unfavorable to the maintenance of their calcareous skeletons and shells.

The lead author of the study, Dr. Mario Lebrato of Christian Albrechts University in Germany, said: “The result surprised us. For us, it is a sign that many marine organisms actually can live and maintain their calcareous shells under chemically unfavorable conditions which may reflect their physiological and evolutionary history.”

For Micronesians, efforts to reduce greenhouse emissions will bring benefits to land and sea.

There is now a system in place that uses satellites and monitoring equipment that alert ocean managers so they can act to reduce other stresses on reefs.

Christy Sakaziro, Marianas Variety, 20 October 2016. Article.


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