A new research done by scientists from the Carnegie Institution for Science shows that seagrass meadows could help significantly reduce ocean acidification in the areas where it grows, if not for the entire ocean. The study, led by David Koweek and including the contributions of Ken Caldeira, was published recently in the journal Ecological Applications.
Since carbon dioxide in the air is often absorbed into the oceans and the carbonic acid that is eventually produced does no good to marine life, it is corrosive to organisms like mussels ad oysters and can disintegrate their shells which are made up of calcium carbonate.
It is seagrass that comes to the rescue of these organisms- it is not only a vital source of food for marine organisms but also helps prevent erosion of the sediments that are formed on the sea bed. It also filters bacterial pathogens from the sea water. They utilize carbon dioxide for their daytime photosynthetic activity.
Previous studies have suggested that estuaries and bays of California’s coastline are severely affected by ocean acidification. Therefore the research team took upon the task to see if seagrass meadows could change the pH of the ocean water around them. For the study, they worked with the data collected from seagrass meadows in Tomales Bay, which is an inlet of the Pacific Ocean in Marin County, California.
“Local stakeholders, such as California’s shellfish industry, want to know whether seagrass meadows may help to counteract ocean acidification,” explained Koweek. “Our results suggest that seagrass meadows along the California coast will likely offer the only limited ability to counteract ocean acidification over long periods of time.”
The computer simulations that were predicted showed that seagrass meadows could actually turn back years of the acidification but only by decades, which when put into contrast with almost 150 years of ocean acidification- looks quite unpromising. However, some models also suggest that the effect of seagrass could be much greater than this, especially the daytime period when photosynthesis occurs.
“We are starting to understand that some marine organisms, such as blue mussels, are actually able to shift the time of day in which they do most of their calcification. If other organisms are able to do the same, then even brief windows of significant ocean acidification buffering by seagrass meadows may bring substantial benefits to the organisms that live in them”, added Koweek.