Ocean acidification affects important nutrients

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 20 December 2010

Increasing acidity in the sea’s waters may fundamentally change how nitrogen is cycled in them, say marine scientists who published their findings in this week’s issue of the journal Proceedings of the National Academy of Sciences (PNAS).

Ocean acidification will have widespread effects on marine ecosystems. Credit: iStockphoto/Dirk-Jan Mattaar

Nitrogen is one of the most important nutrients in the oceans. All organisms, from tiny microbes to blue whales, use nitrogen to make proteins and other important compounds.

Some microbes can also use different chemical forms of nitrogen as a source of energy.

One of these groups, the ammonia oxidizers, plays a pivotal role in determining which forms of nitrogen are present in the ocean. In turn, they affect the lives of many other marine organisms.

“Ocean acidification will have widespread effects on marine ecosystems, but most of those effects are still unknown,” says David Garrison, director of the National Science Foundation (NSF)’s Biological Oceanography Program, which funded the research along with NSF’s Chemical Oceanography Program.

“This report that ocean acidification decreases nitrification (the amount of nitrogen) is extremely important,” says Garrison, “because of the crucial role of the nitrogen cycle in biogeochemical processes-processes that take place throughout the oceans.”

Very little is known about how ocean acidification may affect critical microbial groups like the ammonia oxidizers, “key players in the ocean’s nitrogen cycle,” says Michael Beman of the University of Hawaii and lead author of the PNAS paper. Continue reading