Study: Rising Greenhouse Gases Profoundly Impact Microscopic Marine Life; 'We're Engaged In A Global

MERCED, California -- The prolonged, extensive emission of greenhouse gases over the next several decades could have significant impacts on ocean life, according to a study by UC Merced marine biologist Michael Beman.

Because nitrogen is an important nutrient for all organisms, this could ultimately have significant impacts for all forms of marine life.

"There is growing concern about this issue because human activities are modifying ocean pH so rapidly," Beman said. "While we do not know what the full effects of changing the nitrogen cycle will be, we performed experiments all over the world and believe that these changes will be global in extent."

In every instance, when the pH was decreased, the production of the oxidized forms of nitrogen used by phytoplankton and other microorganisms also decreased. That nitrogen is produced through the oxidation of ammonia in seawater by microscopic organisms.

Such a reduction could lead to a substantial shift in the chemical form of nitrogen supplied to phytoplankton, the single-celled aquatic "plants" that form the base of the ocean's food web. The decrease in nitrogen would likely favor smaller species of phytoplankton over larger ones, possibly creating a domino effect throughout the food web.

This is an important step in furthering science's understanding of how continued increases in greenhouse gas emissions will affect marine life on a global scale and another example of UC Merced researchers addressing society's most challenging problems.

"Nevertheless, our results can be used to estimate the potential impacts of acidification on the marine nitrogen cycle and on marine life in general. These effects could be substantial and deserve additional study."