Underwatertimes.com News Service - February 22, 2011 18:08 EST

The University of Rhode Island is helping to create an international oceanographic consortium to study the potential affects of fertilizing the oceans with iron in an effort to reduce the amount of carbon dioxide in the atmosphere and mitigate the effects of global warming.

Lewis Rothstein, URI professor of oceanography, said, "A great deal remains to be learned about ocean iron fertilization and how effective it could be in storing carbon dioxide in the oceans, and the formation of this consortium is an important first step."

Twelve member institutions of the In Situ Iron Studies (ISIS) consortium have signed a memorandum of understanding agreeing to support iron fertilization experiments in the open ocean in order to answer the many unknowns about the role of iron in regulating the ocean's capacity to remove atmospheric carbon dioxide. Members will follow internationally agreed practices regulating ocean iron fertilization research being developed under the London Convention/London Protocol.

Through the process of photosynthesis, tiny marine plants called phytoplankton use the energy of sunlight to convert carbon dioxide drawn down from the atmosphere into organic compounds they need to grow. When they die, a small fraction of the organic carbon sinks to the seafloor where it can remain locked away for decades or centuries.

According to Rothstein, phytoplankton need iron to grow, but large tracts of the sunlit surface ocean are iron deficient, which limits phytoplankton growth. Previous studies have demonstrated that iron fertilization can stimulate phytoplankton growth, but these studies have been limited in scope and in measuring sequestered carbon dioxide, so additional studies are needed.

Iron fertilization of the ocean involves the intentional addition of iron " usually chemical-grade iron sulfate " to an area of the sea to promote the growth of plankton.

The ISIS consortium is calling for additional research to be conducted into geo-engineering techniques such as iron fertilization to reduce the threats from climate change, but it also believes that these techniques should not be implemented before their efficacy and potential impacts are better understood. And if ever deployed, consortium members agree that they must be part of a comprehensive and aggressive global effort to limit and eventually eliminate carbon emissions.

"This is not a call for climate engineering; on the contrary this is a research consortium. It is premature to advocate for large-scale ocean iron fertilization, but it is time to conduct a focused research experiment that will examine the concept as comprehensively as we can," said Rothstein. "We want to make sure that it doesn't generate harmful side effects that might negatively affect the marine ecosystem."

The idea of ocean fertilization is a controversial one. Some detractors cite the risk of unintended environmental impacts, and the objective of the ISIS consortium is to provide insight into these concerns. Other opponents say ocean fertilization could distract from efforts to reduce carbon emissions into the atmosphere.

In addition to URI, the ISIS consortium members are the Antarctic Climate and Ecosystems Cooperative Research Centre, Australia; the National Oceanography Centre, United Kingdom; Moss Landing Marine Laboratories, California; Netherlands Institute for Sea Research; University of Hawaii; University of Illinois at Urbana-Champaign; University of Maine; University of Massachusetts Boston; University of Plymouth, United Kingdom; Woods Hole Oceanographic Institution; and Xiamen University, China.