March 16, 2010
Iron Fertilization Could Harm Aquatic Life
Adding iron to ocean water, believed to be an effective way to absorb carbon dioxide and fight global climate change, could actually be poisoning marine life, claims a new study released Monday.
Researchers from the University of Western Ontario, analyzed water samples obtained from open-ocean tracts in the northern Pacific Ocean. They found that the iron stimulated the growth of Pseudo-nitzschia, a type of algae which releases a toxic substance called domoic acid -- a neurotoxin that can harm or even kill various forms of birds and mammals.Domoic acid levels in the sample water were twice those found in the control group, according to the results of the study, which were published in the Proceedings of the National Academy of Sciences. The elevated levels of the toxin, which is also responsible for amnesiac shellfish poisoning in humans, raises "serious concern" about the practice of iron fertilization, the researchers claim.
According to a March 15 article by AFP reporter Karin Zeitvogel, "Scientists in the 1990s began fortifying small areas of the ocean where the sea water is rich in nutrients but low in plankton, to see if adding iron to the water would stimulate the growth of phytoplankton and boost carbon capture."
The practice is said to still be in its experimental phase.
Scott Doney, a senior scientist at Woods Hole Oceanographic Institution in Massachusetts, told Zeitvogel that any form of geo-engineering, such as iron fertilization, "may have unintended consequences."
"You have to weigh how the changes affect higher animals, how it affects fish and mammals," he added. "You have to know what are the trade-offs between how much carbon you actually store and how big an effect you have on the environment."
On the Net:
- University of Western Ontario
- Proceedings of the National Academy of Sciences
- Woods Hole Oceanographic Institution