Iron-Thirsty Algae Thwart Counter-Global Warming Plans
Blooms of red algae, which typically occur in coastal waters, are associated with the poisoning of ocean water and the destruction of coastal ecosystems. A new study finds that blooms of this deadly organism can also flourish out in the open ocean and can wreak havoc if the ocean’s iron levels increase.
This finding, reported in the Proceedings of the National Academy of Sciences, is relevant to scientists because it poses a severe ecological side effect to proposed plans to combat global warming. The authors of the paper, which include several UC Santa Cruz professors, warn that fertilizing the ocean with iron to combat the pressures of global warming, could irrevocably damage the ecosystems of the world’s oceans and disrupt the global food chain.
The microcosms that flourish in high-iron environments are diatoms belonging to the genus Pseudo-nitschia. When these organisms reproduce rapidly and create a bloom, significant amounts of a neurotoxin they release, domoic acid enters the food chain and poisons fish, birds, and aquatic mammals.
The discovery that Pseudo-nitschia thrive in iron-rich waters poses a significant setback to talks in the scientific community about potentially fertilizing ocean waters with iron to promote the growth of other algae that absorb carbon dioxide. However, as coauthor of the report and director of Moss Landing Marine Laboratories Kenneth Cole commented in the UCSC press release for the findings, “this work definitely reveals a wrinkle in those plans” because of the algae’s potential to destroy the ocean’s ecosystems and subsequently diminish the terrestrial food chain.
Mary Silver, the lead author of the study and professor of ocean sciences at UCSC, conducted research on the algae throughout the Pacific Ocean and adds, “to do iron enrichment on a large scale could be dangerous because, if it causes blooms of Pseudo-nitschia, the toxin might get into the food chain, as it does in the coastal zone.”
Though he thinks nitrogen fertilization of the oceans would be dangerous and unwise, Cole believes that all people, scientists and citizens alike should continue to combat global warming. “In light of these findings, we should redouble our efforts to reduce carbon emissions, the primary culprit for ocean ecosystem damage worldwide,” he said.