Greenwire: One proposed geoengineering fix to help mitigate carbon dioxide in the atmosphere — dumping iron in the oceans to increase their CO2 absorption — could potentially increase the production of a neurotoxin, researchers say.
It has long been theorized that fertilizing the ocean with iron would lead to the growth of algae, which would in turn absorb CO2. However, one algae likely to be stimulated by the iron would be of the genus Pseudonitzschia, which produces a toxin — domoic acid — poisonous to shellfish and mammals like sea lions.
The study, conducted at a research platform anchored in the northeast Pacific and published in Proceedings of the National Academy of Sciences, shows the need to consider all the environmental implications of CO2 fixes, said William Cochlan from San Francisco State University, an author of the study.
“We saw some literature going around with claims like ‘there is no indication of toxicity to sea life’ — well, if you don’t measure it, of course there’s no indication, and we have to keep that kind of legalese out of science,” he said.
“If the end goal is to use it to fight climate warming, then we have to understand the consequences for marine life,” he added.
At least one firm exploring the use of iron fertilization, Climos, agreed that more research needs to be done on marine life impacts, according to a company spokesman.
“Moving forward, we need to understand exactly how deep-ocean phytoplankton respond to iron, be it naturally or artificially supplied; whether and in what situations domoic acid is produced, and how the ecosystem is or is not already adapted to this,” he said (Richard Black, BBC News, March 16). – PV