© AP Photo/Guam Variety News
A sperm whale calf swims next to its mother and a pod of sperm whales about four miles off the coast of the Agat Marina in Guam. New estimates suggest sperm whales' feeding habits help take in carbon.
Sperm whales in the Southern Ocean deserve credit for their fine work pumping iron for climate change, researchers say.
These whales have been falsely accused of breathing out enough carbon dioxide to contribute to the greenhouse gas build-up causing climate change, says Trish J. Lavery of Flinders University in Adelaide, Australia.
Of course the whales breathe, but earlier calculations overlooked the potential for whales to offset their emissions by introducing extra iron into the upper zone of water, Lavery said October 13 at the Biennial Conference on the Biology of Marine Mammals in Quebec City, Canada. The extra iron that whales bring up from their deep feeding encourages plankton growth. That growth traps carbon, much as human-run iron-enrichment experiments in the ocean might, Lavery and her colleagues contend.
According to the team's calculations, sperm whales in the Southern Ocean should rank as carbon neutral at least. The animals may even be capturing a net 5 million metric tons of carbon from the atmosphere per year, Lavery says.
