Sperm whale faeces ‘offset CO2 emissions’
Sperm whale faeces may help oceans absorb carbon dioxide from the air, scientists say.
Australian researchers calculate that Southern Ocean sperm whales release about 50 tonnes of iron every year.
This stimulates the growth of tiny marine plants - phytoplankton - which absorb CO2 during photosynthesis.
The process results in the absorption of about 40,000 tonnes of carbon - more than twice as much as the whales release by breathing, the study says.
The researchers note in the Royal Society journal Proceedings B that the process also provides more food for the whales, estimated to number about 12,000.
Phytoplankton are the basis of the marine food web in this part of the world, and the growth of these tiny plants is limited by the amount of nutrients available, including iron.