SYDNEY (Reuters) - Southern Ocean sperm whales offset their carbon footprint by defecating, scientists said on Wednesday, releasing tonnes of iron a year that stimulates the growth of phytoplankton which in turn absorb carbon dioxide.
Each whale releases about 50 tonnes of iron a year, their natural fertilization stimulating the process of photosynthesis.
An estimated 12,000 sperm whales that inhabit the Southern Ocean absorb about 400,000 tonnes of carbon each year, twice the amount they release by breathing, said scientists from Flinders University in South Australia.
