Belgian scientists have found that penguin poo is causing concentrations of pollutants to build up in the Antarctic.
Adrian Covaci from the University of Antwerp and colleagues collected samples from around the nesting sites of Antarctic non-migratory Adelie Penguins and found unexpectedly high levels of organic pollutants. These chemicals, which were at concentrations 10-100 times greater than anticipated, come from man-made sources including brominated flame retardants and organochlorine pesticides. They are normally carried in the air and by ocean currents, so why should they have reached such high levels around the penguin colonies? The answer many be bio-accumulation - the concentration of chemicals by the food chain.
The penguins are catching and eating fish, which pick up traces of the pollutants from the seawater. But by eating large numbers of fish the penguins increase their intake considerably. Back ashore, their guano and the carcasses of their dead, which accumulate around their nesting sites lead to a build up of the chemicals in the soil.
Commenting on the study, UK organic pollutant researcher Kevin Jones from the University of Lancaster says these results are important because they highlight an unusual mechanism that is moving chemicals around the planet. Particularly since the long term consequences of a build up like this are not known.