Penguin guano in the Antarctic is adding to organic pollutant problems there, say Belgian scientists.

Adrian Covaci at the University of Antwerp, Belgium, and colleagues found unexpectedly high levels of organic pollutants in the soil around a colony of non-migratory Adelie penguins in the Antarctic.  

Concerns about organic pollutant levels in the Antarctic have led to intensive studies into how they reach this remote region, said Covaci.  The pollutants originate from man-made sources such as organochlorine pesticides and brominated flame retardants, he explained. The routes through which they normally travel are air and ocean currents.  Recent studies have shown that migrating birds can also transport organic pollutants to the Antarctic in their body tissues, added Covaci.

 

Halogenated hydrocarbons can accumulate in the bird's bodies

   

Covaci's study shows that non-migratory penguins are also redistributing organic contaminants on a local scale, resulting in levels 10 to 100 fold higher than expected in the soil around their colonies.  

Covaci suggests that penguins are initially exposed to the contaminants by eating polluted fish, which have been contaminated through the food chain.  Bioaccumulation means that the penguins have high levels of contaminants in their bodies. The soil around the colony is then contaminated by penguin guano and carcasses.

Kevin Jones, an expert in organic pollutant transport at the University of Lancaster, UK, said the work is important. It highlights an unusual mechanism that is moving chemicals around our planet, said Jones.

Nina Athey-Pollard