Penguins of Antarctic poison with feces

The waste of penguins has never been considered a threat to the environment. But, according to a recent study, it is the main cause of arsenic accumulation in Antarctica.

A team of experts at China's National University of Science and Technology conducted measurements of arsenic in the faeces of three species of birds and two species of seals living on Ardley Island in Antarctica.

The results show that Gentoo penguins contain more arsenic than all the Antarctic animals - almost twice as much as the seagulls and three times the seals.

The research team measured arsenic rates in sediment samples from an island without penguins in Antarctica but geologically similar to Ardley Island. The results show that the arsenic ratio is only half that of Ardley Island. They decided to explore the correlation between the number of penguins and the arsenic ratio in the soil.

Gentoo penguin.Photo: coolantartic.com.

A study in 2000 demonstrated that penguin's droppings alter the geochemical composition of the lake bottom sediments. Scientists took mud from the bottom of a lake on Ardley Island to find out how arsenic changes in the past 1,800 years, while estimating the change in the number of penguins.

They found that changes in the number of penguins always led to a proportional change in arsenic levels at the bottom of the lake.

Arsenic is an environmental pollutant in water. It is absorbed by the mollusks and spreads in the food chain and enters the body of predators like penguins.

Experts have yet to explain why penguins' feces contain more arsenic than other Antarctic fauna, such as seals.