
Several small studies have shown that some fish in the Madre de Dios region in southeastern Peru contain dangerous levels of mercury. A larger study of mercury in fish and in people will soon get under way under the direction of Luis Fernández, a tropical ecologist from the Carnegie Institution for Science at Stanford University.
It's been one dam story after another in South America in the past week or so.
The 2,750 Mw HidroAysén dam in southern Chile got the green light from an appeals court after a three-month suspension to review objections from environmentalists.
The on-again-off-again Belo Monte dam in Brazil is off again, at least for the moment. A judge suspended construction because of the likely impact on fish stocks and local communities that depend on fisheries. The dam would also flood an area occupied by indigenous people.
How would you like a T. rex up the nose?
A new species of leech, called Tyrannobdella rex, which was found attached to the nasal mucous membrane of a 9-year-old girl in the central Peruvian region of Chanchamayo, made the International Institute for Species Explorations list of the top 10 new species described in 2010.
Read more: Tyrant leech and other new species make Top 10 list

Barbara Fraser is a freelance journalist based in Lima, Peru. With 20 years of experience in Latin America, she puts a human face on current events and public policy. She offers research, writing, editing and photography services, with particular expertise in Latin American, environmental, public health and social issues.