About This Project

The highest amphibian biodiversity across the globe is found in Madre de Dios, Peru, but this biodiversity may be threatened by mercury pollution from artisanal and small-scale gold mining (ASGM). Mercury is a neurotoxin and high levels have been reported in fish and raptors in this region. I created a vulnerability map for amphibians using remotely sensed imagery. This work will test map accuracy by quantifying mercury levels in soil.

Ask the Scientists

What is the context of this research?

Madre de Dios, Peru has the highest biodiversity of reptiles and amphibians and is home to many other animals such as giant river otters, harpy eagles, and jaguars.

This biodiversity is threatened by resource extraction. Gold mining is common and occurs along national parks and in the Amazon rainforest. Mercury (Hg) used in the mining process enters the environment when burned and through tailings. Hg persists in the environment for decades. When methylated by aquatic organisms, it has serious neurotoxic effects.

We know that Hg pollution is a problem; elevated levels of Hg have previously been reported in fish and raptors. Amphibians may be particularly at risk due to their dependence on water during the larval stage and their current global decline.

What is the significance of this project?

ASGM deforestation in this region is well-studied, but we do not know the spatial impact of Hg pollution on wildlife. We know Hg negatively affects amphibian speed and response time, size, and mortality and is worthy of study. I use remotely sensed data and multi criteria assessment to build on our knowledge of regional ASGM. This study is the first to create maps detailing vulnerability of amphibians and protected areas to Hg pollution. Such maps, if proved accurate, can be used to identify where formal protection should be evaluated or existing protection expanded. The effects of future ASGM activities can be minimized by choosing low vulnerability areas. Thus, there is high value for local managers.

What are the goals of the project?

I have created a vulnerability map that shows which areas in Madre de Dios should be most vulnerable to mercury pollution. This was done using entirely remotely sensed data, or data collected using satellites. Using remotely sensed data is beneficial because it is cost-effective, hard to visit areas can safely be studied, and a larger study area can be examined. To determine if the vulnerability map I have produced is accurate, I need to quantify mercury levels in the field and compare them to the vulnerability map created.

Thus, the goal of this final stage of the research is to use in-situ measurements of mercury levels in soil samples and compare them with the vulnerability map already created. This will allow us to determine map accuracy and make any refinements.