Effects of mercury on endocrine physiology of a caiman

Mercury is a harmful environmental contaminant that can be found all around the world. It is naturally present but human activities, such as gold mining and fossil fuel combustion, increase its levels. The Amazon region is particularly affected due to high natural level of mercury in the soil, which have additionally been elevated by goldmining activities for decades. Mercury is especially dangerous because it builts up within animals and then biomagnifies through the entire food chain, making top predator such as crocodiles particularly vulnerable to mercury contamination. Mercury is extremely toxic and can harm an animal`s reproductive system, behavior, and cognitive abilities. Even though crocodiles may seem tough, environmental toxins such as mercury can have negative effects on them. However, knowledge on mercury toxicity in reptiles is limited. This project investigates how mercury contamination affects the reproductive behavior and hormone physiology of a south-American crocodile species, the smooth-fronted caiman. To do so, we will study how caimans respond to stress, and evaluate if mercury contamination affects this stress response. We will also study if mercury influences caiman reproduction and parental care, and how it affects the hormones of baby caimans. Results of this project will allow us to better understand the impact of mercury contamination on physiology and reproduction of caimans. This will be useful to interpret environmental contaminants and aspects related to conservation issues of top predators, and crocodiles in particular.