Date of Award

Spring 5-25-2024

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Terri Maness

Abstract

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury accumulation in breeding birds. Only a limited number of studies have investigated wintering birds, and an even smaller percentage have examined the influence of sex on mercury accumulation. I used energy dispersive x-ray fluorescence to measure the mercury concentration in the liver and feathers of mallards (Anas platyrhynchos) wintering in Louisiana. Sex did not influence liver or feather mercury concentrations and there was no correlation between feather and liver mercury concentration within individuals. A noteworthy finding was that birds with higher hepatic mercury concentrations had smaller livers, particularly females, raising concerns about potential impacts on their health. The mercury levels detected in most of the birds were unlikely to pose much concern for hunters who consume them, but pregnant women and children may want to be mindful of how much duck meat they consume per week.

Download

Share

COinS