Self-caught fish consumption and methylmercury advisories in Tuscaloosa County, Alabama

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
University of Alabama Libraries

Methylmercury is a naturally occurring toxin, capable of bioaccumulation within aquatic ecosystems. Diets high in fish with elevated levels of methylmercury can lead to neurological impairments, especially in young children. Low-income and minority anglers have been found to consume higher rates of self-caught fish than individuals from other demographic groups, and may incur a higher risk of methylmercury-related hazards. This study uses creel surveys and data from the Alabama Department of Environmental Management’s Fish Tissue Monitoring Program to identify trends in consumption, advisory awareness, and methylmercury concentration across two demographically representative sites in Tuscaloosa County, Alabama. Surveys suggest that anglers reporting lower household income reported higher rates of self-caught fish consumption. African American anglers reported consuming a significantly higher rate of self-caught fish than white anglers (mean calculated consumption = 67.17 g/day and 23.51 g/day; p = 0.004). Anglers indicating an awareness of consumption advisories reported consuming self-caught fish at a nominally lower rate than anglers who indicated being unaware of advisories. Fish tissue data indicates higher levels of methylmercury in largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus) near the Lake Tuscaloosa study site where current advisories are issued. Environmental conditions seem to support greater rates of mercury methylation and bioaccumulation at the site with existing advisories. Still, there is a perception amongst some anglers that fish from the Black Warrior River – where no advisories are issued – are more dangerous to eat than those in Lake Tuscaloosa. These reactions may call into question the quality and efficacy of the current advisory system. Misinformation surrounding methylmercury’s presence and health consequences suggest greater public understanding may increase the effectiveness of fish consumption advisories. While the study focused on consumption by adult anglers, future research may also seek to determine consumption trends in more vulnerable populations: children, pregnant and nursing women, and women who may become pregnant. This study contributes to a body of research that seeks site-specific data to create a more comprehensive understanding of risks related to fish consumption. It also exposes the gradations of advisory effectiveness, risk perception, and of threats to wellness anglers face beyond those toxins fish contain.

Electronic Thesis or Dissertation