Education Level

Undergraduate

Faculty Advisor(s)

Professor David Taylor

Academic Department(s)

Marine Biology

Comments

This research was presented at the 2024 Rhode Island Summer Undergraduate Research Symposium, held on Friday, July 26, at the University of Rhode Island and supported by independent research with Dr. David Taylor

Symposium Date

2024

Abstract

Fish provide essential nutrients and proteins beneficial to human health, yet may pose certain risks due to contaminants in edible tissues. For example, mercury (Hg) is a widespread toxicant that bioaccumulates in fish muscle (filet) tissue. Accordingly, federal and state government agencies issue consumption advisories to minimize diet related Hg exposure. Fish consumption advisories, however, often fail to account for small-scale spatial variations in Hg contamination, especially in freshwater fishes. This study examined site-specific Hg concentrations in bluegill sunfish (Lepomis macrochirus), pumpkinseed sunfish (L. gibbosus), largemouth bass (Micropterus salmoides), chain pickerel (Esox niger), and yellow perch (Perca flavescens), all of which are commonly consumed freshwater species. Target fish were collected from 57 lakes and ponds throughout Rhode Island from 2007 to 2023 using an electrofisher and rod & reel. Muscle tissue was extracted from each fish and measured for total Hg concentration (ppm wet weight) using automated atomic-absorption spectroscopy. For each waterbody, fish Hg data were size standardized, and mean values were analyzed relative to water chemistry and surrounding land use patterns. Total Hg concentrations were inversely related to pH and the areal extent of medium-highly developed lands. These results are attributed to increased rates of bacterial methylation of Hg in acidified waterbodies. Moreover, developed and disturbed watersheds often have a net decrease in terrestrial-to-aquatic Hg transport due to the loss of deciduous forests. Aquatic environments adjoining disturbed landscapes also receive excessive nutrient and organic inputs, which lead to biogeochemical conditions that inhibit Hg bioavailability to the food web.

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