The Daily Bulletin Archive

Please join the Biology Department and the Great Lakes Center for the seminar “Through Their Eyes: What Fish Reveal about Mercury in a Hypoxic World,” presented by Roxanne Razavi, assistant professor of environmental biology at SUNY ESF, on Monday, November 6, at 3:00 p.m. in Science and Math Complex 151. Attendees are welcome to arrive at 2:30 p.m. to enjoy coffee and cookies before the seminar.

Abstract
Climate change–induced deoxygenation threatens aquatic ecosystems in several ways, including by potentially increasing bioavailability of a potent neurotoxicant, methylmercury. This talk investigates whether exposure to hypoxia results in elevated Hg concentrations in fishes via changes in trophic structure. Dr. Razavi's lab's approach involves a novel combination of tools to track hypoxia and mercury exposure, namely the combined use of fish otolith and eye lens microchemistry. They present a comparison of round goby (Neogobius melanostomus) and yellow perch (Perca flavescens) from the Western and Central Basins of Lake Erie, basins that experience large differences in extent and intensity of hypoxia. They find that benthic round goby exhibit greater hypoxia exposure in the Central Basin, and that elevated hypoxia exposure coincides with elevated Hg exposure as determined from their eye lens approach. Central Basin yellow perch showed little exposure to hypoxia and correspondingly low Hg exposure. They also find differences in food web position between basins for round goby, suggesting that hypoxia restricts diets. Otoliths and eye lenses offer powerful insights into fish life history as they provide chronometric resolution at the lifetime scale of an individual.