Date of Award

5-2017

Document Type

Thesis

Department

Environmental Health Science

Thesis Advisor

Lee Newman

Comments

Recent publications confirm long term gaseous elemental and oxidized mercury deposition trends within the northeastern United States as decreasing. Ascertaining how mercury dynamics in ecosystems respond to acid rain deposition is important for aquatic ecology, and human exposure. Continually, previously low pH, and recovering Honnedaga Lake in the Adirondack Park in New York is only one of seven lakes with heritage New York State Brook Trout (Salvelinus fontinalis). In an effort to accelerate the processes of neutralization, and to identify methylmercury effects within the ecosystem, several tributaries within the Lake's Watershed were treated with lime. Macroinvertebrate samples taken from the lime treated tributary (T6) and reference tributaries (T6A and MBBR) of four functional feeding groups (i.e. predators, omnivores, scrappers, and shredders) were analyzed for methylmercury (ng/g dw) and stable isotopes. Only the omnivore functional feeding group had a significant relationship to methylmercury and 8 15N to support the bioaccumulating metal as a trophic position indicator (ANOVA, p < 0.05). Trophic positions were found to be 2.81 , 2.58, 2.39, and 2.38 for the predator, omnivore, scrapper, and shredder functional feeding groups, respectively. Methylmercury concentrations in macroinvertebrates only had a significant relationship with years (2013 - 2014) of treatment (ANO VA, p < 0.05). Furthermore, methylmercury concentrations were shown to have increased at both reference sites from 2013 to 2014 (ANO VA, p < 0.05). Further research is needed to clarify what occurs to macroinvertebrates and the associated food web following a liming application.

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