LE3 .A278 2014

2014

Mallory, Mark
Spooner, Ian

Acadia University

Bachelor of Science

Honours

Environmental Science

Environmental & Sustainability Studies

The Border Marsh Region (BMR), located on the Isthmus of Chignecto, is a major feeding ground for waterfowl and contains significant coastal wetland systems. The purpose of this study was to examine various open water wetland sites across the BMR to explore the potential for bioaccumulation of Pb and As in higher trophic level species. A previous study indicated elevated Pb and As concentrations in bottom sediments at most wetland sites. Gastropods were chosen to sample as vectors for metal transfer to waterfowl and it was hypothesized that gastropods would accumulate these metals in similar concentrations to their bottom sediment. Eleven sites were sampled, and relative element concentrations in gastropods were analyzed using a XRF spectrometer and compared to sediment concentrations. Results showed there were no significant correlations between Pb and As concentrations in sediment and gastropods, however these concentrations distinguished sediment and gastropods between brackish ponds, freshwater ponds constructed by Ducks Unlimited Canada and a freshwater lake. Although Pb and As concentrations in gastropods were not toxic, there were three important observations: i) the greatest proportions of Pb and As concentrations in gastropods to sediment were detected in the natural brackish ponds, ii) As was detected in gastropods from all sites whereas Pb was only detected in gastropods from the brackish ponds and the freshwater lake, and iii) As concentrations in gastropods were higher in recently constructed freshwater ponds. Wetland chemistries, and/or gastropod physiologies are likely critical factors in determining whether Pb and As will bioaccumulate in gastropods, and warrant further investigation for wetland management strategies.

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https://scholar.acadiau.ca/islandora/object/theses:1113