CS27 Paleolimnology and Paleooceanography
Date: Tuesday, June 11, 2002
Location: Poster Session - VCC
 
HolthamAJ, P.E.A.R.L., Dept. of biology, Queen's University, Kingston, Canada, holthama@biology.queensu.ca
Michelutti, N, , P.E.A.R.L., Dept. of biology, Queen's University, Kingston, Canada, michelut@biology.queensu.ca
Douglas, M, S, P.A.L., Dept. of geology, University of Toronto, Toronto, Canada, msvd@opal.geology.utoronto.ca
Smol, J, P, P.E.A.R.L., Dept. of Biology, Queen's University, Kingston, Canada, smolj@biology.queensu.ca
 
PERIPHYTIC DIATOM ASSEMBLAGES FROM ARCTIC LAKES AND PONDS ON VICTORIA ISLAND, CANADA
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Autecological information on diatoms in high latitude regions is important, as they may be one of the best methods for tracking environmental changes in regions logistically difficult to monitor on a routine basis. In this study, epilithic, epiphytic, and surface sediment diatom assemblages were identified from 34 lakes and ponds on north-central Victoria Island, Canada. Over 200 taxa and 24 genera were identified. The ultra-oligotrophic nature of these lakes and ponds distinguishes them from other arctic datasets, as mean phosphorus (1.3 μg/L) and chlorophyll a (0.4 μg/L) were among the lowest recorded in arctic regions. Also, DOC concentrations (often < 1 mg/L) were 2-3 times lower than those recorded at similar latitudes. Although only minor environmental gradients existed between sites, there were major differences in diatom assemblages among the lakes and ponds. Also, several taxa were noted as being specific to only one microhabitat. Variance partitioning was performed to determine what percentage of species variation could be explained solely by water chemistry or solely by substrate. The combination of low nutrient and DOC concentrations suggests that taxa within these sites are already extremely stressed, and should be especially responsive to future environmental changes.