“Monitoring” Water Quality in Lake Simcoe Since Deglaciation Using Palynomorphs

Session: 56. - Science for a Healthy Lake Simcoe

Francine McCarthy, Brock University, [email protected]
Nicholas Riddick, Brock University, [email protected]
Olena Volik, University of Waterloo, [email protected]
Donya Danesh, Queens Univ., Dept. Biology, PEARL Lab, [email protected]

Abstract

Sediment archives preserve chemical and paleontological records of paleoenvironmental conditions, extending well beyond the limits of instrumental records. The acid-resistant remains of algae remain an underutilized paleolimnological proxy, despite their common presence in slides prepared for pollen analysis.  Additionally, these organic-walled microfossils are not subject to dissolution, unlike better-known mineralized algae like diatoms and chrysophytes, so they are present in statistically valid numbers in sediments deposited in Lake Simcoe since deglaciation whereas siliceous microfossils are largely restricted to sediments deposited over the last 150 years.  The remains of colonial chlorophytes, dinoflagellates, and particularly desmids, record both natural (climate-driven) and anthropogenic eutrophication in Lake Simcoe, with the latter beginning prior to European settlement.  Changes in desmid assemblages well below the rise in ragweed pollen in a core from Smith’s Bay record an increase in siltation as well as nutrient-enrichment attributed to a Wendat agriculture.  Pollen of cultivars and fungal spores of their pathogens as well as increased microcharcoal are consistent with impact from a Rock Tribe (Arendarhonon) village in the Smith’s Bay watershed between ~AD 1590 and 1650.

1. Keyword
eutrophication

2. Keyword
aboriginal

3. Keyword
Lake Simcoe