The 'Queen of American Lakes': palynological indicators of human disturbance in the Lake George watershed

Session: Poster Session

Paul Michael Pilkington, Brock University, [email protected]
Francine McCarthy, Brock University, [email protected]
Caitlin Garner, Brock University, [email protected]
Andrea Krueger, Brock University, [email protected]
Krystyna Kornecki, Griggs-Lang Consulting Geologists and Engineers, P.C., [email protected]
Miriam Katz, Rensselaer Polytechnic Institute, [email protected]

Abstract

Lake George is the EPA standard for freshwater in North America with its clear, oligotrophic water, and this headwater lake drains into Lake Champlain and the Richelieu River. Its paleoenvironmental history can be reconstructed from the remains of algae in slides processed for pollen analysis. Algal palynomorph assemblages record more eutrophic conditions in the more heavily populated southern basin of Lake George, and nearshore and deep basin samples also have a different palynological signature. Assemblage changes in a sediment core taken from near the Darrin Freshwater Institute’s continuous monitoring station off Tea Island record human impact on southern Lake George. An increase in pollen of non–arboreal plants and microcharcoal records land clearing by European settlers in the mid – late 19th C. The dinophyte Parvodinium umbonatum and the chlorophyte Pediastrum integrum in sediments below the Ambrosia rise record oligotrophic conditions. The chlorophyte Botryococcus, dinophytes Peridinium spp. and Parvodinium inconspicuum, and cyanophytes Anabaena and Microcystis spp. in Ambrosia–rich sediments record increased nutrient influx, consistent with testate amoeba and diatom records in other sediment cores that Kornecki (2018) attributed to European settlement. Abundant Botryococcus in uppermost sediments may record salinification from road salt consistent with testate amoeba and diatoms records.