Understanding Impacts of Environmental Change on Lake Champlain Water Quality Andrew Schroth

20th Century Environmental Change Preserved by Lake Sediments 2010 20th Century Eutrophication: Increasing Carbon, Phosphorus, Bloom Indicators Ag. Intensification ~1970 (Missisquoi Basin) Urbanization ~1960 (St. Albans) Sewer Expansion ~1900 (St. Albans) Europeans Arrive 1690

Changes Revealed by Long-Term Monitoring Program 1992-present Detected Change: Decreasing River N Increasing River P Decreasing Wind Increasing Discharge Increasing Temp. Lake Response: Total N Total P TN:TP Bottom Line:

Conceptual Model from Long-Term Monitoring: Opportunities to Prioritize and Partition Efforts! Most sensitive to internal nutrient loading and changes that impact that process Control sediment P input and manipulate conditions/composition of lake sediments Most sensitive to changes in river dissolved nutrient concentrations Focus on suppressing dissolved nutrient loading from rivers

High frequency monitoring tells us more about agents and impacts of change Algal Blooms Environmental Conditions(weather, lake physics, chemistry) Combinations of biological, physical, chemical sensors allow us to understand the complex relationship between weather, lake and river flow, chemistry and biology and drivers of change

Thank You! Contact: Andrew.Schroth@uvm.edu