Revisiting the drivers of eutrophication and cyanobacteria blooms in Lake Champlain’s Northeast Arm

Lake Champlain has been the focus of extensive research and investment in recent decades, as the states and provinces within the catchment have attempted to protect and improve water quality in the lake.  In much of the lake, phosphorus concentrations remain stable. A notable exception is the large “Inland Sea” basin in the lake’s Northeast Arm, where phosphorus concentrations are significantly increasing and there are indications that there may be a regime shift occurring in the magnitude of seasonal internal loading. Using more than 30 years of consistent monitoring data coupled with several catchment and lake modeling approaches, we investigate lake water quality in the context of changing internal loads, spatially variable influence of external nutrient loads from several tributaries, and physical changes to the lake thermal structure resulting from climate patterns. Finally, we address the extent to which internal loading in the Inland Sea may contribute to chronic, severe cyanobacteria blooms in an adjacent shallow, eutrophic bay.

Primary Presenter: Peter Isles, Vermont Agency of Natural Resources (peter.isles@vermont.gov)

Authors:

Matthew Vaughan, Lake Champlain Basin Program  (mvaughan@lcbp.org)

Andrew Schroth, University of Vermont  (andrew.schroth@uvm.edu)

Kareem Hannoun, Water Quality Solutions  (khannoun@wqsinc.com)

Imad Hannoun, Water Quality Solutions  (ihannoun@wqs.inc.com)

Kelsey Colbert, NEIWPCC  (kelsey.colbert@partner.vermont.gov)

Asim Zia, University of Vermont  (asim.zia@uvm.edu)