Lake Erie Millennium Network

Workshop 4.5A:

Lake Erie Land and Water - Clarifying the Urban - Eutrophication Linkage

LEMN Workshop 4.5A - "Lake Erie Land and Water - Clarifying the Urban - Eutrophication Linkage" was a binational workshop that was held at Geraldo’s at LaSalle Park, Burlington, Ontario on March 21st 2013. This workshop was sponsored by Environment Canada.

Workshop Resources

Workshop Purpose

Aquatic researchers have a series of explanations for the behaviour of nutrients that enter Lake Erie; for example the links between nutrients, Dreissenid mussels, and harmful algal blooms.

We also know that nutrients arrive in the lake via storm events. However, we lack an in-depth understanding of the key types and the regulators of nutrients and the transformations they undergo on the landscape.

We will look to workshop participants’ expertise to help us determine the relative importance of different agricultural practices and the effectiveness of management practices in regulating nutrient loads.

A key task of the workshop will be for participants to generate flow charts that summarize their understanding of the key sources and links; and identify the most important research needs.

The resulting information will be integrated into a lakewide 'conceptual map' that adds the roles of land-based activities to our picture of the eutrophication process in Lake Erie.

We hope that the research needs can result in future opportunities for collaborative projects.

The findings will also be especially useful for informing the Canadian and US teams negotiating revisions to the Great Lakes Water Quality Agreement.

Workshop Goal

In 2009, fuzzy cognitive maps (FCMs) were developed by participants in an IJC workshop, as well as a Lake Erie LaMP workshop, dealing with the issue of re-eutrophication in the Great Lakes (see IJC 2009 Eutrophication report and technical report). These maps present compelling holistic integrations of known causes and consequences of re-eutrophication, and both FCMs show the re-eutrophication problem is driven by external drivers (changes in the land) and internal drivers (changes in lake ecosystem structure). In both maps, “agricultural activities” and “urban development” appeared to be among the main external drivers of re-eutrophication, although due to the large scope of the original maps (from land activities to aquatic features), these variables were not explored in more detail. A subsequent workshop held in 2010 refined understanding of the primary causes and interactions relating agricultural activities to eutrophication.

This workshop is designed to further develop the current understanding of the causes and consequences of the recent re-eutrophication of portions of the Great Lakes, with a particular emphasis on the role of urban development in this system. The goal of the workshop will be to develop a new consensus fuzzy cognitive map that focuses on the different urban-related land-based pathways and variables driving re-eutrophication in the Great Lakes