AN ECOLOGICAL CURRENCY APPROACH TOWARDS RESOURCE IMPROVEMENT IN THE GLB

The GLB is an important but degraded natural resource. To protect this resource while still allowing for new/increased water withdrawals, the Great Lakes States Governors and Premiers signed the Great Lakes Charter Annex of 2001 establishing a new resource-based decision standard.1 This research relates to implementation of the resource improvement standard under provisions of the Annex. The research was initiated by identifying the five most common types of hydrologic-ecological systems in the GLB that were potentially vulnerable to withdrawals as well as amenable to improvement actions. These five systems included:Coastal wetlandsOpen lakeTributaries and riversEmbaymentsShorelineGroundwater systems were also important, however they were primarily accounted for through their influence on surface waters. With improvements to these systems in mind, this paper reports on research related to how the ecological currency approach is being used to quantify resource improvement, using five hypothetical new water withdrawal/resource improvement scenarios. One tool in this approach is the Habitat Equivalency Analysis (HEA) method, which uses a mathematical model and ecological metrics or “currencies” to calculate the changes in valued ecological functions and services due to the proposed action. An important aspect of this research involved developing the appropriate ecological currencies to measure the changes in functionality of the habitats that would, in turn, affect the ecological services that could be provided by those habitats. These ecological currencies are then used to quantify the gains and losses in valued ecological services due to the proposed withdrawals and the hydrologicecological restoration and enhancement actions, to help make a determination that will produce a net gain.Investigations through the use of new GLB withdrawal and resource improvement scenarios revealed that the resource improvements from a wide range in withdrawals can be adequately assessed primarily using the following 4 metrics:Loading of pollutants that degrade water qualityIntegrated numerical index of stream habitat functionalityMeasure of similarity to the natural, predevelopment flow regimeIntegrated numerical index of wetland habitat functionalityIt was concluded that resource improvements can be demonstrated in many ways ranging from qualitative descriptions to the use of formal quantitative models. Quantification may not be necessary, but it may add value for the applicant, the reviewers and other stakeholders. Quantification leads to greater predictability in decisions, optimizes and finds least cost solutions, and provides a consistent, systematic, and defensible process.