What Happens When No One is Watching? Ecological and Institutional Considerations for the Long-Term Management of Compensatory Wetland Mitigation in the Western Washington Coastal Zone

Abstract

Once compensatory wetland mitigation projects meet their permit criteria they are expected to last in perpetuity and are presumed to be self-sustaining. However, once projects are beyond their period of regulatory obligation there is rarely any follow up to determine how the projects ultimately end up. Recently, federal mitigation guidance has introduced a long-term management requirement, recognizing that to presume projects will continue to be successful without any long-term care may be flawed. Between 1999 and 2002 the WA State Department of Ecology conducted a Wetland Mitigation Evaluation Study to evaluate the effectiveness of compensatory wetland mitigation across the state. Projects evaluated were all less than ten years old and were still within their period of regulatory obligation. This thesis research revisited a subset of the mitigation projects used in Ecology's study to explore what has happened to them ecologically and institutionally in the ten years since the study, and to identify what can be learned from those projects to inform long-term management practices. Office and field investigations were performed for nine mitigation projects. Current ecological function of the sites was assessed and a functional comparison of the sites from 2002 to now was completed as well as a review of the institutional conditions surrounding the sites and their management. Relevance of the current site conditions to the overall intention of the mitigation are discussed and recommendations given for considerations to include in the development of long-term management guidance. This research shows that mitigation areas evolve over time due to both internal processes and external influences and that once permit criteria are met, the ecological trajectory of sites does not necessarily match that of the mitigation design. Institutional consistency was found to be lacking among the mitigation sites investigated and transfer of long-term stewardship responsibility to a third party group is recommended to help improve long-term outcomes.