An Ecological Design for the 40th Avenue West Remediation-to-Restoration Project

Abstract

The lower 21 miles of the St. Louis River, the largest U.S. tributary to Lake Superior, form the 4856 ha St. Louis River estuary. Despite the effects of more than 100 years of industrialized and urban development as a major Great Lakes port, the estuary remains the most significant source of biological productivity for western Lake Superior, and provides important wetland, sand beach, forested, and aquatic habitat types for a wide variety of fish and wildlife communities. The lower St. Louis River and surrounding watershed were designated an 'area of concern' (AOC) under the Great Lakes Water Quality Agreement in 1989 because of the presence of chemical contaminants, poor water quality, reduced fish and wildlife populations, and habitat loss. Nine beneficial use impairments (BUIs) have been identified in the AOC, including: loss of fish and wildlife habitat, degraded fish and wildlife populations, degradation of benthos, and fish tumors and deformities. The St. Louis River Citizens Action Committee, now the St. Louis River Alliance (SLRA), was formed in 1996 to facilitate meeting the needs of the AOC. Following the recommendations of the St. Louis River AOC Stage II Remedial Action Plan, the SLRA completed the Lower St. Louis River Habitat Plan (Habitat Plan) in 2002 as 'an estuary-wide guide for resource management and conservation that would lead to adequate representation, function, and protection of ecological systems in the St. Louis River, so as to sustain biological productivity, native biodiversity, and ecological integrity.' The SLRA also facilitated development of 'delisting targets' for each BUI in the St. Louis River AOC in December 2008. The Habitat Plan identified several sites within the AOC with significant habitat limitations. One of these sites, the '40th Avenue West Habitat Complex' (approximately 130 ha; Figure 1), was identified by a focus group within the SLRA habitat workgroup as a priority for a 'remediation-to-restoration' project. The purpose of the 'remediation to restoration' process is to implement remediation activities to address limiting factors such as sediment contamination, followed by restoration projects that best complement the desired ecological vision. The focus group developed a general description of desired future ecological conditions at the 40th Avenue West Habitat Complex, hereafter referred to as the 'project area,' including known present conditions and potential limiting factors of the area. In addition, the focus group recommended a process to develop specific plans and actions to achieve the desired outcomes at the site. This report documents the first step in the 'remediation-to-restoration process being implemented at the '40th Avenue West Habitat Complex,' the development of an 'Ecological Design' for the project area, and a preliminary evaluation of those factors potentially limiting the realization of those habitat and other land use goals. This report is intended to serve as a basis for a subsequent feasibility study in which remediation alternatives will be evaluated along with restoration alternatives, which may achieve the habitat goals noted here. This project was funded under USFWS Cooperative Agreement Number 30181AJ68, and is part of the USFWS Environmental Contaminants Program's goal to address contaminant-related needs of the St. Louis River Area of Concern as part of the Great Lakes Restoration Initiative. To establish the basis of an 'ecological design' for the project area, researchers at the University of Minnesota Duluth's Natural Resource Research Institute (NRRI), in cooperation with USFWS, USEPA, MPCA, MNDNR, and other partners, sampled the project area from the late summer 2010 through spring 2011 to establish baseline information on sediment contamination, ecotoxicology, vegetation, sediment types, benthic macroinvertebrates, fish assemblage, and bird usage of the area. Vegetation, macroinvertebrates, and sediment characterization were also completed for five reference areas selected by project cooperators. These reference areas represent less disturbed locations having high or low wind and wave exposure that can serve to demonstrate restoration potential for the project area.