A physical and spatial assessment of remediated submerged habitats within the Thunder Bay area of concern

Abstract

The designation of Thunder Bay’s Harbour as an Area of Concern (AOC) by the International Joint Commission prompted the need for Remedial Action Plans to improve historically significant habitats (RAP, 1991; RAP 2004). In an attempt to restore, protect, conserve, and prevent further ecosystem degradation, a series of projects were developed with site-specific objectives to benefit the Thunder Bay AOC. The removal of contaminants, habitat compensation engineering, and species introduction was implemented to enhance the productivity of littoral zones and reduce areas of degraded habitat along the industrialized shoreline (RAP, 1991; RAP 2004). A multi-methodological approach is applied in this study to assess the physical and spatial habitat characteristics of six rehabilitation projects executed by the Thunder Bay Remedial Action Plan team (RAP) including McKellar Embayments, Neebing-McIntyre Floodway, Northern Wood Preservers Alternative Remediation Concept, Sanctuary Island, Current River, and North Harbour. A habitat classification framework is applied to utilize specific habitat indicators to rank sites based on their fisheries value and role in littoral zone regeneration and recovery. The majority of the projects were successful in improving habitat complexity, receiving a moderate to high ranking in the habitat classification. Further improvements in buffer zone extent, diversity, and thickness would benefit the aquatic ecosystems and would improve overall habitat scoring. River habitats, such as Neebing- McIntyre, require more extensive work to achieve outlined restoration goals as the embayment features did not have the desired outcome. Continued monitoring and management will ensure the success of these sites and provide evidence to support ongoing habitat restoration efforts in the Remedial Action Plan Program.