Canada’s policy for conservation of wild pacific salmon: stream, lake, and estuarine habitat indicators

Abstract

Strategy 2 of the Wild Salmon Policy (WSP) requires an assessment of habitats associated with salmon Conservation Units (CUs) within the Pacific Region. Habitats that support or limit salmon production within CUs are to be identified and indicators selected to assess these habitats. This paper focuses on the development of the proposed suite of habitat indicators and their related metrics and benchmarks. A consultative strategy was used to identify potential habitat indicators, which involved the creation of a Habitat Working Group (HWG) consisting of expert practitioners drawn from habitat management (principally) and habitat science backgrounds. The HWG systematically applied their knowledge and experience to review and select indicators to track spatial and/or temporal trends in the status of habitats used by wild salmon. Targeted reports were also commissioned by the HWG to further consolidate and ultimately filter down a large, potential list to a relevant subset of habitat indicators that could be feasibly developed for long-term Strategy 2 monitoring. A Pressure-State model was employed to partition indicators into two monitoring streams. Pressure indicators describe external (generally man-made) stressors that would be monitored over broad geographic areas. State indicators describe habitat condition, with related monitoring conducted within areas where pressure indicators indicate potential habitat problems. Nineteen habitat indicators were proposed for Strategy 2 monitoring of streams, lakes and estuary habitats: 7 pressure indicators (land cover alteration, road development, water extraction, riparian disturbance, marine vessel traffic, estuary disturbance, and permitted discharges), 8 state indicators (suspended sediments, water quality, water temperature, stream discharge, lake productive capacity, coldwater refuge zone, estuary chemistry and contaminants, and estuary dissolved oxygen), and 4 indicators of habitat quantity (accessible stream length, stream key spawning area, lake shore spawning area, and estuary habitat area). Quantitative metrics were identified to consistently measure the selected indicators for comparison to benchmarks. Where possible, benchmarks for the metric of each pressure and state indicator were defined based on the risk of adverse effects. Where risk could not be specifically defined, alternative benchmarks such as comparisons over time or space were recommended. Related monitoring is intended to track the status and trends of salmon habitats in CUs. Next steps include filling existing data gaps, defining an overall assessment framework, and linking habitat monitoring to salmon population and ecosystem monitoring under Strategies 1 and 3 of the WSP. Remaining challenges include determining how to combine and roll-up information from the suite of selected pressure, state and habitat quantity indicators to assess overall habitat status within a CU.