|Citation||Porter, M et al. 2013. Wild Salmon Policy: Southern Chinook conservation units: habitat indicators report cards. Prepared for Fisheries and Oceans Canada.|
|Abstract/Description or Keywords||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.
Consultative work by DFO’s Habitat Working Group (HWG) described in Stalberg et al. (2009)
identified an initial set of currently feasible habitat indicators that could be used for long-term
Strategy 2 monitoring and to track spatial and/or temporal trends in the status of salmon
habitats. A Pressure-State model was employed to partition habitat 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 at
a much more localized scale and can be monitored in areas where either pressure indicators
identify potential problems or a detailed watershed scale habitat status report has identified
specific limiting factors.
Nineteen habitat indicators were proposed in Stalberg et al. (2009) for Strategy 2 monitoring of
streams, lakes and estuary habitats: 7 pressure indicators (total 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, length of key stream spawning area, length of lake shore spawning
area, and estuary habitat area).
Quantitative metrics were identified in Stalberg et al. (2009) that could allow measurement of
selected indicators for comparison to benchmarks. Where possible, benchmarks for the metric
of each pressure and state indicator were to be defined based on the risk of adverse effects.
Where risk thresholds could not be specifically defined, alternative benchmarks such as relative
rankings based on distribution curves of values over time or space were recommended.
Remaining challenges identified in Stalberg et al. (2009) included 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 salmon CU.
This report describes methods employed to implement a WSP Strategy 2 synoptic overview of
habitat risk for 35 wild salmon Chinook CUs that collectively make up British Columbia’s
Southern Chinook assemblage. The list of Southern Chinook CUs is provided in Appendix 1.
This work used currently available agency datasets for watershed-scale analyses of habitat
pressure and habitat quantity indicators identified for Strategy 2 monitoring in Stalberg et al.
(2009) and that were considered appropriate for describing Chinook salmon habitats.
For analyses undertaken in this report an increasing intensity of habitat pressures is considered
representative of increasing risk of adverse effects to Chinook habitats. A broad suite of
habitat pressure indicators have been quantified for this report and used to define relative risk of
adverse effects to Chinook habitat within CU watersheds. However it must be noted that the
actual “risk” to Chinook habitats and populations will in reality be a combination both of the
intensity/magnitude of habitat pressures and the sensitivity of the receiving waters and the
species of concern. CU summaries were therefore supplemented as possible with information
on the relative vulnerability of Chinook CUs to habitat pressures (vulnerability being based on
CU-specific life history characteristics and broader scale habitat influences). However, only a
small set of vulnerability indicators have been identified to date and while vulnerability ratings
for these indicators are presented in this report they have not been used formally to adjust the
CU watershed risk categorizations, which are based solely on habitat pressure indicators. Evaluation of habitat state indicators, which is necessary for determining the current on-theground
habitat condition of Chinook CUs, was beyond the scope of this project. This synoptic
overview of Southern Chinook is intended only as an initial filter to identify CUs that may be at
highest potential risk of habitat degradation (as indicated by the status of various pressure
indicators). Those CUs at significant risk would then warrant more thorough field-based
assessment. Habitat state indicators would be assessed in the subset of identified higher risk
CUs as part of more data intensive Habitat Status Reports and state indicator monitoring
(Stalberg et al. 2009).
|Regional Watershed||Coast Region|
|Sub-watershed if known|