Terms of Reference

Review of the applicability of Habitat Suitability Index (HSI) model and Habitat Assessment Tool (HAT) for assessment of Westslope Cutthroat Trout habitat characteristics and associated productivity

Regional Science Response Process – Pacific Region

August 2015
Nanaimo, British Columbia

Chairperson: Lesley MacDougall

Context

Teck Coal Limited has proposed the development of three new coal mining areas which would expand the existing operating areas of Line Creek, Fording River and Coal Mountain, all located near Sparwood BC.  The Provincial Environmental Assessment (EA) for the Line Creek Phase II Expansion is complete, with construction underway.  The Fording River and Coal Mountain Phase II Expansions are currently under Provincial EA review.  The majority of the proposed developments occur within the Dry Creek, Lake Mountain Creek, and Wheeler Creek drainages respectively. Teck Coal currently has two existing Fisheries Act Authorizations associated with the Line Creek Operations, which require "offsetting" to be identified to counterbalance potential serious harm to fish that are considered a part of a commercial, recreational or aboriginal (CRA) fishery.  One of the key species considered a part of a CRA fishery in the Fording River area is the Westslope Cutthroat Trout, Oncorhynchus clarkii lewisi.  Westslope Cutthroat Trout are a popular freshwater sport fish in western Canada, and is a Province of British Columbia managed fish resource. The British Columbia population of Westslope Cutthroat Trout is listed as Species of Special Concern by the Committee of the Status of Endangered Wildlife in Canada (COSEWIC). Westslope Cutthroat are also identified as an indicator species of general ecosystem health, due to their restrictive habitat requirements (COSEWIC, 2006).

Proposed offsets for these developments will require assessment of the Fording River and tributaries to develop a greater understanding of Westslope Cutthroat Trout populations and limiting habitats affecting productivity.  As a component of this assessment, Teck Coal Resources has developed and submitted a Habitat Suitability Index (HSI) model and a Habitat Assessment Tool (HAT) model for review by the Fisheries Protection Program (FPP).  FPP will review the proposed models to determine whether they are appropriate as tools to evaluate project effects, and potential benefits of offsetting measures.

In general, Habitat Suitability Indices are curves used to quantify and evaluate habitat quality for a specific species, based on the known selection of particular habitat conditions during specific periods of the species’ life history (Larocque et al. 2014). The curves are therefore applicable only to the life stages and areas that are specified in the model, and for which field data has been obtained.  In the absence of such field data, HSI curves from other regions have been adapted and applied in some cases; but adapted HSI information may not be appropriate for other areas, habitats or species (Larocque et al. 2014).  Additionally, the method by which composite indices are developed from individual variables will produce different estimates of habitat suitability. FPP is reviewing the applicability of the HSI and HAT models as part of the Fisheries Act authorization process; specifically their ability to determine productivity of habitat, identify limiting habitats and assess population response from potential management strategies and offset actions for Westslope Cutthroat Trout.  The finalized HSI and HAT would be considered tools to prioritize management actions and habitat offset actions that would benefit the productivity of the Fording River Westslope Cutthroat Trout population.

The Province of British Columbia has provided incremental reviews and advice to the Proponent regarding the development and application of both HSI and the HAT models, and the subsequent validations both in informal technical reviews and as participants in the Fording River Operations Swift Project Fish and Fish Habitat Working Group. The HSI and HAT models, and an assessment of the models by the BC Ministry of Environment, were presented to the Elk Valley Fish and Fish Habitat Committee, which is comprised of the Proponent, Provincial and Federal regulators, and the Ktunaxa First Nations.

FPP is requesting that Science Branch assess the proposed HSI and HAT models as suitable tools to quantify habitat suitability and productivity, and predict population response of Westcoast Cutthroat Trout and provide advice on the applicability of these assessment models to other CRA fisheries, for various potential management strategies.  Science advice will help FPP biologists to critically determine if the models’ inputs, assumptions and parameters are acceptable, and under what circumstances; also whether these tools are effective in predicting population responses to various habitat management strategy and offset manipulations.

Objectives

The following Science Response will review the following documents:

• Results of 2012-2014 Westslope Cutthroat Trout Habitat Suitability Model Validation, Report # 1412994, Golder Associates, June 2015.
• Smyth, E., M. Sparling and T. Hatfield.  Habitat Assessment Tool for the Upper Fording Westslope Cutthroat Trout Population.  Consultant’s report prepared for Teck Coal Limited by Ecofish Research Ltd., August 22, 2014.

to address the specific objectives as outlined below.

1. Review the inputs, parameters and assumptions of the Habitat Suitability Index (HSI) and provide advice regarding the adequacy of the HSI Version 5 Models as surrogates of fisheries productivity when considering project related impacts to Westslope Cutthroat Trout and their habitats and corresponding offsets. Include a discussion of uncertainties and data gaps.
2. Review the inputs, parameters and assumptions of the Habitat Assessment Tool (HAT) and provide advice regarding the adequacy of the HAT to determine limiting habitats and to assess the population response of the Upper Fording Westslope Cutthroat Trout population from potential management and strategies and offset actions.  Include a discussion of uncertainties and data gaps.
3. Provide recommendations and advice consistent with recent National guidance regarding the use of these tools as a suitable proxy for future projects to determine fisheries productivity when considering impacts to fish and fish habitat of a CRA fishery and corresponding offsetting proposals.

Expected Publication

• Science Response

Participation

• Fisheries and Oceans (DFO) Science Branch Pacific Region
• DFO Fisheries Protection Program, Ecosystem Management Branch Pacific Regions

References

Larocque, S.M., C. Hatry, and E.C. Enders. 2014.  Development of habitat suitability indices and bioenergetics models for Arctic grayling ( Thymallus arcticus).  Can. Tech. Rep. Fish. Aquat. Sci. 3097: vi + 57p.

COSEWIC, 2006.  COSEWIC assessment and update status report of the westslope cutthroat trout Onchorhynchus clarkii lewisi (British Columbia population and Alberta population) in Canada.  Committee on the Status of Endangered Wildlife in Canada. Vii + 67pp.