Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi), British Columbia Population, in Canada
Table of contents
- Responsible Jurisdictions
- Part 1: Federal Addition to the “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia”, Prepared by Fisheries and Oceans Canada
- Additions to the Adopted Document
- Exclusions from the Adopted Document
- Part 2: Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia, Prepared by the British Columbia Ministry of Environment
Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi), British Columbia Population, in Canada
Westslope Cutthroat Trout
Fisheries and Oceans Canada. 2017. Management Plan for the Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi), British Columbia Population, in Canada. Species at Risk Act Management Plan Series. Fisheries and Oceans Canada, Ottawa. iv + 115 pp.
Important Note: British Columbia’s Ministry of Environment’s management plan (adopted under Section 69 of the Species at Risk Act) begins after page 7 of this document.
Additional copies can be downloaded from the Species at Risk Public Registry.
Cover illustration: Lucas Raptis.
Également disponible en français sous le titre « Plan de gestion de la truite fardée versant de l'ouest (Oncorhynchus clarkii lewisi), population de la Colombie-Britannique, au Canada »
© Her Majesty the Queen in Right of Canada, represented by the Minister of the Environment, 2017. All rights reserved.
ISBN ISBN to be included by SARA Responsible Agency
Catalogue no. Catalogue no. to be included by SARA Responsible Agency
Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.
Under the Accord for the Protection of Species at Risk (1996) the federal, provincial, and territorial governments agreed to work together on legislation, programs, and policies to protect wildlife species at risk throughout Canada.
In the spirit of cooperation of the Accord, the Government of British Columbia has given permission to the Government of Canada to adopt the “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia” (Part 2) under Section 69 of the Species at Risk Act (SARA). The federal Minister of Fisheries and Oceans and the Minister responsible for the Parks Canada Agency are the competent ministers under SARA. A federal addition is included which completes the SARA requirements for this Management Plan.
The federal Management Plan for the Westslope Cutthroat Trout, British Columbia population, in Canada consists of two parts:
Part 1: Federal Addition to the “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) in British Columbia,” prepared by Fisheries and Oceans Canada
Part 2: “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) in British Columbia,” prepared by the British Columbia Ministry of Environment
The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996) agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c.29) (SARA), the federal competent ministers are responsible for the preparation of management plans for species listed as special concern. They are also required to report on progress five years after the publication of the final document on the Species at Risk Public Registry.
The Minister of Fisheries and Oceans and the Minister responsible for the Parks Canada Agency are the competent federal Ministers for the Westslope Cutthroat Trout (British Columbia population) as per Section 65 of SARA. In preparing this Management Plan, the competent ministers have considered, as per Section 38 of SARA, the commitment of the Government of Canada to conserving biological diversity and to the principle that, if there are threats of serious or irreversible damage to the listed species, cost-effective measures to prevent the reduction or loss of the species should not be postponed for a lack of full scientific certainty. To the extent possible, this Management Plan has been prepared in cooperation with many individuals, organizations and government agencies, including the Province of British Columbia as per section 66(1) of SARA.
SARA Section 69 allows the Ministers to adopt all or part of an existing plan for the species if the Ministers are of the opinion that an existing plan relating to a wildlife species includes adequate measures for the conservation of the species. A provincial management plan (Part 2 of this document) for the Westslope Cutthroat Trout was provided as science advice to the jurisdictions responsible for managing the species in British Columbia. Fisheries and Oceans Canada, in cooperation with the Parks Canada Agency, has prepared a federal addition (Part 1 of this document) to meet the requirements of SARA. The federal Management Plan meets content and process requirements under SARA Sections 65, 66, 68 and 69.
As stated in the preamble to SARA, success in the conservation of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions and measures set out in this Management Plan and will not be achieved by Fisheries and Oceans Canada, the Parks Canada Agency, or any other party alone. The cost of conserving species at risk is shared amongst different constituencies. All Canadians are invited to join in supporting and implementing this Management Plan for the benefit of the Westslope Cutthroat Trout (British Columbia population) and Canadian society as a whole.
A SARA management plan includes conservation measures to ensure that a species of special concern does not become threatened or endangered. These conservation measures support the management objectives identified in the management plan. Implementation of this Management Plan is subject to appropriations, priorities, and budgetary constraints of participating jurisdictions and organizations.
Fisheries and Oceans Canada
Parks Canada Agency
Government of British Columbia
Fisheries and Oceans Canada would like to thank the British Columbia Ministry of Environment for leading the development of this Management Plan and for its close cooperation with the Department. Fisheries and Oceans Canada is also grateful to the Parks Canada Agency for cooperating in the development of the federal addition to this Management Plan.
PART 1: Federal Addition to the “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia,” prepared by Fisheries and Oceans Canada
Additions to the adopted document
Fisheries and Oceans Canada prepared the following additions to the provincial “Management Plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia” (Part 2 of this document, hereafter the “provincial management plan”) in order to address specific Species at Risk Act (SARA) requirements that are not fully addressed. These additions are considered part of the federal Management Plan for the Westslope Cutthroat Trout (British Columbia population) under SARA.
The following hyperlinks in the provincial management plan are available in English only (en anglais seulement):
- Un-numbered page: http://www.env.gov.bc.ca/wld/recoveryplans/rcvry1.htm
- Page i: http://www.env.gov.bc.ca/wld/recoveryplans/rcvry1.htm
- Page 2: FRPA, OGAA, Situation de conservation, Rangs internationaux, Cadre pour la conservation de la C.-B., Groupes d’action établis en vertu du CC
- Page 59: http://a100.gov.bc.ca/pub/eswp/, http://www.env.gov.bc.ca/fw/fish/guide/#Management, http://www.env.gov.bc.ca/esd/documents/ff_program_plan.pdf (PDF 2,39 MB),www.env.gov.bc.ca/skeena/qws/docs/SkeenaAnglingManagementPlan.pdf (PDF 1,23 MB), http://www.env.gov.bc.ca/conservationframework/index.html, http://www.env.gov.bc.ca/wat/wq/#objectives,http://publications.gc.ca/collections/collection_2007/ec/CW69-14-506-2007F.pdf (PDF 1,05 MB)
- Page 60: www.gofishbc.com/documents/pdf/RAINBOW_TROUT_STRAINS.pdf (PDF 398,96 KB)
- Page 61: http://www.natureserve.org/publications/ConsStatusAssess_StatusFactors.pdf (inactive)
- Page 62: http://www.fwresearch.ca/Library.html, http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/00_96488_01, http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/00_02069_01, www.env.gov.bc.ca/fw/fish/pdf/Steelhead%20Stream%20Classification%20Policy.pdf (PDF 79,17 KB), http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/00_08036_01, www.gov.bc.ca/arr/reports
Strategic environmental assessment
A Strategic Environmental Assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of an SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or achievement of any of the Federal Sustainable Development Strategy’s (FSDS) goals and targets.
Management planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that implementation of management plans may inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non-target species or habitats. The results of the SEA are incorporated directly into the Management Plan itself (Section 10), and are also supplemented by the statement below.
This Management Plan is expected to benefit the environment by promoting the long-term persistence of the Westslope Cutthroat Trout within its native range, thereby contributing to FSDS Goal 4 (Conserving and Restoring Ecosystems, Wildlife and Habitat, and Protecting Canadians). The recommended actions identified in this plan address threats such as small and large scale habitat modifications, altered flow regimes, riparian alteration, and in-stream habitat modifications, contributing to Goal 3 (Water Quality and Water Availability) of the FSDS. By addressing these threats, the recommended actions will potentially provide benefits to other species that are present, further contributing to FSDS Goal 4 (Conserving and Restoring Ecosystems, Wildlife and Habitat, and Protecting Canadians). Finally, in addressing the maintenance of wild populations at abundance levels that prevent at-risk status assessment (Objective 2) this plan contributes to FSDS Goal 5 (Biological Resources, i.e. sustainable production and consumption of biological resources).
Given the considerations outlined above, the benefits of this Management Plan to the environment and other species are expected to far outweigh any adverse effects that may occur.
Elk Valley water quality plan
In Section 8.2.1 (Threat #3, second bullet, following the period) the following text is added:
In 2014, the British Columbia Ministry of Environment approved the Elk Valley Water Quality Plan (Teck Resources Limited, 2014). The plan was developed to address the management of water quality constituents released by mining activities throughout the Elk River watershed.
According to Section 72 of SARA, the Minister of Fisheries and Oceans must assess a management plan’s implementation five years after the plan is included in the Species at Risk Public Registry, and in every subsequent five-year period, until its objectives have been achieved. Fisheries and Oceans Canada supports the British Columbia Ministry of Environment’s approach (Section 9.5) to use Essential activities (Section 9.4, Table 10) as benchmarks and performance measures to evaluate progress. This supports the achievement of Management Objectives and acknowledges that the completion of Essential activities will inform knowledge gaps currently limiting the refinement of targets (Section 6.2, Table 2) and non-Essential activities (Section 9.4, Table 10). The use of alternative benchmarks and performance measures, as well as the refinement of targets, non-Essential activities and their associated timelines may be proposed in subsequent Management Plan updates.
Record of cooperation and consultation
This federal Management Plan is compliant with Section 66 of SARA. The Province of British Columbia, Fisheries and Oceans Canada, and the Parks Canada Agency cooperated on the preparation of the Management Plan (Parts 1 and 2) via the regional federal-provincial Species at Risk Coordinating Committee established under the Canada-British Columbia Agreement on Species at Risk (2005) (PDF 1,46 MB). Part 2 has been developed by the Province of British Columbia, to the extent possible, in cooperation with multiple organizations (see Part 2: Acknowledgements) including Fisheries and Oceans Canada and the Parks Canada Agency.
The federal Management Plan for Westslope Cutthroat Trout (British Columbia population) was posted to the DFO Pacific Region Consultation Website for a public comment period from October 7 to November 24, 2014. A draft of the Management Plan, along with background information and a comment form, was made available on the website. Letters were mailed, e-mailed and faxed to First Nations organizations in the species’ range requesting input on this draft Management Plan and offering an opportunity to request further discussion with Fisheries and Oceans Canada. E-mail notifications of the consultation were also sent to the Province of British Columbia, the United States Fish and Wildlife Service, regional and municipal governments, environmental interest groups, academia, industry, recreational fishery groups, and other stakeholder groups in the species’ range. The general public was notified by social media tweets.
Comments were received from 7 respondents during the consultation period in the form of a hardcopy letter, emails and online comment forms. Respondents included a landowner, a recreational fishery organization, a non-government environmental organization, industrial organizations, and a municipality. Primary topics discussed include: threats; fishery enforcement; hatchery practices; knowledge gaps; provincial and federal jurisdictions; stewardship; habitat compensation; and the socio-economic impacts of implementing the Management Plan. All feedback received during the consultation period is considered in developing the final Management Plan.
Teck Resources Limited. 2014. Elk Valley water quality plan. Teck Resources Limited, Sparwood, British Columbia. xxxii + 256 pp.
Exclusions from the adopted document
|Relevant Sections of Provincial Management Plan (Part 2)||Excluded Text|
|“Robust, wild fish populations are the foundation of a sustainable fisheries program, which in turn provides social, economic, and recreational benefits to the province.”|
|“. . . and providing sustainable societal benefits including quality fishing opportunities . . .”|
|“. . . at abundance levels capable of providing sustainable benefits to society, within the context of broader ecosystem values.”|
|“. . . so that the populations can provide sustainable societal benefits . . .”|
|“The Province of British Columbia has a global responsibility, as well as a responsibility to its stakeholders, to ensure that this resource is protected in B.C. and continues to support a diversity of recreational opportunities.”|
|All, except: “A provincial management plan for Westslope Cutthroat Trout is essential for federal and provincial government to achieve goals in natural resource management.”|
|“. . . , which in turn provide social, economic, and recreational benefits to the province. Implicit in this management plan is that the conservation goal must be met first to achieve the recreational goal . . .”|
|“. . . and recreation objectives . . .”|
“. . . ; and
All, except the following:1
|“. . . that can provide sustainable societal benefits . . .”|
The following Sub-Sections:
|“. . . following, at a minimum, province-wide (Province of British Columbia 2010), and Ministerial guidelines for consultation . . .”|
|“. . . be consistent with the B.C. Freshwater Fisheries Program Plan goals (B.C. Ministry of Environment 2007), and . . .”|
|“Sustainable and Diverse Recreational Opportunities” and everything beneath, except rows: 4, 7, and 9.|
|“. . . ; conservation is also the foundation upon which a sustainable recreational fishery can be maintained . . .”|
All, except the following excerpts:
Appendices 2 and 11 make several references to socio-economic considerations; however, they remain part of the federal Management Plan (unless otherwise stated in the table above) because they contribute to the technical basis from which objectives and targets were derived.
PART 2: Management Plan for the Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) in British Columbia, prepared by the British Columbia Ministry of Environment
Prepared by B.C. Ministry of Environment
BC Freshwater Fisheries Program
Updated - August 2014
About the British Columbia management plan series
This series presents the management plans that are prepared as advice to the Province of British Columbia. Management plans are prepared in accordance with the priorities and management actions assigned under the British Columbia Conservation Framework. The Province prepares management plans for species that may be at risk of becoming endangered or threatened due to sensitivity to human activities or natural events.
What is a management plan?
A management plan identifies a set of coordinated conservation activities and land use measures needed to ensure, at a minimum, that the target species does not become threatened or endangered. A management plan summarizes the best available science-based-information on biology and threats to inform the development of a management framework. Management plans set goals and objectives, and recommend approaches appropriate for species or ecosystem conservation.
Direction set in the management plan provides valuable information on threats and direction on conservation measures that may be used by individuals, communities, land users, conservationists, academics, and governments interested in species and ecosystem conservation.
For more information
To learn more about species at risk recovery planning in British Columbia, please visit the B.C. Ministry of Environment Recovery Planning webpage.
Management Plan for the Westslope Cutthroat Trout
(Oncorhynchus clarkii lewisi) in British Columbia
BC Freshwater Fisheries Program
Prepared by B.C. Ministry of Environment
Updated – August 2014
Table of contents
- Executive Summary
- 1. Introduction
- 2. COSEWIC Species Assessment Information
- 3. Species Status Information
- 4. Species Information
- 5. Vision, Goal, and Rationale
- 6. Management Objectives
- 7. Status of Meeting Management Objectives
- 7.1 Objective 1. Maintain the Native Distribution and Genetic Diversity of Populations
- 7.2 Objective 2. Maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits
- 7.3 Objective 3. Maintain, or Rehabilitate, the Capacity of Natural Habitat to Meet Abundance Targets for Populations
- 7.4 Objective 4. Optimize Sustainable Recreational Benefits
- 8. Threats
- 8.1 Threat Sources
- 8.1.1 Forest Harvest
- 8.1.2 Mining
- 8.1.3 Linear Projects
- 8.1.4 Agriculture
- 8.1.5 Residential, Recreational, and Commercial Development
- 8.1.6 Water Use - Permanent Water Withdrawal (Consumptive)
- 8.1.7 Water Use - Temporary Diversions/Dams (Non-Consumptive)
- 8.1.8 Fishing
- 8.1.9 Aquaculture, Hatcheries, and Stocking
- 8.1.10 Climate Change and Severe Weather
- 8.2 Threats Assessment
- 8.3 Threat Summary
- 8.1 Threat Sources
- 9. Current Management Framework
- 9.1 First Nations Interests
- 9.2 Habitat Management
- 9.3 Fisheries Management
- 9.4 Recommended Management Actions and Priorities
- 9.5 Management Plan Updates and Implementation Monitoring
- 10. Effects on Other Species
- 11. References
- Appendix 1: Habitat Use in the Elk River
- Appendix 2: Detailed Description of Framework and Derivation of Abundance Targets (to meet objective 2)
- Appendix 3: Defining Population Groups
- Appendix 4: Introgression
- Appendix 5: Abundance
- Appendix 6: Angling Mortality
- Appendix 7: Riparian Habitat Buffers
- Appendix 8: Natural Flow Conditions
- Appendix 9: Site Fidelity
- Appendix 10: Stream Crossings
- Appendix 11: Fishing Quality
- Appendix 12: Fish Stocking
- Appendix 13: Threats Assessment
List of figures
- Figure 1. Spatial representation of Population Groups for Westslope Cutthroat Trout
- Figure 2. Distribution of WCT observation data collected from lakes and streams within each Population Group.
- Figure 3. Distribution of hybridized WCT populations in southeast B.C. watersheds.
- Figure 4. Landscape-level assessment of flow sensitivity in different ecosections within assessed ecosections within the native range of WCT in B.C.
- Figure 5. Known stream crossings based on intercept analysis of road/rail x stream, within the WCT range in B.C. Crossings differentiated according to stream sections identified as fish-bearing or non-fish-bearing.
- Figure 6. Overview of all current and pending water licenses within the WCT range in B.C.
List of tables
- Table 1. Comparison of the number of streams and lakes (as defined by blueline coding in 1:20,000 stream network data; B. Woods, pers. comm.) in which WCT have been observed, as of June 2010, across Population Groups. Overall, most WCT observations occur in stream environments
- Table 2. Summary of available indicators, measures, targets, and status of meeting targets for each management objective.
- Table 3. Summary of road density by Population Group.
- Table 4. Summary of WCT CPUE on Quality Waters where effort has been reported over time
- Table 5. Comparison of license counterfoils with East Kootenay Angling Management Plan targets for Kootenay (B.C. Ministry of Environment 2006; Burrows 2007)
- Table 6. Summary of all stocking records for WCT, Rainbow Trout (RBT), Eastern Brook Trout (EBT), and Rainbow Trout x Cutthroat Trout crosses (RBT x CT) in the core range of WCT until 2008
- Table 7. Summary of medium and high rating threats for each Population Group
- Table 8. Summary of Population Groups with respect to trends, key threat mechanisms, and level of conservation concern
- Table 9. Legislative tools that may protect various aspects of fish habitat within WCT range
- Table 10. Summary of recommended actions considered critical in implementing the WCT management plan.
- Table A3.1 Defined Population Groups based on genetic data and delineated major drainages within native WCT range
- Table A4.2 Percent of populations considered to be pure WCT based on genotypic data by Population Group. Note that in some cases, the approximate location within the stream was reported by researchers (L = lower, M = Mid, U = upper), otherwise location was reported as “unknown.” (WCT = Westslope Cutthrout Trout, RBT=Rainbow Trout)
- Table A5.1 Summary of abundance and density estimates for WCT in a small set of streams from the Elk and Upper Kootenay Population Groups.
B.C. Ministry of Environment. 2014. Management plan for the Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) in British Columbia. Repr. of 1st ed., B.C. Ministry of Environment, Victoria, BC. 98 p. (Orig. pub. 2013)
Additional copies can be downloaded from the B.C. Ministry of Environment Recovery Planning webpage.
This is an updated version of the December 2013 first edition of this document.
See Updates for specific changes to the document.
Updated August 2014 - Changes to the original posting (December 2013) include: correction of FRPA and OGAA legal designation to “Species at Risk” (Section 3, pg.2); clarification of text in the “Details” column of Table 9; as well as minor formatting, grammatical and typographical corrections.
This management plan has been prepared by the B.C. Ministry of Environment, as advice to the responsible jurisdictions and organizations that may be involved in managing the species.
This document identifies the management actions that are deemed necessary, based on the best available scientific and traditional information, to prevent Westslope Cutthroat Trout populations in British Columbia from becoming endangered or threatened. Management actions to achieve the goals and objectives identified herein are subject to the priorities and budgetary constraints of participatory agencies and organizations. These goals, objectives, and management approaches may be modified in the future to accommodate new objectives and findings.
The responsible jurisdictions and all members of the management team have had an opportunity to review this document. However, this document does not necessarily represent the official positions of the agencies or the personal views of all individuals on the management team.
Success in the conservation of this species depends on the commitment and cooperation of many different constituencies that may be involved in implementing the directions set out in this management plan.
The B.C. Ministry of Environment encourages all British Columbians to participate in the conservation of Westslope Cutthroat Trout.
This plan was prepared by Sue Pollard (B.C. Ministry of Environment) with input from an adhoc working group during two provincial workshops for this species held in Cranbrook in January 2009 and December 2010. Workshop participation and contributions to the development of the plan came from a number of agencies, First Nations, and independent consultants including: B.C. Ministry of Environment, B.C. Ministry of Forestry, Lands and Natural Resource Operations, Parks Canada, Fisheries and Oceans Canada (Tom Brown), Canadian Columbia River Inter-Tribal Fishery Commission (Bill Green), Trout Unlimited (Jon Bisset), Freshwater Fisheries Society of BC (Doug Crawley), Alberta Fish and Wildlife (Jenny Earle), Scott Cope (Westslope Fisheries), Peter Corbett (Mirkwood Ecological Consultants), Mike Robinson (Lotic Environmental), Gerry Oliver (G.G. Oliver and Associates), and Bill Westover.
Additional reviewers included Ted Down, Leah Westereng, Greg Wilson, and the provincial Fisheries Policy Team. Staff from the Species at Risk group at Fisheries Oceans Canada provided valuable comments to better align this document with the requirements under Species at Risk Act (SARA).
Byron Woods provided GIS support and great maps.
Funding to support this management plan included contributions from the B.C. Ministry of Environment 2010 Habitat Conservation Trust Fund and Fisheries and Oceans Canada.
The Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisi) was designated as Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) due to concerns regarding introduced species (hybridization and competition), habitat loss and degradation, and increasing exploitation. It is listed as Special Concern in Canada on Schedule 1 of the Species at Risk Act (SARA). In British Columbia, the Westslope Cutthroat Trout is ranked S3 (vulnerable) by the Conservation Data Centre and is on the provincial Blue list. The B.C. Conservation Framework ranks the Westslope Cutthroat Trout as a priority 2 under goals 1 and 2 (contribute to global efforts for species and ecosystem conservation; and prevent species and ecosystems from becoming at risk).
In addition, Westslope Cutthroat Trout was identified as a priority native sport fish species by the BC Freshwater Fisheries Program in need of a provincial fisheries management plan. Robust, wild fish populations are the foundation of a sustainable fisheries program, which in turn provides social, economic, and recreational benefits to the province.
This document is intended to meet the needs of SARA, as well as the BC Freshwater Fisheries Program. The following are the vision, goal, and objectives of this management plan.
Abundant and diverse populations of Westslope Cutthroat Trout capable of persisting and providing sustainable societal benefits including quality fishing opportunities.
Overarching Management Goal
Long-term persistence of the species within its native range at abundance levels capable of providing sustainable benefits to society, within the context of broader ecosystem values.
The management objectives are to:
- maintain the native distribution and genetic diversity of populations;
- maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits;
- maintain, or rehabilitate, the capacity of natural habitat to meet abundance targets for populations; and
- optimize sustainable recreational benefits.
Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) arguably supports the most popular fisheries for native species in the southeast area of the province. In the past, liberal fishing regulations, in combination with other factors such as habitat degradation, have resulted in significant declines for at least some populations. Furthermore, the global distribution of the species has contracted significantly. At one time, the majority of the species’ distribution was outside of Canada; competition and hybridization issues with introduced sport species, and habitat loss and degradation have resulted in a much reduced distribution with the most extant populations residing in B.C. The Province of British Columbia has a global responsibility, as well as a responsibility to its stakeholders, to ensure that this resource is protected in B.C. and continues to support a diversity of recreational opportunities.
A provincial management plan for Westslope Cutthroat Trout is essential for federal and provincial government to achieve goals in natural resource management. First, this plan will accomplish activities that were highlighted as priorities under the goals of the provincial Freshwater Fisheries Program Plan. The three goals of the Freshwater Fisheries Program Plan are to (1) establish governance approaches that are strategic, effective, and efficient; (2) conserve wild fish and their habitats; and (3) optimize recreational opportunities based on the fishery resource (B.C. Ministry of Environment 2007). Implicit in the program is that conservation goals must be met first to achieve recreational and associated economic goals.
As part of the goal to “conserve wild fish and their habitats,” the need to develop species-based management plans to establish provincial-level objectives and management strategies for species that support recreation was identified. Furthermore, the goal to “optimize recreational opportunities based on the fishery resource” directs us to define objectives and establish the appropriate management approach using species-based summaries, stakeholder preferences, and resource assessments.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated the B.C. population of Westslope Cutthroat Trout as Special Concern in November 2006; in 2010 the B.C. population was legally listed under the federal Species at Risk Act (SARA)4. Under the SARA, species listed as Special Concern require a SARA-compliant management plan for the species and its habitat, including measures for the conservation of the species. The intent of this document is to address both federal and provincial planning needs in a single document.
2. COSEWIC* Species assessment information
Date of Assessment: November 2006
Common Name (population):** Westslope Cutthroat Trout
Scientific Name: Oncorhynchus clarkii lewisi
COSEWIC Status: Special Concern
Reason for Designation: Populations are stressed by hybridization and competition with introduced species. Furthermore, expanding urban development, agricultural activities and resource-based industries are expected to lead to additional stresses associated with habitat loss and degradation, as well as increased exploitation. It should be noted that this assessment includes only genetically pure, native populations of the species occurring within their historical range. Any populations know to be hybridized significantly (i.e., >1%) with other trout species, or to have been introduced into a system previously free of native populations, were not assessed.
Canadian Occurrence: British Columbia
COSEWIC Status History: Designated Special Concern in May 2005. Status re-examined and confirmed November 2006. Assessment based on a new status report.
* Committee on the Status of Endangered Wildlife in Canada.
** Referred to as Cutthroat Trout, lewisi subspecies by the British Columbia Conservation Data Centre.
3. Species status information
Westslope Cutthroat Trouta
Goal 1: Contribute to global efforts for species and ecosystem conservation.
Priority: h 2 (2009)
Goal 2: Prevent species and ecosystems from becoming at risk.
Priority: 2 (2009)
Goal 3: Maintain the diversity of native species and ecosystems.
Priority: 3 (2009)
- Compile Status Report; Planning; Send to COSEWIC; Habitat Protection; Habitat Restoration; Private Land Stewardship; Species and Population Management; Review Resource Use
a Data source: B.C. Conservation Data Centre (2012) unless otherwise noted.
b Species at Risk = a listed species that requires special management attention to address the impacts of forest and range activities on Crown land under the Forest and Range Practices Act (FRPA; Province of British Columbia 2002) and/or the impacts of oil and gas activities on Crown land under the Oil and Gas Activities Act (OGAA; Province of British Columbia 2008) as described in the Identified Wildlife Management Strategy (Province of British Columbia 2004).
c Schedule A = designated as wildlife under the B.C. Wildlife Act, which offers it protection from direct persecution and mortality (Province of British Columbia 1982).
d Schedule 1 = found on the List of Wildlife Species at Risk under the Species at Risk Act (SARA).
e S = subnational; N = national; G = global; T = refers to the subspecies level; X = presumed extirpated; H = possibly extirpated; 1 = critically imperiled; 2 = imperiled; 3 = special concern, vulnerable to extirpation or extinction; 4 = apparently secure; 5 = demonstrably widespread, abundant, and secure; NA = not applicable; NR = unranked; U = unrankable.
f Data source: NatureServe (2012).
g Data source: B.C. Ministry of Environment (2010).
h Six-level scale: Priority 1 (highest priority) through to Priority 6 (lowest priority).
4. Species information
4.1 Species description
Westslope Cutthroat Trout (WCT; Oncorhynchus Clarkii Lewisi) is a strictly inland subspecies of Cutthroat Trout. In B.C., there are two subspecies of Cutthroat Trout: WCT and Coastal Cutthroat Trout (O. clarkii clarkii). Dymond (1931) described a third subspecies in B.C., namely Mountain Cutthroat Trout or O. clarki alpestri, which was found in disjunct populations in mountain lakes of the Revelstoke area. These populations are now considered a form of Westslope Cutthroat Trout (McPhail 2007). Most taxonomists currently recognize 14 allopatrically occurring subspecies of Cutthroat Trout with 4 of these subspecies, including Westslope, Coastal, Lahontan (O. clarkii henshawi), and Yellowstone(O. clarkii bouvieri) showing substantial genetic divergence and broad distribution; the remaining 10 subspecies are of limited range. Many historic records refer to WCT as the inland form of Yellowstone Cutthroat Trout. However, major genetic and chromosome differences have confirmed that these two forms are distinct subspecies (in McPhail 2007). Yellowstone Cutthroat Trout is not native to Canada.
Key Distinguishing traits
Westslope Cutthroat Trout is one of two native subspecies of native Cutthroat Trout in B.C., the other being Coastal Cutthroat Trout.From Kookanusa Reservoir and upstream, it is one of only two native salmonids residing in southeastern B.C.; Bull Trout (Salvelinus confluentus) is the other species.
The main feature that distinguishes the B.C. populations of WCT from Coastal Cutthroat Trout is the pattern of spotting on the body–the spots for WCT below the lateral line are concentrated on the back half of the body and almost absent at the front. In Coastal Cutthroat Trout, irregular black spots are distributed evenly from front to back (McPhail 2007). The main feature that separates WCT from Rainbow Trout (O. mykiss) is the orange-red slash below the lower jaw plus a longer mouth that extends past the hind portion of the eye in WCT (COSEWIC 2006).
The WCT is primarily insectivorous, typically but not exclusively feeding on drifting invertebrates and nymphs in streams, and winged insects and zooplankton while in lakes and large rivers (McPhail 2007). Therefore, they influence benthic invertebrate community structure and trophic dynamics of the habitats they inhabit.
WCT are one of the few large native fish species adapted to cold, nutrient-poor streams within their native range in British Columbia. As WCT are rather fecund, eggs, juveniles, and adults can be abundant and preyed upon by other fish (bull trout, northern pikeminnow, cottids), many mammals (river otters, mink, bears), and birds (raptors, ducks).
WCT have strict habitat requirements of cool, clean, and well-oxygenated waters, connected habitats for different life stages with various natural habitat attributes, this makes them an indicator of ecosystem health and environmental quality indicator across the landscape. WCT were one of the first salmonids to recolonize western Canada (following glaciation). In most of their range there is only one other native species from the subfamily salmoninaes5; therefore, WCT play an important role in structuring north temperate ecosystems (McPhail and Carveth 1992).
WCT represent an important component of the cutthroat trout species complex. They are the subspecies at the northern periphery of the species range; inhabit a variety of extreme habitats; likely contain a number of unique specializations for cooler, less productive ecosystems; and occur in many different morphological and life-history forms (COSEWIC 2006; see section 4.3). These adaptations to marginal habitat might be necessary for reintroduction to extirpated areas, and as such constitute an important component of species biodiversity (COSEWIC 2006).
4.2 Populations and distribution
The historic distribution of WCT is not known with certainty (Behnke 1992; Prince 2001; McPhail 2007) but includes the upper Missouri River basin, and the Columbia River basin including the Kootenay River westward to the Cascade Mountains where it occurs as disjunct populations including those described as Mountain Cutthroat (Behnke 1992). It is thought to be one of the first post-glacial colonizers in many areas that were later extirpated except above barriers as Rainbow Trout recolonized these systems. This may explain the disjunct populations particularly in the western parts of its range in B.C. (McPhail 2007). Westslope Cutthroat Trout have experienced severe reductions in distribution in many areas of their native range in western North America owing to habitat loss, barriers, and negative interactions with introduced salmonids. In particular, their distribution is now limited to mainly cold headwater streams in most drainages in the northwest United States, as well as Alberta (Shepard et al. 1997; Mayhood 1999).
The core WCT range in B.C. occurs in the Kootenay, Flathead, and Pend d’Oreille systems, where WCT inhabit most major tributaries as well as smaller creeks and lakes. However, disjunct populations also occur in headwater streams and lakes of the upper Columbia River as well as a few tributaries of the South Thompson River and the Kettle River (Prince 2001; COSEWIC 2006; McPhail 2007).
Dymond (1931) described some isolated populations of Cutthroat Trout in the Revelstoke area (from both Columbia and Fraser tributaries) as a distinct subspecies: the Mountain Cutthroat Trout, Oncorhynchus clarki alpestris. These are undoubtedly WCT (Behnke 1992). The origins of these disjunct populations are unclear; one possibility is that the Fraser populations originated from movement from headwater Columbia tributaries nearby (McPhail 2007). However, genetic data that consider two Fraser and Columbia WCT populations in close physical proximity do not support this hypothesis as the two are genetically distinct (Taylor et al. 2003). The alternative is that WCT were once much more broadly distributed in the Fraser but were displaced and eliminated by naturally recolonizing Rainbow Trout (Dymond 1931). In this way, similar extirpations may explain why WCT are only present above barriers in a few small tributaries of the Kettle River (McPhail 2007).
Native WCT do not occur in the Okanagan River drainage. WCT have been stocked into many additional lakes and some streams, mainly in the B.C. Southern Interior within core and peripheral areas of the native range of the species.
4.2.2 Defining population groups
A significant amount of literature supports the use of units below the taxonomic species level to assist in the management and conservation of species where appropriate. Particularly for widespread species with spatially variable evolutionary histories and threats such as WCT, assessing conservation status at the species level is wholly inadequate to reflect the risk of extinction. Refer to Appendix 3, Defining population groups, for more detail.
We adopted a practical compromise between the discrete population level and species level to identify units (herein called Population Group) for status and threat assessment, as well as management considerations. Specifically, two key factors were considered in defining Population Groups for WCT in B.C.: genetic population structure and major drainages. This resulted in seven Population Groups, which are used to report out on status indicators and threat assessment results. However, management activities such as abundance estimates must still be undertaken at the population level. These Population Groups are not intended to be equivalent to more robustly defined units in the literature such as Conservation Units (Wild Salmon Policy, DFO), Designatable Units (COSEWIC), or Evolutionarily Significant Units (U.S. Endangered Species Act). These groups fall into two categories, core range and peripheral range, reflecting the extent to which native populations occur in these areas, as follows:
- Elk - Elk lakes to Elko Dam including all tributaries
- Flathead - Flathead from headwaters to border
- Upper Kootenay - Kootenay River and tributaries from headwaters to Kookanusa Reservoir. This set excludes the Elk River except for the very lowest portion below the natural barrier at Elko Dam; thus Wigwam River is included. Includes Kootenay National Park.
- West Kootenay - Kootenay Lake and tributaries including inlet (to border) and outlet (to Brilliant Dam)
- Columbia - entire Columbia River mainstem from headwaters to border including Pend d’Oreille. Includes Glacier and Yoho National Parks.
- Kettle - entire watershed
- South Thompson - upper portion of South Thompson watershed
The core range Population Groups represent the core or centre of distribution for WCT in B.C. while the other three Population Groups contain fairly disjunct, sparsely distributed populations considered more in the periphery of the native range. Further subdivision of Columbia Population Group into an upper and lower component (breakpoint at Mica Dam) was considered; however, WCT distribution within this area is scattered to begin with. Thus, additional groups in peripheral areas did not seem necessary. Figure 1 provides a spatial representation of these Population Groups.
Figure 1. Spatial representation of Population Groups for Westslope Cutthroat Trout.
Long Description for Figure 1
Figure 1 is titled “Spatial representation of Population Groups for Westslope Cutthroat Trout.” The map depicts the core range (Elk, Flathead, Upper Kootenay and West Kootenay Population Groups) shaded in green, and the periphery range (Columbia, Kettle and South Thompson Population Groups) shaded in grey of WCT in the southeastern corner of British Columbia. The border of each Population Group’s range is outlined by light tan lines. Water bodies are depicted with light blue colouration and cities are depicted by square grey points. A scale is provided in the lower right corner. An inset map shows the general location of Westslope Cutthroat Trout distribution relative to: the rest of British Columbia, the British Columbia-Alberta border, and the British Columbia-Washington State border.
4.2.3 Defining populations
Ideally, every population of WCT within each Population Group could be identified, characterized, assessed, and prioritized in terms of conservation and management objectives. This information could then be rolled up to provide an overall status evaluation and management direction at the Population Group level. However, such a detailed level of information is not, nor likely will be, available.
A total of 1,319 unique waterbodies (including both lakes and streams) at the 1:20,000 scale contain at least one WCT observation (Table 1; Figure 2). These data represent all observation data from the Fisheries Information Summary System (FISS). The number of observations that are truly representative of original native populations versus introduced populations via hatchery releases is very difficult to determine given the extensive hatchery history for WCT in B.C. Most waterbodies with observations, approximately 928, have no hatchery release records; therefore, currently there are an estimated 928 to 1,319 waterbodies that may contain WCT populations. The numbers are probably conservative as they only includes locations for which WCT have been observed and reported. Many small headwaters and lakes capable of supporting WCT remain to be surveyed. The last COSEWIC (2006) assessment estimated a probable range of 30–to 100 mature individuals per population, considering their biology, habitat preferences, and productivity. This assumes one population per smaller lake or stream, and several independent component stocks in larger systems.
In terms of life history variation, WCT have been observed in both lakes and streams for all Population Groups in B.C. (Table 1). Based on extracted observation data, more streams than lakes have been reported to contain WCT. Larger proportions of lake observations in peripheral areas may reflect a difference in habitat types available for WCT or a stocking history in lakes in areas where native populations are not so common. The presence of isolated headwater populations has only been confirmed in limited surveys where barriers have been identified. Some studies have explicitly noted the diversity of life history variation that occurs at the watershed level. For instance, an Elk River radio-tagging study confirmed the presence of all three WCT life history forms (Westslope Fisheries Ltd. 2003). In the St. Mary River, Oliver (1990) reported that fish spent two years in nursery streams before emigration to larger, more productive systems (i.e., (ad-) fluvial life history).
With respect to genetic population structure, results indicate that populations tend to cluster geographically and are associated with watersheds, with outliers being highly isolated headwater populations (Taylor et al. 2003). Significant divergence among populations even where genetic exchange is possible suggests strong demographic independence and a need to manage at a local population level, despite extensive movements often observed. For more detail, refer to Appendix 3, Defining Population Groups.
It is impossible to identify all WCT populations within each Population Group with the available observation data. Furthermore, it is unlikely that all waterbodies within the native range of WCT will ever be surveyed. However, a habitat-based modeling exercise could be undertaken to assess the potential number and distribution of waterbodies capable of supporting WCT in B.C. This would enable a more detailed characterization of WCT at the population level and an assessment of rarity (e.g., based on ecotype frequency) and conservation priority (e.g., based on genetic purity, isolation from introduced Rainbow Trout). Predictive modeling will enable a more representative assessment of the number of lakes versus streams within each group likely to support WCT. In addition, modeling that considers barrier presence will help identify headwater resident populations.
Long Description for Table 1
Table 1 is titled “Comparison of the number of streams and lakes (as defined by blueline coding in 1:20,000 stream network data; B. Woods, pers. comm.) in which WCT have been observed, as of June 2010, across Population Groups. Overall, most WCT observations occur in stream environments.” The table is read horizontally from left to right, and consists of five columns and nine rows. The top row contains the column headings: Population Group, Streams, Lakes, Total, and % Streams. The last row is titled “Total.”
|Population Group||Streams||Lakes||Total||% Streams|
Figure 2. Distribution of WCT observation data collected from lakes and streams within each Population Group.
Long Description for Figure 2
Figure 2 is titled “Distribution of WCT observation data collected from lakes and streams within each Population Group.” The map depicts the distribution of WCT using point observations (purple points are streams observations, and red points are lake observations). The border of each Population Group’s range is outlined by green lines. Water bodies are depicted with light blue colouration, cities are depicted by square grey points, and ranges and highlands are labelled with upper case letters. A scale is provided in the lower right corner. An inset map shows the general location of Westslope Cutthroat Trout distribution relative to: the rest of British Columbia, the British Columbia-Alberta border, and the British Columbia-Washington State border.
4.3 Needs of the Westslope Cutthroat Trout
The species typically occurs as one of three life history forms in B.C. (summarized by Oliver (2009):
- stream-resident – typical of headwater stream populations above barriers that complete their life cycle within a very restricted distribution and remain relatively small (i.e., < 200 mm in length) due to the cold, nutrient-poor nature of these small streams;
- fluvial – typical of migratory populations that move between small spawning/rearing tributaries and larger, more productive adult-rearing rivers and are thus generally larger as adults (i.e., > 400 mm in length); and
- adfluvial – typical of populations that migrate between spawning/rearing tributaries and adult rearing lakes where adults can exceed 500 mm in length if productivity in lakes is high.
Resident and fluvial populations frequently co-occur in the same watersheds in B.C. although barriers may separate populations (Oliver 2009). Adfluvial populations may occur in headwater lakes with inlets and outlets, as well larger downstream lakes like Kookanusa Reservoir and Kootenay Lake.
Rising temperatures and a rising hydrograph in the spring trigger spawning migrations, and spawning in B.C. usually occurs from early May to late June (McPhail 2007). Females build the redd, usually upstream of tail-out areas of glides or riffle sections (Schmetterling 2000). Fecundity varies with size; small headwater fish are reported to have about 125–700 eggs while larger lake and river fish have 750–2000 eggs (Downs and White 1997). WCT are iteroparous (they can spawn more than once); however, frequency of repeat spawning varies across populations, from <1% to about 25% (McPhail 2007).
Resident populations may reach maturation in 3 years, but most fish mature in their fourth year with females typically maturing 1–2 years later than males (Downs and White 1997). In fluvial and adfluvial populations, maturation may occur for males after 3–4 years; in females, maturity is reached by 5 years (McPhail 2007).
Unlike other cutthroat subspecies, WCT do not appear to be highly predacious on other fish (Behnke 1992). WCT are generally insectivorous although zooplankton may be important to populations of larger lakes (McPhail 2007). This may reflect the species’ co-evolution with two highly predacious species, namely Bull Trout (Salvelinus confluentus) and Northern Pikeminnow (Ptychocheilus oregonensis), such that it specialized as an insectivore to avoid competition (Behnke 1992).
Typical WCT streams are cold and nutrient poor (Liknes and Graham 1988). Specific habitat requirements vary with life history form and season including migration, spawning, incubation, rearing, and overwintering. Temperature and flow are key physical cues that trigger migrations for spawning and overwintering (Oliver 2009). High water quality, including adequate oxygen and clean, sediment-free gravel, is essential during the incubation period (Oliver 2009). Pool-to-riffle ratios will influence availability of rearing habitat, while adequate depths and temperature regimes will strongly influence overwintering survival (Oliver 2009). In fact, Oliver (2009) suggests that the availability of suitable overwintering habitat may be most limiting particularly for fluvial or small stream populations. Refer to Habitat Use in Appendix 1 for more details specific to the Elk River.
Westslope Cutthroat trout populations are naturally limited by their specific habitat requirements relating to water temperatures, stream hydrology, connectivity and the availability of specific habitat types, as described above.
5. Vision, goal, and rationale
Abundant and diverse populations of Westslope Cutthroat Trout capable of persisting and providing sustainable societal benefits including quality fishing opportunities.
Overarching management goal
Long-term persistence of Westslope Cutthroat Trout within its native range at abundance levels capable of providing sustainable benefits to society, within the context of broader ecosystem values.
5.1 Management goal rationale
Westslope Cutthroat Trout is identified as a priority native sport fish species by the BC Freshwater Fisheries Program. Healthy and persistent wild fish populations are necessary for achieving conservation goals and a sustainable fisheries program, which in turn provide social, economic, and recreational benefits to the province. Implicit in this management plan is that the conservation goal must be met first to achieve the recreational goal. (One success measure in the BC Freshwater Fisheries Program is that species at risk listing decisions decline as recovery plans achieve positive outcomes.) Thus this management goal aims to maintain wild populations’ integrity and at abundance levels that will not only prevent this species from becoming more at-risk but allow this species to be considered not-at-risk by COSEWIC.
Available data provide some information on genetic integrity, abundance, habitat conditions, and angling characteristics; however, at this time species/population specific targets relating to genetic integrity and abundance to meet conservation and recreation objectives cannot be quantified. A prioritized list of recommended actions along with the necessary indicators, measures, and proposed targets to meet objectives are provided in this plan. Since the COSEWIC assessment in 2006, some trend data have been collected for several rivers that show increasing abundance trends and populations over proposed abundance targets. However, the major threat of genetic introgression appears to be increasing.
6. Management objectives
The following are the management objectives:
- maintain the native distribution and genetic diversity of populations;
- maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits;
- maintain, or rehabilitate, the capacity of natural habitat to meet abundance targets for populations; and
- optimize sustainable recreational benefits.
6.1 Summary of indicators, measures, and targets, and status of management objectives
Table 2 summarizes these management objectives and associated suites of indicators, measures, and targets considered appropriate to track our success in meeting objectives for WCT as well as the status of meeting these targets. Justifications for the selection of these targets follow in Section 6.2. Details on the status of meeting these targets as they relate to the suite of indicators are provided in Sections 7.1–7.4.
Long Description for Table 2
Table 2 is titled “Summary of available indicators, measures, targets, and status of meeting targets for each management objective.” The table is read horizontally from left to right, and consists of five columns and five rows. The top row contains the column headings: Objective, Indicator, Measure, Target, and Status - Meeting target? A footnote on the column titled “Target,” and on the word “populations” in row two, column two offer further explanations.
|Objective||Indicator||Measure||Targeti||Status - Meeting target?|
|1. Maintain the native distribution and genetic diversity of populations||Distribution||Proportion of native range occupied||Presence in a minimum of 80% of historic native range||YES - assumed, but does not consider genetic integrity|
|Genetic integrity||Introgression||< 10% of each population group are introgressed at levels > 1%||NO - based on limited survey work|
|2. Maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits||Abundance in wild populationsj||Total adult abundance by population||Minimum of 80% of populations at adult abundance levels > 0.4 Nequilibrium||UNKNOWN - no appropriate metrics available|
|Angling mortality||Mortality related to catch and release angling before maturity in exploited populations||< 5% catch and release related mortality in exploited populations||UNKNOWN - significance of catch and release and harvest mortality unknown|
|3. Maintain, or rehabilitate, the capacity of natural habitat to meet abundance targets for populations||Riparian habitat||Total stream length with undisturbed and wind-firm riparian buffers||A high proportion of stream length is undisturbed||UNKNOWN - needs detailed watershed level assessment|
|Water availability||Proportion of streams meeting or exceeding minimum flow needs||A high proportion (~80%) of streams meet minimum flow requirements||VARIED - depending on Population Group but some info missing|
|Road density||Road density by watershed area (km/km²)||Road density by watershed area is 0.4 km/km² or less||NO - in all Population Groups, target exceeded but more in-depth analysis required|
|Habitat access||Abundance of human-made stream crossings believed to create fish passage problems||Reduced number and severity of barriers (relative to current baseline)||NO – at level of assessment considered, but could use more detailed information|
|Water quality||Deleterious substances||WCT streams meeting/exceeding Water Quality guidelines for deleterious substances||VARIED - depends on criterion being measured, needs more info|
|4. Optimize sustainable recreational benefits||Fishing quality||Proportion of anglers rating fishing experience as “good” or “excellent”||Crowding index as negotiated in current angling management plan (B.C. Ministry of Environment 2006)||PROBABLY - but metrics need review|
|Effort||Catch per unit effort (CPUE)||River specific (e.g., 1–1.4 fish per rod-hour)||YES - in Classified Waters considered, but not particularly defensible|
|Fish size||Length||More large fish||YES - in the few Classified Waters systems considered|
|Harvest||Availability of harvestable fish||Sustainable harvest is maintained||UKNOWN - opportunities persist, but biologically defensible thresholds unknown|
|Angling regulation compliance||Proportion of anglers in compliance with regulations||< 10% non-compliance||NO – exceeded for Classified Waters, unknown elsewhere|
|Valuation||License sales||Increase in valuations associated with the fishery||UNKNOWN - analysis not conducted|
i Unless explicitly stated, target applies to Population Group level (see Section 4.2.2).
j Should consider exploited and unexploited (i.e., headwater), isolated populations separately.
6.2 Targets and justifications for management objectives
Objective 1. Maintain the native distribution and genetic diversity of populations
- Self-sustaining wild populations occur in a minimum of 80% of each population group’s historic native range.
- Less than 10% of all populations are introgressed at levels > 1%.6
The long-term persistence of a species depends on the spatial distribution of populations,7 their genetic composition, the movement of individuals among populations, and the physical and biological factors within their immediate environments that influence population abundances. Implicit in the distribution target is that genetic and phenotypic (i.e., life history) diversity are retained. We assume that for the most part the current range approximates the historic, post-glacial native range except in cases where obvious habitat losses have occurred (e.g., migration barriers, lake conversion to tailings pond), but this can be informed with further investigation similar to Prince (2001), and gathering of aboriginal traditional knowledge (ATK). A target of 80% occupancy is somewhat arbitrary but represents a reasonable interim target for this objective, particularly as the historic distribution cannot be determined with certainty, and should avoid a declining distribution, which could contribute to a COSEWIC at-risk assessment (COSEWIC 2010).
The degree to which populations are physically connected influences gene flow (i.e., via exchange or migration of individuals) among populations. When physical connectivity is reduced or eliminated, populations may become fragmented into small, genetically and physically isolated subpopulations that are more vulnerable to local extinction through stochastic events (due to reduced or no recolonization potential) and inbreeding. Loss of migratory life history types will also result, further eroding resistance to extinction. On the other hand, increasing physical connectivity beyond what naturally occurs is not necessarily beneficial as it can result in increased levels of migration and gene flow among populations, resulting in the loss of local adaptive traits (including co-evolved gene complexes) and, in some cases, increased hybrid presence. Life history variability maintains adaptive options under different environmental conditions to increase the likelihood of survival within population and as a species, allowing higher exploitation of different niches and contributing to spatial diversity.
Current hatchery programs do not contribute to this objective (i.e., they primarily support objective 4). In fact, hatchery practices can create challenges to achieving Objective 1 in some situations, and hybridization and competition with invasive fish species were the foremost reasons for the recent COSEWIC assessment and SARA designation of Special Concern. To maintain the genetic integrity and associated unique characteristics associated with distinct populations within the species (including species-specific behaviour adapted to the extreme conditions they may be exposed to), protecting wild, non-introgressed WCT is of the upmost importance. Those populations containing significant levels (i.e., > 1%) of introgression with other salmonid species may pose a threat to pure populations (where inter-breeding is possible) although they may be of some conservation value under a scenario where no or few pure populations remain. In particular, WCT appear to be particularly vulnerable to introgression with Rainbow Trout in watersheds outside of the native range of Rainbow Trout where the two species have not co-evolved or developed mechanisms to minimize inter-breeding. The maintenance of genetically pure WCT populations is not just a philosophical argument; hybridization between WCT and non-native trout can result in outbreeding depression and the loss of co-adapted gene complexes, leading to the loss of local adaptations (Barton and Hewitt 1989). A recent study indicates that even low levels of hybridization between WCT and Rainbow Trout that are only detectable via genetic testing (i.e., no morphological differences apparent) can result in markedly reduced reproductive success; at 20% admixture, there was a 50% decrease in reproductive success (Muhlfeld et al. 2009). This study suggests that protecting populations with even low levels of admixture could facilitate further expansion of hybridization. Hybridization also interferes with homing behaviour and increases straying rates, further homogenizing populations (Boyer et al. 2008).
Objective 2. Maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits
- 80% of exploited wild populations in each population group are at adult abundance levels greater than 0.4·Nequilibrium8 averaged over a one-generation time interval where one generation is about 10 years.
- 80% of unexploited isolated headwater populations persist at adult abundance levels greater than 0.4·Nequilibrium.9
- Angling mortality of exploited populations is < 5% before maturity.
Indicators associated with abundance enable fisheries managers to: (1) evaluate the capacity of the particular system to support fisheries and thus the ability to establish targets; and (2) track trends in conservation status to report out to the public and to assist with setting regulations. We propose to manage WCT populations using an abundance-based precautionary management framework in which a series of abundance thresholds and control rules guide changes in management actions. These actions are designed to maintain a population (and population group) at or near a desired target abundance level that can provide sustainable societal benefits with little risk of severe population decline and associated at-risk conservation determinations (COSEWIC, SARA, or British Columbia Red or Blue list). The framework uses three abundance thresholds to define abundance ranges within which management objectives and management actions differ. Stock assessment standards and tools will be required to evaluate the status of populations from the perspective of the targets described above. Refer to Appendix 2 for a detailed description outlining the framework and derivation of abundance targets.
Mortality is also a useful indicator as it helps explain the mechanism of decline; this, of course, assumes that we can control fishing mortality. Two types of mortality may be associated with WCT fisheries: hooking mortality associated with catch and release zones, and harvest mortality.
Objective 3. Maintain, or rehabilitate, the capacity of natural habitat to meet abundance targets for populations
- A high proportion of stream length has undisturbed and wind-firm riparian buffers.
- A high proportion of streams meets minimum flow requirements.
- Road density by watershed area is 0.4 km/km² or less.10
- The number and severity of human-made barriers to fish movement such as culverts and dewatering events decreases significantly.
- WCT streams meet B.C. Water Quality Guidelines for key deleterious substances.
The quantitative relationships between both local and landscape-scale habitat characteristics and the capacity of stream ecosystems to maintain productive populations of WCT are uncertain, although the qualitative linkages are well known. The interim targets listed above are based on professional judgment and relate to the general health of aquatic ecosystems, with WCT being a focal element of those ecosystems. The interim targets may be modified by the requirements of higher-level regional land and resource use plans or by improved information. These objectives should all apply at the defined Population Group level (defined in next section).
The general intent of this objective is to maintain the productive capacity of relatively undisturbed streams to produce WCT by ensuring suitable habitat is maintained and accessible (i.e., not fragmented), supported by adequate water flows and water quality (e.g., selenium is maintained below recommended levels). There may also be limited opportunities available to increase the productive capacity of degraded streams. The B.C Ministry of Environment provides relevant water quality guidelines (criteria) and waterbody specific objectives (B.C Ministry of Environment 2013).
Objective 4. Optimize sustainable recreational benefits11
- Current angling quality standards12 established in the Angling Management Plan for Kootenay Quality Waters (B.C. Ministry of Environment 2006) are maintained or improved for crowding index.
- Catch is stable or improving.
- Average fish size for Classified Waters is stable or increasing.
- Harvest opportunities are maintained where sustainable.
- Non-compliance with angling regulations on Classified Waters is < 10%.
- Valuations associated with the fishery increase.
This management plan defers to the fishing quality targets negotiated in the East Kootenay Angling Management Plan (B.C. Ministry of Environment 2006) for the seven rivers identified as East Kootenay Quality Waters. These include legally mandated caps on total angler days, as well as guided angler days and guide allocations, mainly in response to overcrowding concerns.
We consider a number of factors indicative of our ability to optimize recreational opportunities that are considered sustainable. Once conservation objectives are met, we intend to maintain angling quality and client satisfaction, as well a diversity of recreational opportunities. Fishing quality is also a function of compliance. Efforts to increase valuation of the fishery should not only focus on increasing license sales but also on increasing public appreciation of the resource and support of management decisions.
7. Status of meeting management objectives
The following section describe the status of meeting the management objectives as they relate to the suite of indicators identified in Table 2 for WCT based on whether the targets are being met. Discussion is limited to a brief overview of information available, status (to the extent possible based on available data), and information gaps (refer to appendices for more detailed information). See Recommended Management Actions and Priorities (Section 9.3) as to the priorities and extent to which these knowledge gaps will be addressed.
7.1 Objective 1. Maintain the native distribution and genetic diversity of populations
Overview – The native range of WCT in B.C. is concentrated along the western slope of the Rocky Mountains, but limited to the southeastern portion of the province (McPhail 2007). At present, the data determining the extent to which WCT still occupy their original native range within B.C. are limited to the observations captured in the provincial FISS (Fisheries Information Summary System) database and population-specific studies where they occur.
Status – The current status of WCT in B.C. is thought to persist throughout their historical range in all major watersheds of core and peripheral areas in B.C. However, this status is complicated by two main factors:
- The extensive stocking history of WCT in the province makes it difficult to determine whether some occurrences represent historical distribution or introductions particularly in the peripheral range; and
- Hybridization with introduced, non-native Rainbow Trout has been documented in B.C. and will reduce the distribution of WCT populations that are still genetically pure (see Section 7.1.2 Genetic Integrity). The extent to which this reduction has occurred, and will continue to occur, is difficult to quantify given limited genetic analyses. However, preliminary modeling suggests that reductions may continue as long as a source of RBT is available and can access WCT populations (Bennett 2007).
Information gaps – The biggest information gap at this broad level is the lack of clarity as to the extent to which native range has been reduced by hybridization leading to introgression and the loss of genetically pure WCT populations. The section on Genetic Integrity (Section 7.1.2) addresses this to some extent, but given the limited screening of populations (N = 88 waterbodies) and lack of consistent molecular markers applied, some spatial gaps in information exist. It would be valuable to identify genetically pure populations for conservation prioritization purposes. Another uncertainty is the extent to which populations in the peripheral range can be considered viable.
7.1.2 Genetic integrity
Overview–While hybrid assessments of WCT populations in B.C. have not been extensive, they provide some indication of how significant the problem might be and suggest “hot spots” for further spread of hybridization. The main sources of molecular genetic data are provided by Bennett (2007), Muhlfeld (unpublished data), Boyer et al. (2008), and Parks Canada (Shelley Humphries, unpublished data). For more detail, refer to Appendix 4, Introgression.
Status – A total of 114 sites representing 88 waterbodies (both streams and lakes) were assessed for hybrid presence (Figure 3). What is immediately obvious is the extensive degree of hybridization occurring in two of the four central Population Groups, namely the Elk and Upper Kootenay Population Groups. In particular, it appears that any WCT-inhabited waters accessible from the Kookanusa Reservoir (i.e., in the lower portions of tributaries below barriers) contain significant levels of Rainbow Trout genes. Three additional “hotspots” for hybrids include (1) lower and mid-sections of tributaries in the lower Elk River above Elko Dam (i.e., Michel Creek area); (2) streams (e.g., White River) near Whiteswan Lake in the Upper Kootenay group; and (3), to a slightly lesser degree, upstream tributaries of Kootenay National Park in the Upper Kootenay group.
For planning purposes, note that the level of hybridization is not static and may require different management responses depending on the rate and direction of hybridization. The Kookanusa Reservoir appears to have an established Rainbow Trout population, providing an ongoing source of Rainbow Trout genes. The result is ongoing upstream movement of Rainbow Trout genes, likely associated with higher straying rates of hybrids. Without eliminating the Rainbow Trout source, expansion is expected to continue. At Whiteswan Lake, Rainbow Trout have successfully evaded containment in the lake, with spawning rainbow WCT hybrids found downstream (Heidt 2007, 2009). In contrast, there is no naturalized Rainbow Trout population associated with Michel Creek area and movement of Rainbow Trout genes is primarily downstream. Rainbow Trout genes are expected to become increasingly diluted in time and there is evidence that F1s and F2s are decreasing with pure WCT numbers not declining (P. Corbett, pers. comm., 2010). Kootenay National Park has a few hybrid populations but very few pure Rainbow Trout sources. In contrast, Yoho National Park has well-established Rainbow Trout populations in several lakes with no WCT evident.
The Canadian portion of the Flathead group appears to remain a stronghold for pure WCT; however, south of the international border, hybridized populations are scattered throughout the lower portions of the Flathead River and its tributaries (Boyer et al. 2008). It is not clear if some environmental factors (e.g., temperature) prevent further northward spread of hybrids into the B.C. portion (as there are no obvious physical barriers) or if it is a matter of time before this occurs. Survey work has been too limited to draw conclusions about the status of peripheral Population Groups.
In conclusion, for the central Population Groups where WCT distribution is concentrated, only the Flathead was within target of 10% hybrid populations; Elk and Upper Kootenay both exceeded this value significantly (for stream counts, refer to Table A5.1 in Appendix 5, Abundance). Across all sites considered (N = -113 in 88 waterbodies), only 61.4% contained pure WCT populations.
Information gaps – Only a small portion of all WCT-containing watersheds have been evaluated for the presence of hybrids; whether this is representative of the issue throughout B.C. is unknown. Particularly in peripheral range, it is not clear if the absence of hybrids is an artifact of limited sampling or truly reflects the current status. A proper hybrid assessment would require the application of a standard set of appropriate molecular genetic markers across B.C. (E. Taylor, pers. comm., 2010); this has not been done.
Figure 3. Distribution of hybridized WCT populations in southeast B.C. watersheds.
Note that percent values indicate percent WCT genotypes present. RBT = only Rainbow Trout observed, no WCT. Other genotypes include hybrids (F1s, F2s), backcrosses, and unknowns.
Long Description for Figure 3
Figure 3 is titled “Distribution of hybridized WCT populations in southeast B.C. watersheds.” The map depicts the distribution of hybridized WCT purity using seven different coloured points (dark green points represent >98% WCT; light green points represent 95 – 98% WCT; yellow points represent 90 – 94% WCT; orange points represent 80 – 89% WCT; light red points represent 50 –79% WCT; dark red points represent <50% WCT; and black points represent RBT (Rainbow Trout only). Note that percent values indicate percent WCT genotypes present. RBT = only Rainbow Trout observed, no WCT. Other genotypes include hybrids (F1s, F2s), backcrosses, and unknowns. The border of each Population Group’s range is outlined by light grey lines. Water bodies are depicted with light blue colouration, cities are depicted by black text labels.
7.2 Objective 2. Maintain wild populations at abundance levels that prevent at-risk status assessment so that the populations can provide sustainable societal benefits
7.2.1 Abundance in wild populations
Overview – Information on population abundance is extremely limited for WCT in B.C. Some short-term monitoring has been undertaken in the East Kootenays in an attempt to estimate abundance in some high priority streams. However, these values cannot be compared against a target value; at best, they may be useful to monitor trends with no established reference points.
Status – Abundance and density data have been collected for a very few high priority WCT streams in the Upper Kootenay and Elk Population Groups including the Elk mainstem, Wigwam, Michel, St. Mary, and Bull rivers. Estimates tend to reflect higher abundance and densities in the warmer, more productive sections of the rivers, and the presence of large fish in all cases, but it is difficult to evaluate the status of these populations. If we assume that 45 fish > 30 cm/km (from systems that are almost entirely catch and release; Hagen and Baxter 2009) approximates the unfished equilibrium abundance Nequilibrium for large productive systems, application of 0.4Nequilibrium as the target for large productive systems results in a numerical target of about 18 fish > 30 cm/km in fished populations. In 2008 and 2010 surveys, Michel Creek, Elk, Upper Bull, Wigwam, and lower St. Mary rivers exceeded this target; White River did not. However, we would expect if catch and release resulted in insignificant mortality then the fish densities observed should represent Nequilibrium, thus estimates in these systems should actually be for Nequilibrium. Clearly, this requires resolution. For more detail, refer to Appendix 5, Abundance.
Trend data are available for only two rivers, the Wigwam and St. Mary. These trends are mostly linked with changes in regulations with a general improvement in catch per unit effort (CPUE) since the implementation of more conservative regulations. Similarly, the increased presence of large fish in recent years indicates a positive response to more conservative regulations. No studies have attempted to determine minimum or target abundance or density values. Furthermore, headwater fluvial populations have not been assessed at all. For more detail, refer to Appendix 5, Abundance.
Information gaps – There are no metrics of abundance for WCT that consider a target, only scattered surveys of adults from a few priority WCT systems that are not calibrated against the carrying capacity of the system. It is not clear if these locations are representative of the situation throughout the WCT range. The application of a single target across a broad range of habitats where capacities could vary to some degree may also not be appropriate. Estimates of abundance are difficult and costly to generate; given this, we need to determine if we should focus on estimators of abundance (e.g., fish per kilometre) or on an alternative option like mortality (i.e., catch and release related mortality) to assess impact of fishery on abundance (see Angling Mortality, next section).
7.2.2 Angling mortality
Overview – WCT are highly vulnerable to overexploitation. Regulations for WCT in the East Kootenays have become increasingly restrictive in response to reduced CPUEs in the early 1990s with a strong positive response in CPUEs. Post-hooking mortality for catch and release WCT fisheries on Classified Waters is assumed to be 5–10% but this remains to be rigorously tested (Heidt 2010). Some concerns for fish survival have been expressed where catch and release regulations are in place, as well as for incidental catch in winter fisheries.
Status – Angling pressure is increasing in a number of Classified Waters (Tepper 2008b). Heidt (2003) estimated that 92,635 WCT had been angled from Sparwood to Elko in the Elk River in 2002; undoubtedly, many of these fish represent recaptured fish. Even with relatively low angling mortality rate (typically 3–5% estimated per capture) and apparent high catch and release rate (99.8%; Heidt 2003), injury and mortality from catch and release angling could be significant (26–94% of WCT > 400 mm long observed to have injuries consistent with hooking; see Appendix 6), on the total number of fish captured within one season or across multiple seasons. Recent snorkel surveys have also documented increasing frequency of angling-related injuries as fish get bigger; mortality may also be increasing as stream size decreases and fish vulnerability increases (Hagen and Baxter 2009). In addition, WCT in overwintering habitats are highly vulnerable, and an increase in WCT numbers has been observed recently during winter fisheries (Heidt, unpublished data). Angler surveys in 2009 and 2010 during these fisheries suggest that most anglers are targeting Bull Trout even though up to 55% of catch was composed of WCT (Heidt, unpublished data). For more detail, refer to Appendix 6, Angling mortality.
Information gaps– It is unclear how significant angling-related mortalities are for WCT persistence at the population level. The current angling restrictions for WCT are considered conservative but are mainly to provide angler satisfaction rather than meet abundance targets although conservation needs still are assumed to be met. The following questions remain: (1) Is catch and release related mortality too high in streams where fish are recaptured numerous times within a season? (2) Are there other factors like temperature that may increase mortality rates beyond an acceptable level? (3) What are the best options to reduce mortality? (4) While river fisheries appear to be 99% catch and release in Classified Waters even where harvest is permitted, how much mortality do these same adfluvial populations endure during winter bait fisheries where harvest is permitted? Given that harvest is still important to some anglers (i.e., mandatory catch and release throughout the region is not a palatable option), it is important to understand the significance of harvest rates.
7.3 Objective 3. Maintain, or rehabilitate, the capacity of natural habitat to meet abundance targets for populations
7.3.1 Riparian habitat
Overview – A number of land use activities have the potential to degrade riparian habitat buffers within the range of WCT populations including mining, urban development, agriculture, and forestry, as well as roads and railways (Oliver 2009). The challenge is to evaluate the extent to which existing and past activities have altered these habitats. Ideally, each WCT watershed would be examined to determine how much riparian habitat remains intact; this would be a hugely onerous task and not currently possible although application of remote tools (e.g., satellite imagery) may be of assistance. Available information to evaluate this indicator is very limited.
Status – No particular activity has had wide-ranging impacts to riparian habitats within the WCT range in B.C. Cumulatively, the combined alterations associated with forestry, agriculture, road and rail crossings, mining, and urban development have undoubtedly compromised the riparian buffers for some smaller WCT streams particularly in the upper Columbia, Elk, and Upper Kootenay (southern portion) Population Groups. The extent to which this has occurred is not available. For sector-by-sector breakdown, refer to Appendix 7, Riparian habitat buffers.
Information gaps – Without a detailed watershed-level analysis of land use and associated impacts to riparian habitats, it is impossible to quantify the amount of intact riparian habitat by stream length. In particular, sensitivities to forestry have only been conducted for a fraction of the watersheds within WCT range, and it is not clear to what extent cattle are able to access streams, particularly in smaller streams. Furthermore, there appears to be some question as to whether there are ongoing riparian impacts associated with forestry, or if the impacts are largely residual based on impacts to small streams that occurred before the Forest Practices Code, which was enabled in 1996.
7.3.2 Water availability
Overview – A recent analysis of natural flow sensitivity was conducted at the ecosection level, which included the range of WCT in B.C. (Ptolemy 2010). This assessment used water gauge data from specific streams within the region to calculate percent mean annual discharge at various times of the year. Results were then used to characterize each ecosection for natural flow sensitivity. For more detail, refer to Appendix 8, Natural flow conditions.
Status – WCT streams within the key range with potential flow sensitivity concerns are concentrated in the Southern Rocky Mountain Trench (i.e., the southern portion of the Upper Kootenay Population Group), and particularly for the East Kootenay Trench and McGillivary Range ecosections (Ptolemy 2010). Lowest baseflows actually occur during winter months, affecting winter survivorship of WCT. Outside of this key range, similar concerns also exist for tributaries of the lower Columbia and lower Kootenay rivers, as well as Kettle River (see Figure 4).
The Flathead and Elk Population Groups are generally not susceptible to drought conditions, similar to the upper portion of the Upper Kootenay Population Group, which occurs in the Rocky Mountains and receives adequate flows in general. In terms of meeting the interim target of 80% of streams meeting minimum flows, information is limited to the streams that are monitored. Specific failures to provide adequate fish flows have been reported for two creeks (Wolfe and Joseph creeks). Refer to Threats Assessment (Section 8.3) on water use for more details.
Information gaps – Minimum fish flow needs for WCT will vary according to stream and season. In particular, spawning, rearing/overwintering, and passage requirements will undoubtedly differ; these have yet to be defined for WCT. Another remaining gap is the analysis of existing baseflow data on a stream-specific basis in terms of current water allocation (R. Ptolemy, pers. comm., 2010). Natural baseflows may already be below minimum fish flow needs in some cases. Finally, the relationship between groundwater and surface flows remains unknown.
Figure 4. Landscape-level assessment of flow sensitivity in different ecosections within assessed ecosections within the native range of WCT in B.C.
Long Description for Figure 4
Figure 4 is titled “Landscape-level assessment of flow sensitivity in different ecosections within assessed ecosections within the native range of WCT in B.C.” The map depicts flow-sensitive ecosections using light red shading, and not flow-sensitive ecosections using light green shading. The border of each Population Group’s range is outlined by orange lines. Water bodies are depicted with light blue colouration, cities are depicted by square grey points, and hydrometric stations are depicted with red stars. A scale is provided in the lower right corner. An inset map shows the general location of Westslope Cutthroat Trout distribution relative to: the rest of British Columbia, the British Columbia-Alberta border, and the British Columbia-Washington State border.
7.3.3 Road density
Overview – Roads have been identified since road density has been negatively related to Pacific salmon (Bradford and Irvine 2000) and WCT abundance (Valdal and Quinn 2010). Road data are currently available in two databases: the digital road atlas, which includes most road developments in the province and most forestry roads; and the forestry roads, both available in the Land and Resource Data Warehouse (LRDW). As the digital road atlas provides a more complete coverage of all roads (though some forestry roads are not connected), a road density analysis was limited to these data.
Status – Based on a target value of 0.4 km/km² (Stalberg et al. 2009), every Population Group exceeds the target significantly, suggesting even at this very broad level that we might expect to see a higher risk of negative effects to habitat (Table 3). The distribution of roads within the various groups will undoubtedly depend to some degree on topography, as well as development.
Long Description for Table 3
Table 3 is titled “Summary of road density by Population Group.” The table is read horizontally from left to right, and consists of four columns and eight rows. The top row contains the column headings: Watershed group area (km2), Road length (km), and Road density (km/km2). Footnote “a” reads as follows: Analysis provided by Byron Woods. Footnote “b” reads as follows: Road data were derived from provincial digital road atlas (WHSE_BASEMAPPING.DRA_DIGITAL_ROAD_ATLAS_LINE_SP).
|Population Group||Watershed group area (km²)||Road length (km)||Road density (km/km²)|
a Analysis provided by Byron Woods.
b Road data were derived from provincial digital road atlas
Information gaps – This analysis was conducted at a very broad scale considering groups of watersheds rather than individual (e.g., third-order) watersheds. A more detailed watershed-by-watershed assessment may better focus where the greatest risks occur. This also does not consider where in the watershed WCT are distributed or the types of roads (paved, unpaved) involved.
7.3.4 Habitat access
Overview – Natural migration corridors enable WCT populations to access a breadth of habitats necessary to support the various life stages although migratory distances will vary according to life history type and habitat availability (Appendix 9, Site fidelity). Loss of connectivity reduces resilience in several ways: it increases threat of extinction associated with stochastic events; it prevents natural recolonization should local extirpation occur; it results in the loss of life history variation (i.e., only headwater fluvial populations persist); and it increases small-population issues like inbreeding and loss of variability. The number of stream crossings within each WCT Population Group is staggering; however, these crossings vary greatly in form (open-bottom structure to small enclosed culvert), which will influence their ability to pass fish (Figure 5). The actual number of crossings that have been assessed from a fish passage perspective is limited to less than 5% (C. Mount, pers. comm., 2011).
Status – Relative to populations in other jurisdictions (e.g., Shepard et al. 1997), some studies suggest that WCT in B.C. have experienced much less habitat fragmentation and destruction at a broad level. For the most part, they continue to persist as interconnected populations throughout much of their core range in the Upper Kootenay drainage (Hagen and Baxter 2009). This is probably the case for Flathead and Elk populations as well. In fact, a radio-tagging study conducted in the Elk River demonstrated that large adult WCT (i.e., FL > 330 mm) are able to ascend barriers 2 m high (e.g., cascade falls, beaver dams) under low and high water conditions (Westslope Fisheries Ltd. 2003). Clearly, numerous major hydro-electric dam developments on the Columbia, Lower Kootenay, and Pend d’Oreille mainstems have altered the degree to which tributaries can maintain connectivity. However, at least in the Columbia Population Group, it is not clear how broadly distributed WCT may have been before the dams. These rivers all contain native populations of Rainbow Trout. It is possible that the WCT in these regions may already have been naturally restricted to colder headwater tributaries as Rainbow Trout recolonized mainstems and lower, warm sections of tributaries.
That being said, a recent GIS-based modeling exercise (see Appendix 10, Stream crossings) estimated that a total of 69,131 stream crossings associated with forestry roads occured within the WCT range, of which about two-thirds (42,483) of these are modelled to be on fish habitat (C. Mount, unpublished data). A total of 2017 (< 5%) of these crossings have been assessed on the ground for fish passage problems (excludes Flathead and Elk Population Groups where no assessments have been conducted), about half of which are closed-bottom structures that are more likely to be barriers than open-bottom structures (C. Mount, pers. comm., 2011). Closed-bottom structures in the form of round culverts had significantly higher rates of failure, approaching or surpassing 50% in all Population Groups in which they were assessed. For the most part, all other structures had 0% failure rates to provide passage. Although this analysis needs further resolution in terms of its representation of the overall issue, it does suggest that stream crossing associated with culverts could represent a signficant problem for migratory populations.
Information gaps – This recent analysis is the first of its kind to undertake a landscape-level assessment of barriers to fish movement for WCT. The results should be unbiased in terms of representation (C. Mount, pers. comm., 2011). Thus, extrapolation of the results suggests that barriers associated with road crossings may be a much larger habitat threat than previously known. A key next step would be a more detailed GIS-based analysis to determine highest priority barriers where removal would enable access to significant lengths of stream. As mentioned, this analysis was limited to forestry road crossings. It is impossible to gauge the extent to which fish passage associated with road and rail crossings is a concern for the various Population Groups. However, this issue should be investigated particularly along the floodplains of the Elk, Kootenay, and Columbia rivers (Oliver 2009).
Figure 5. Known stream crossings based on intercept analysis of road/rail x stream, within the WCT range in B.C. Crossings differentiated according to stream sections identified as fish-bearing or non-fish-bearing.
Long Description for Figure 5
Figure 5 is titled “Known stream crossings based on intercept analysis of road/rail x stream, within the WCT range in B.C. Crossings are differentiated according to stream sections identified as fish-bearing or non-fish-bearing.” The map depicts fish habitat road crossings using red points, and non-fish habitat using purple points. The border of each Population Group’s range is outlined by green lines. Water bodies are depicted with light blue colouration, cities are depicted by square grey points, and ecoregions are depicted with varying shades of grey, brown, or yellow. A scale is provided in the lower right corner. An inset map shows the general location of Westslope Cutthroat Trout distribution relative to: the rest of British Columbia, the British Columbia-Alberta border, and the British Columbia-Washington State border.
7.3.5 Water quality
Overview – Coal mining, urban runoff, and agriculture are associated with elevated levels of several chemical contaminants including selenium, calcite, and nitrogen. Some chemicals related to nutrient loading may be considered either positive or negative depending on the system; however, others are considered deleterious substances.
Status– Michel Creek drainage actually appears to have benefited from elevated levels of nitrogen in combination with naturally high background concentrations of phosphorus; increased benthic productivity has improved food resources for foraging WCT, which has downstream effects on WCT in the mainstem Elk River as well (Oliver 2009).
Elevated selenium (Se) levels in Fording River associated with coal extraction continue to be a concern although a recently convened panel of experts could not agree on whether population-level effects for WCT have or will occur in the Elk Valley (Oliver 2009). Levels will continue to be monitored, but the response has been to minimize selenium input rather than trying to establish cause and effect. Finally, the deposition of leached minerals like calcite downstream of some rock drain facilities associated with coal mining in the Elk Valley represents a potential loss of fish habitat. Specifically, these minerals cement loose river bottom gravel, essentially infilling all interstitial spaces (D. Martin, pers. comm., 2011).
Information Gaps – We still do not know how great an impact selenium may have on WCT populations in the Elk River, or on fish growth, reproduction, and survival in general. The deposition of minerals resulting in the calcification of river gravel is a potentially growing concern in the Elk Valley but it is not clear how water chemistry influences the extent of depositions or the amount of fish habitat.
7.4 Objective 4. Optimize sustainable recreational benefits
7.4.1 Fishing quality
Overview – Once the conservation Objectives (#1–3) are met, there should be substantial recreational opportunities to be optimized consistent with the Fisheries Program Plan. Fishing pressure for WCT in B.C. appears to have increased significantly in recent years, partly in response to rebuilding stocks and partly due to expanding human development in the region (B.C. Ministry of Environment 2006). Guides and regional fisheries biologists have observed degradation in the quality of angling experience or expect to see it due to high fishing pressure on some streams (EKAMPC 2003; Hagen and Baxter 2009).
Status – In response to perceived or expected degradation of the angling experience, seven streams in the East Kootenay Region were designated as Classified Waters in 2005–2006 with special management regimes including: the upper Kootenay River, White River, Elk River, Wigwam River, Bull River, St. Mary River, and Skookumchuck Creek. Regulatory changes were implemented to address overcrowding concerns. Angler day quota limits were established for each Classified Water by the Angling Management Plan Committee (B.C. Ministry of Environment 2006), with quotas allocated among eligible guides. A number of other objectives and issues were identified throughout the process in a status report (B.C. Ministry of Environment 2006) but they were not implemented as part of the Angling Management Plan. Follow-up assessments were conducted by regional staff and the River Guardian program on these seven streams to evaluate quality. In summary, angling quality was considered good to excellent on 100% of these rivers but crowding appeared to be increasing in almost all cases, which may reduce quality in the future. The WCT management plan will defer to the Angling Management Plan process for all targets associated with crowding. However, as the East Kootenay Angling Management Plan is a living document, there is an opportunity to work within the process the make revisions over time. For river-specific details, refer to Appendix 11, Fishing quality.
Information gaps – Outside of the River Guardian Program, the quality of the angling experience on unclassified waters is not monitored and unknown.
Overview – A significant increase in angler days has been observed in response to improved fisheries, based on repeated creel surveys completed on selected waterbodies. Catch per unit effort (CPUE) has been used as an alternative metric of quality fisheries.
Status – Long-term CPUE trend data are available for only two WCT rivers in B.C., namely the Elk and St. Mary rivers. In both cases, historical estimates were well below the proposed target of 1.0–1.4 fish per rod-hour but recent estimates exceed this target (Table 4). CPUEs have been tracked over the past 5 years for the Bull, Michel, White (Elk), Skookumchuck, St. Mary, and Wigwam (East Kootenay) rivers. In all cases, the target is almost met or exceeded. However, for both the St. Mary and Wigwam rivers, a recent downward trend was also observed. For specific CPUEs, refer to Appendix 11, Fishing quality.
Information gaps – The proposed 1.0–1.4 fish per rod-hour target is not based on a well-defined biological reference point but rather what appears to be associated with Quality Waters rivers considered “excellent quality.” Given the variability of productivity capacity of WCT streams, even this target may be too high in some cases. The significance of angling-related mortality associated with increasing effort is unknown (see Objective 2). No CPUE information is available for unclassified rivers.
Long Description for Table 4
Table 4 is titled “Summary of WCT CPUE on Quality Waters where effort has been reported over time.” The table is read horizontally from left to right, and consists of six columns and five rows. The top row contains the column headings: River, Date, Angler effort - days (hr), Fish caught, CPUE, (fish per hour), and % WCT released.
|River||Date||Angler effort - days (hr)||Fish caught||CPUE |
(fish per hour)
|% WCT released|
|Elk River (Elko Dam to Sparwood)||1982/83 (Martin 1983) - summer/fall||6,493 (6,686)||2,824||0.37||?|
|1991 (Westover 1993) - 1.3 months||2,705||4,100||0.46||82.6|
|2002 (Heidt 2003) - 4 months||10,719 (66,025)||98,031||1.48||99.7|
|Upper St. Mary River||1979 (Martin 1984) - July/August||? (5,000)||4,000||0.71||?|
|Lower St. Mary River||1992 (Heidt 2003) - July/August||? (4,421)||?||1.7 (not extrapolated)||?|
|Upper and Lower St. Mary||2003 (Heidt 2004) – July to September||2,469 (15,233)||28,694||1.88||99.6|
7.4.3 Fish Size
Overview – Fish size has been reported in association with abundance estimates. While fish size contributes to the quality of the angling experience, it is also used as a crude estimator of population health, usually considered in connection with age structure.
Status – WCT usually recruit to the fishery at a fork length 300 mm. Oliver (2009) reported that 50% of fish captured for a tagging study in 2008 on the Elk River were > 300 mm in length. Similarly, estimates of numbers of fish exceeding 300 mm appear to have recently increased in the Wigwam River and the lower St. Mary River (although this river had historically higher estimates). However, it is not clear what quantitative targets should be set for quality fisheries. For more detail, refer to Appendix 11, Fishing quality.
Information gaps – No quantitative target is available. Established targets should be in relation to size at age and size distribution.
Overview – There is still strong support from a small sector of the recreational angling community for harvestable opportunities for WCT, once conservation goals are met.
Status – Harvest is limited to five trout per day with only one WCT over 50 cm in non-Classified Waters of the Kootenay management region. Limited harvest is permitted in some sections of Classified Waters; however, even in these sections, catch and release practices are estimated to be 99% (Heidt 2003, 2009). Harvest rate on non-Classified Waters is unknown.
Information needs – It is impossible to determine what sustainable harvest levels are for any systems because there is no information on carrying capacity.
7.4.5 Angling regulation compliance
Overview – Status data for compliance regarding licensing and other regulations have only be collected for Classified Waters.
Status – For the seven Classified Waters, the River Guardian program encountered 17% non-compliance and 24% infractions (i.e., actual number of violations, which could be more than one per angler) based on interviews with 608 anglers in the summer and fall of 2008. This is considered high compared to the benchmark of 10% used by the Conservation Officer Service as a general provincial target for anglers (Tepper 2008b). Angling license infractions appeared to increase disproportionately from 2006 to 2008 compared to other infractions, although barbed hook concerns remain high. The highest rate of infractions occurred in non-resident Canadian angler group with lowest being from the United States. The highest infraction rates occurred on the Bull, Skookumchuck, and White systems (38%, 38%, and 35%, respectively), whereas the lowest occurred on the Elk (15%). This appears to be consistent over the past 3 years monitored (2006–2008). Compliance is related to the number of people fishing on the river, and the River Guardian program plays a key role in communicating the regulations to anglers.
Information needs – There is no information regarding compliance in WCT waters outside of the Quality Waters program.
Overview – This indicator speaks to maintaining benefits associated with generating license sales, a key driver of the provincial Fisheries Program. The focus of this indicator is on Classified Waters where most revenue for WCT is generated. However, valuation should also consider the “attraction” of the fisheries experience, which is much more difficult to quantify.
Status – Based on the 2005 Fishing Survey of Canada, the total number of angler days for the Kootenay region is 645,000. Allocated guided angler days are approximately 5,000 (for all species), but the actual used days are probably only 60–70% of this (J. Burrows, pers. comm., 2011). Thus, the total percentage of angler days represented by guided angler days is about 0.62% (J. Burrows, pers. comm., 2011). How this relates to the percent of total angler days specifically on Classified Waters is unknown.
With respect to license sales for Classified Waters in the East Kootenays, an analysis of Angler Management Plan (AMP) sales targets (B.C. Ministry of Environment 2006) versus counterfoil counts in 2005–2006 indicates that sales fell short of targets for 5 of the 7 Classified Waters; however, sales exceeded targets for both Wigwam and Elk rivers (Table 5).
In terms of actually monetary value of the WCT fishery, a 2005–2006 evaluation of license sales for Classified Waters (3,363 residents; 2,444 non-resident Canadian; 5,489 non-resident alien) plus angling guide rod day fees approximated $285,000 (J. Burrows, pers. comm., 2011). However, the 2005 federal angler survey indicated that direct expenditures per day (including license and other) were about $107 per angler. For out-of-province anglers, this equates to approximately $1 million while a conservative estimate for B.C. resident anglers (5 days each at about $20 per day) equals about $300,000. Thus, a reasonable estimate for 2005–2006 is $1.5 million but this does not include non-classified waters. Given that there are 40,000 to 50,000 active anglers in the Kootenay region, many of whom undoubtedly fish for WCT, a conservative total estimate is probably more than $2 million per year for WCT (J. Burrows, pers. comm., 2011).
Anecdotal information suggests that non-resident anglers value the WCT fisheries in the Kootenays, not only for the fish but also for the full “wilderness experience.”
Information gaps – It is very difficult to identify a measurable WCT-specific metric for this objective. It is not clear to what extent this objective can be assessed quantitatively.
Long Description for Table 5
Table 5 is titled “Comparison of license counterfoils with East Kootenay Angling Management Plan targets for Kootenay (B.C. Ministry of Environment 2006; Burrows 2007).” The table is read horizontally from left to right, and consists of five columns and nine rows. The top row contains the column headings: Watershed, Unguided non-resident AMP target, Guided AMP target, Total target, 2005–2006 Counterfoils. A footnote on the column heading “Unguided non-resident AMP target” offers further explanation.
|Total target||2005–2006 Counterfoils|
|St Mary River||1500||1250||2750||941|
k AMP: Angler Management Plan.
Threats are defined as the proximate activities or processes that have caused, are causing, or may cause in the future the destruction, degradation, and/or impairment of the entity being assessed (population, species, community, or ecosystem) in the area of interest (global, national, or subnational) (Salafsky et al. 2008). For purposes of threat assessment, only present and future threats are considered.13 Threats do not include limiting factors which are presented in Section 4.3.14
Key threats to WCT are described in this section using categories found in Hatfield and Long (2010). With this approach, threat mechanism15 and threat source (i.e., what is responsible for the threat) are recorded independently as proposed by Balmford et al. (2009). Section 8.2 details the threat assessment completed for each population group.
8.1 Threat sources
The threats to WCT in B.C. associated with land use, water use, fishing, and hatchery stocking are summarized in Oliver (2009) and Costello (2007). Thus, the following is limited to a brief description of the threat sources to WCT following categories used by Hatfield and Long (2010).
8.1.1 Forest harvest
Oliver (2009) compared equivalent clearcut areas (ECAs) to evaluate potential impacts of logging and related activities on WCT. He considered 50 WCT tributaries (large and small) of the upper Kootenay and Columbia rivers, although he acknowledged that these are limited in terms of representation of entire WCT range. He concluded that although harvest effects are variable in terms of changes to peak flow, harvesting has largely occurred within acceptable levels without producing large imbalances in hydrologic stability. Sensitivities may be most evident at the micro-scale (i.e., sub-basin) where disturbance to basin area ratios are bigger. Furthermore, he summarized the outcome of a study assessing fish habitat condition downstream associated with different riparian treatments upstream (Johnston 2001). Where riparian buffers were provided, summer temperatures were not elevated. He indicates that practices have improved significantly over the past 30 years, and current operations are not perceived to be as detrimental as past practices. Impacts to riparian habitats are mostly residual based on practices before the implementation of the Forest Practices Code in 1996. The most significant impact related to forestry may be the road development and associated stream crossings (see discussion below on Linear Projects), as well as stream access for anglers. However, recent discussions indicate that some ongoing concerns persist particularly related to small WCT streams, salvage logging, ongoing sedimentation, and inadequate riparian buffers in the lower Columbia unit (C. Legebokow, pers. comm., 2010).
For the most part, mineral mines within the WCT range are small-scale operations and considered relatively benign from an environmental aspect; coal mining is by far the biggest mining concern in the region (Oliver 2009). Principal changes are physical and chemical in nature, involving fish passage, habitat loss, and water nutrification and contamination. Of particular concern in the Elk Valley is the link between coal extraction and selenium introduction into the aquatic environment. Selenium has been linked with defects in reproduction and growth, as well as mortality and deformity in WCT (summarized in Oliver 2009). However, studies in the Elk Valley have been inconclusive in terms of population-level impacts to WCT, and the issue remains unresolved. In general, potential impacts may range from localized habitat losses (e.g., rock drain construction, mine footprint) to downstream concerns associated with water quality. The Population Group with the greatest ongoing concern of these threats is in the Elk Valley, due to elevated selenium levels.
8.1.3 Linear projects
Roads may impact WCT populations in two ways: they increase access to vulnerable populations and they can interrupt fish passage at stream crossings. The issue is mainly historic in nature; new road development is sensitive to fish passage and standards have been developed to minimize impacts (Oliver 2009). However, a number of railway crossings (e.g., in the Elk Valley) that have been in place for years may be problematic. Although a few examples are known (e.g., Dalzell Creek in the Elk Valley), the extent to which crossings may impact WCT passage remains unknown. A recent analysis indicates that up to 50% or more of culverts assessed in the region would likely present a fish barrier (C. Mount, unpublished data).
Valdal and Quinn (2010) identified an additional factor, namely road density, which may be an indicator of WCT abundance although this is complicated by potentially cumulative effects of development activity type. Specifically, a significant negative relationship was observed between WCT density and cumulative effects of forestry-related activities as measured by road density, roads on erodible soils, roads within near-stream zones, and two measures of logging to the stream bank. This study considered reconnaissance level fish abundance data collected between 1996 and 2000 via electroshocking for six river basins within the upper Kootenay River. In particular, proximity of roads to streams (i.e., within 100 m of streams) was a significant factor. Furthermore, a significant correlation suggested logging of non-fish bearing perennial and ephemeral streams can be a key factor in WCT abundance downstream, whereas consideration of all stream reaches did not demonstrate a significant relationship. This may reflect the management practices associated with logging in non-fish bearing versus fish-bearing streams in B.C. Equivalent clearcut area did not appear to be a useful predictor of habitat quality, as reflected by WCT density.
Most agriculture is restricted to hay production and cattle, and follows irrigation water license distribution along the valley bottoms in the Elk, Kootenay, Upper Columbia, Slocan, Kettle, and Shuswap rivers (Figure 6; Oliver 2009). One significant issue related to agriculture within the native range of WCT is water extraction for irrigation during the summer months (Oliver 2009). As storage facilities are limited or non-existent in most cases, removal is on an as-needed basis. In particular, the smaller streams with naturally low summer base flows are most vulnerable during July and August, particularly in the dry Southern Interior Mountain Trench ecosection in which much of the Upper Kootenay Population Group occurs (Ptolemy 2010). Riparian habitat damage is another significant concern in much of the core range where cattle are able to access small (possibly important spawner) streams, leading to sedimentation and increased water temperatures. Grazing leases are extensive but impacts associated with access to small streams are more localized. Nutrient loading associated with feedlot runoff may occur in some instances. There is some suggestion that increased nutrient levels may benefit introduced Rainbow Trout populations in the Upper Kootenay area (M. Robinson, pers. comm., 2010).
8.1.5 Residential, recreational, and commercial development
Probably the best documented example of how urban development may impact WCT in B.C. is represented by Joseph Creek, a WCT stream that runs through the city of Cranbrook. This stream has suffered a multitude of impacts related to urban development including water quality degradation (reduced oxygen levels, elevated contaminants, sedimentation, nutrient loading, and increased temperatures) associated with altered runoff patterns and storm sewer inputs (Oliver 2009). Similar impacts likely occur in receiving waters of all communities within WCT range. This degradation impacts spawning habitat and fish health. Water use is also a major concern but is discussed below.
8.1.6 Water use - Permanent water withdrawal (consumptive)
This category includes domestic and irrigation water licenses (Figure 6). Removal of water associated with irrigation has been discussed in the status section to some extent already. Water use associated with storage facilities (i.e., reservoirs) has not. Joseph Creek, for example, is influenced by water storage in Phillips Reservoir in two ways: (1) discontinuity in the natural flow pattern both above and below the reservoir; and (2) delay in timing of peak flow, which affects spawning cues. In 1998, WCT spawner entry was delayed as much as one month, which probably affected egg, emergence, and winter survival of offspring in the following year (Oliver 2009). In addition, lower reaches experienced summer temperatures that exceeded published optimum juvenile cutthroat rearing temperatures, which can cause stress and reduce survival (Oliver 2009). Impacts will affect reaches downstream of community reservoir outflows.
8.1.7 Water use - Temporary diversions/dams (non-consumptive)
Numerous large- and small-scale hydro facilitates operate on rivers within the native WCT range in B.C. The large dams on the Columba River downstream of Mica Dam have influenced historic WCT distributions. Within the upper Kootenay River, dams tend to be placed on natural barriers (e.g., Elko Dam on the lower Elk River). However, the completion of the Libby Dam in 1972 and Kookanusa Reservoir likely had the greatest hydro-related impacts to WCT distribution, displacing riverine populations with the inundation of habitat (Oliver 2009). Independent Power Producer (IPP) operations tend to be fairly small due to the size and location of the streams used (upper reaches with high gradients) but may pose a threat where resident populations occur (Oliver 2009). The most vulnerable season for WCT associated with IPPs may be during overwintering if water is diverted when flows are naturally low at this time (Oliver 2009).
Figure 6 provides an overview of the number of current water licenses associated with irrigation, communities, and IPPs within the native WCT range, as well as those that are pending. Water withdrawal tends to be concentrated in the valley bottoms were agriculture and urban development are most prevalent. A current license does not necessarily indicate if and to what extent water is being extracted.
Figure 6. Overview of all current and pending water licenses within the WCT range in B.C.
Long Description for Figure 6
Figure 6 is titled “Overview of all current and pending water licenses within the WCT range B.C.” The map depicts “waterworks” licenses and applications using hollow or filled in purple points and hollow or filled in purple triangles, and “irrigation” licenses and applications using hollow or filled in red points and hollow or filled in red triangles. The border of each Population Group’s range is outlined by green lines. Water bodies are depicted with light blue colouration, cities are depicted by square grey points, and ranges and highlands are labelled with upper case letters. A scale is provided in the lower right corner. An inset map shows the general location of Westslope Cutthroat Trout distribution relative to: the rest of British Columbia, the British Columbia-Alberta border, and the British Columbia-Washington State border.
Records are largely limited to the Elk and St. Mary systems in the Kootenay River where public appeal and interest in the species are likely greatest. In the early 1980s, it became apparent that quality of fishing had decreased on the Elk River with only a small percentage of the catch being WCT, and mostly of smaller, younger age groups. This resulted in a shift in regulations in 1984. Since this time, both quality and angler use have increased significantly. The St. Mary River was virtually unfished in the 1980s because of the perception that it was highly polluted from the Sullivan Mine in Kimberly. Water quality was poor during the 1960s and 1970s, and extremely toxic conditions were noted including the complete absence of macro-invertebrate and fish communities (summarized in Oliver 2009). The mine was improved in the 1970s, and fish communities began to return. A creel survey in the 1990s indicated very high angling use of the river and excellent quality (Oliver 2009).
Angling interest continues to increase in response to the excellent quality of WCT fishing in the region. During 1991, for example, just 81 guided days were recorded on the Elk River. By 2000, that number had jumped to 1458 (COSEWIC 2006). The threat associated with angling is related to catch and release post-hooking mortality, as well as incidental catches in winter fisheries and compliance. While catch and release is considered to produce very low mortality (i.e., < 5%), the cumulative impact of multiple catch and release occurrences for individual fish may become significant throughout a summer season. For example, it is estimated that catchable trout in the Elk River may be recycled 11 times in a single season. Hooking mortality associated with a fly and lure caught fish range from 4 to 6% (Wydoski 1979). Mortality could be significantly higher, particularly associated with warm water temperatures and poor handling by some anglers. Where fishing pressure on WCT populations continues to increase, the risk associated with catch and release mortality may become a greater concern.
8.1.9 Aquaculture, hatcheries, and stocking
Several observed or potential impacts to WCT are associated with the long history of fish stocking in B.C. The three greatest impacts are:
- hybridization leading to introgression,
- competition and displacement, and
- outbreeding depression.
Refer to Appendix 12, Fish stocking, for more detail on these impacts.
Hatchery stocking records occurring within the native range of WCT in B.C. go back to the early 1900s (Table 7). Over 200 identified waterbodies within the core native range have been stocked with Rainbow Trout or WCT. Over 100 waterbodies have been stocked with Eastern Brook Trout. Finally, 20 waterbodies in the Kootenays region were stocked with Rainbow Trout and Cutthroat Trout (RBT x CT) crosses from 1929 to 1940. Most of these fish were from the Monroe “strain” produced at the Cranbrook Hatchery, but Peavine, Rosebud, and Kiakho “strains” were also used occasionally. It is unclear what subspecies of Cutthroat Trout were used in these crosses. The use of sterile strains has only been implemented fully for Eastern Brook Trout and Rainbow Trout in the past 10 years; all WCT released remain fertile and, in recent years, all originate from the Connor Lake of the upper Elk system. Clearly, many of these waterbodies were originally fishless lakes. Recent fisheries management policy requires that only lakes should be stocked, preferably those with no outlet. However, it is not clear to what extent stocked lakes can be considered isolated.
In considering waterbodies where WCT have been observed (based on FISS records), the Upper Kootenay Population Group has seen most introductions of the central groups. Only one lake and one stream received Rainbow Trout in the Flathead. Only 8 waterbodies in the Elk River reported to contain WCT received Rainbow Trout. Note that Summit Lake (in Elk group), Joseph Creek, and Bull River (both in Upper Kootenay group), which all contain native WCT populations, also directly received hatchery Rainbow Trout 10 or more times. Refer to Appendix 12, Fish stocking, for a breakdown of stocking records by waterbodies where WCT have been observed.
In summary, at least two of the main threats identified above occur to varying degrees in the Population Groups in the core WCT range in B.C. The issue of introgression has been discussed already; competition/displacement is a concern for at least one system (i.e., Joseph Creek; Oliver 2009). The potential for homogenization and outbreeding depression has not been considered. The source of WCT for stocking has a varied history. Most recently, all broodstock has come from Connor Lake but it is generally thought that Connor Lake was originally fishless. It was stocked a single time in 1950 with Kiakho Lake WCT, which in turn had been stocked with various sources of fish since 1929 including Munroe Lake, Peavine Creek, Loon Lake, and Beaver Creek. These systems themselves have been stocked. Thus, it is unlikely that the original source of Connor Lake WCT can be determined.
Long Description for Table 6
Table 6 is titled “Summary of all stocking records for WCT, Rainbow Trout (RBT), Eastern Brook Trout (EBT), and Rainbow Trout x Cutthroat Trout crosses (RBT x CT) in the core range of WCT until 2008.” The table is read horizontally from left to right, and consists of six columns and five rows. The top row contains the column headings: Species stocked, Region, Years stocked, Number of waterbodies stocked,
Frequency, Ploidy. Footnotes on the column headings “Region,” “Number of waterbodies stocked,” and “Ploidy” offer further explanation.
|Species stocked||Regionl||Years stocked||Number of waterbodies stockedm||Frequency||Ploidyn|
|WCT||4E||1923–2008||187||Up to 50+ times||Still all 2N in 2008|
|4W||1924–2007||57||Up to 50+times||Still all 2N in 2008|
|RBT||4E||1915–2008||151||Up to 100+ times||Still some 2N in 2008|
|4W||1911–2008||120||Up to 100+ times||All AF, AF3N, and 3N after 2005|
|EBT||4E||1924–2008||81||Up to 50+ times||All AF3N or 3N after 2003|
|4W||1911–1999||31||Up to 100+ times||All AF3N or 3N after 1999|
|RBT x CT||4E||1938–1949||13||1 to 2 times||All diploid|
|4W||1929–1968||8||1 to 2 times||All diploid|
l Management region 4E = Upper Kootenay (upstream of Kootenay Lake) and Flathead; 4W is Lower Kootenay and Columbia systems.
m Only those waterbodies with a unique waterbody ID number were counted. A number of records did not have any associated ID code.
n Ploidy indicates if and when some form of sterile strain was used. Ploidy levels of released hatchery fish: 2N = diploid, all fertile; 3N = triploid, all sterile, AF = all female, fertile; AF3N = all female, all sterile.
8.1.10 Climate change and severe weather
In B.C., a number of trends associated with a changing climate are relevant to WCT. B.C. Interior snowmelt systems continue to experience earlier snowmelt runoff followed by longer and drier summers (Oliver 2009). This is reflected in reduced mean annual discharge observed in southern B.C. drainages. This trend in combination with increasing water demands could be catastrophic for WCT in some small streams were naturally dry conditions already exist. A number of related impacts are associated with these low flows including: increased water temperatures; reduced oxygen levels; reduced riffle habitat; and in the winter, reduced refuge areas. Such conditions will result in increased physiological stress and mortalities.
8.2 Threats assessment
A spreadsheet-based threats assessment tool was developed for MOE to assist in identifying key threats to WCT according to mechanism and source of threat (Hatfield and Long 2010). This tool uses a ranking system similar to NatureServe (Master et al. 2009) to assess both the scope16 and severity17 of a threat to come up with a combined score for rating each threat that represents the threat impact18. The immediacy or timing19 of each threat is recorded to provide context for each threat, but it is not used in the calculation to determine the threat rating. Threats for the WCT were assessed for the entire province to identify the key provincial-level threats (see text below and Appendix 13 for details).20
The following text highlights moderate to high rated threats identified for each Population Group (Table 8), to focus attention on threats that are both understood and currently affecting populations. Descriptions list threat mechanisms21 and the sources associated with these threat mechanisms.
While the use of a threat assessment tool is valuable in identifying primary threats to species at risk, lower ranking threats, which may include wide-ranging threats and threats with significant data gaps, may play an important role in exacerbating other factors already threatening WCT, or accumulate for a larger impact. See Appendix 13 for a further description and the complete list of identified and potential threats.
- The highest ranking threats were associated with aquaculture, hatcheries, and stocking, namely:
- Introgression – associated with invasive Rainbow Trout is the highest threat.
- Altered community dynamics – is considered a medium threat associated with this source.
- Fish passage associated with linear projects is a medium threat throughout the range of the Elk Population Group.
- Two mechanisms associated explicitly with coal mining were identified:
- Riparian clearing and alteration – rock drains.
- Water quality – selenium and calcite.
- Mechanisms related to forest harvest similar to that for Upper Kootenay were identified. In particular, mountain pine beetle salvage operations were highlighted as an ongoing source of this threat.
- Altered flow regimes associated with water use (permanent withdrawal-consumptive) are considered a serious threat although localized.
A number of other lower rated and localized threats were also identified. For example, land clearing, the mechanism identified with urban development (recreational and residential), is limited mainly to the Fernie area.
No high or medium threats were identified for this population group. Historically, forestry heavily impacted this watershed, along with a major pine beetle infestation in the 1980s. However, forests appear to be recovering and WCT populations appear to be healthy. Finally, introgression downstream in the U.S. portion of the Flathead watershed should be monitored as there are no physical upstream barriers and it could spread northward.
8.2.3 Upper Kootenay
- The highest ranking threats and only non-habitat mechanisms identified were both associated with aquaculture, hatcheries, and stocking as follows:
- Introgression – Is the single greatest threat within lower sections of tributary streams accessible by Rainbow Trout from the Kookanusa Reservoir, which likely contains some level of hybridization.
- Altered community dynamics – The presence of kokanee in the Kookanusa Reservoir is thought to be influencing predation by Bull Trout on WCT. Elsewhere, Eastern Brook Trout and Rainbow Trout are thought to be displacing WCT. In Kootenay National Park, WCT in all lakes (i.e., adfluvial form) have been lost due to the introduction of Eastern Brook Trout.
- Two mechanisms related to forest harvest were identified as medium threats, and might be considered residual to some extent (i.e., cutblocks associated with practices before the Forest Practices Code implementation in 2004):
- Riparian clearing and alteration – Vegetation removal can increase peak flows and decrease summer low flows. This results in high temperatures and decreased dissolved oxygen, promoting other fish species such as invasive species. Riparian buffers are not providing a functioning riparian area. This is an ongoing issue (i.e., not just residual) as proper protection is still not occurring, especially in non-fish (first and second order) streams. However, given sufficient time substrate, distribution and invertebrate communities are recovering naturally. Salvage logging post-fire is an ongoing concern. Sedimentation may still be a concern, as is the largely deciduous forest that generally replaces lost forest.
- Water quality – considered ongoing, associated with above issue.
- Altered flow regime associated with water use (permanent withdrawals) is a medium threat – this relates to water storage (water use permanent withdrawal) on Mark and Joseph creeks.
- Linear projects were an identified source, related to the following mechanisms:
- Fish passage – the greatest threat associated with bridge and culvert crossings.
- Large-scale habitat modifications – particularly in Kootenay National Park, there has been a direct loss of habitat associated with the conversion of channel to culverts (~ 7 km).
Other points of discussion included some localized threats related to agriculture (i.e., riparian issues with cattle access to spawning streams); climate change related impacts to flow regime and water; quality; and whirling disease, which was considered a greater threat for Rainbow Trout.
8.2.4 West Kootenay
- Altered community dynamics and altered flow regimes associated with permanent water withdrawal for irrigation and consumption on private land and by communities are considered to be fairly widespread, particularly downstream of diversion and a medium threat.
- Fish passage associated with irrigation dams (water use – permanent withdrawal, consumptive) and culvert crossings for forest harvest roads on small streams (linear projects) may be a significant widespread issue, though it requires additional ground-truthing.
- Water quality, altered flow regime, and riparian clearing and alteration associated with forest harvest are threats, though may be diminishing or residual only with the onset of the Forest Practices Code.
- Instream mechanical disturbance associated with linear projects is an ongoing concern throughout this group.
- Yoho and Glacier National Parks have been considered separately from the remainder of this Population Group. As such, the greatest issues are mechanisms associated with the introduction of invasive trout species associated with aquaculture, hatcheries, and stocking as the source. In particular, both introgression and altered community dynamics have heavily impacted these areas. Outside of the parks, it is not clear to what extent these mechanisms have occurred. Road crossings that restrict fish passage are a concern but conflicting perceptions suggest more work is required to determine the extent of this threat.
- Altered flow regime associated with water use (non-consumptive – Independent Power Projects) is a significant threat throughout the tributaries of this group. Furthermore, ground water effects from IPPs are an issue and are likely to expand in the future as more projects get underway.
- Altered flow regime associated with water use (permanent withdrawal, consumptive) was also identified as a medium threat.
- Instream mechanical disturbance associated with linear projects is an ongoing threat throughout this group.
- Mechanisms related to forestry harvest are one of the most significant concerns in this group. Although mostly residual in nature, several ongoing concerns were also identified, including:
- Fish passage – associated with culvert crossings: identified as unknown in the assessment (Appendix 13), however more investigation is needed as it is thought to be a significant threat.
- Water quality – especially sedimentation.
- Riparian clearing and alteration
Hydroelectric impacts associated with the Mica area are probably not a concern for WCT because it is not known to occur in mainstem rivers in this geographic area.
There is too little information regarding the presence and distribution of WCT within the Kettle Population Group to assess threats at this time.
8.2.7 South Thompson
There is too little information regarding presence and distribution of WCT within the South Thompson Population Group to assess threats at this time.
8.3 Threat summary
Table 8 summarizes medium- to high-rated threats for each assessed Population Group. The threat with the highest threat impact is introgression associated with historic releases of reproductively capable hatchery Rainbow Trout, as well as the ongoing spread of Rainbow Trout genes associated with established Rainbow Trout populations and hybrid movement. This threat is considered ongoing, increasing in some areas, but potentially decreasing (genetic dilution) where Rainbow Trout gene source no longer exists. This threat is evident in two of the three Core Ranges for WCT: the Elk and Upper Kootenay, as well as Glacier, Yoho, and Kootenay National Parks. Related to this are the mostly residual impacts of releasing Eastern Brook Trout, particularly in the National Parks where stocked Eastern Brook Trout have replaced all adfluvial populations of WCT.
Several threats, all habitat-related, were identified as having a medium threat rating across many Population Groups. One key mechanism is altered flow regime associated with consumptive water use (irrigation, community), non-consumptive water use (IPPs), and forest harvest (riparian and water quality impacts). Fish passage, another identified mechanism, requires some significant additional ground-truthing, especially with respect to road crossings, which are confirmed to be the greatest habitat threat in the National Parks (S. Humphries, pers. comm., 2010). Mining-related mechanisms (water quality and riparian impacts) are restricted to the Elk Valley where coal mining persists.
Several threat mechanisms could be of significant concern but are currently ranked low or unknown based on lack of information. These included two key non-habitat mechanisms--harvest-related mortality, and altered community dynamics associated with introduced salmonids (in Kookanusa Reservoir) and climate change--as well as habitat mechanisms including climate change related changes to water flows and quality, and impacts of IPPs in particular on flows and passage.
While significant uncertainty is associated with threats to WCT, some general conclusions can be drawn in terms of how various threats may influence the level of conservation concern of each Population Group (Table 9). Level of conservation concern was determined by “rolling up” the factors listed in Table 9 and the key threats for each for each Population Group.
Long Description for Table 7
Table 7 is titled “Summary of medium and high rating threats for each Population Group.” The table is read horizontally from left to right, and consists of six columns and five rows. The top row contains the column headings: Threat mechanism (sub-divided into: Level 1 and Level 2), Threat source, and Threat (sub-divided into: Elk, Flathead, Upper Kootenay, West Kootenay, and Columbia). Footnotes on the column headers “Threat mechanism,” Threat source,” and “Threat,” and the term “H” throughout the table offer further explanation.
|Threat mechanismo||Threat sourceo||Threat impact by Population Groupp, q|
|Level 1||Level 2||Elk||Flathead||Upper Kootenay||West Kootenay||Columbia|
|Habitat||Altered community dynamics||Water Use – permanent withdrawal – consumptive||L||L||L||M||L|
|Habitat||Altered flow regime||Forest Harvest||L||L||L||M||L|
|Habitat||Altered flow regime||Water Use – permanent withdrawal – consumptive||M||L||M||M||M|
|Habitat||Altered flow regime||Water Use – temporary diversions/dams, non-consumptive||L||L||L||L||M|
|Habitat||Fish passage||Linear Projects||M||L||M (Hr)||M||M (Hr)|
|Habitat||Fish passage||Water Use – permanent withdrawal – consumptive||M||L||M||M||M|
|Habitat||Instream mechanical disturbance||Linear Projects||L||L||L||M||M|
|Habitat||Riparian clearing and alteration||Forest Harvest||M||L||M||M||M|
|Habitat||Riparian clearing and alteration||Mining||M||L||L||L||L|
|Habitat||Water quality||Forest Harvest||M||L||M||M||M|
|Non-Habitat||Altered community dynamics||Aquaculture, Hatcheries, and Stocking||M||L||M (Hr)||L||? r|
|Non-Habitat||Introgression||Aquaculture, Hatcheries, and Stocking||H||L||H||?||? r|
o Mechanisms and sources are based on the assessment tool described in Hatfield and Long (2010).
p Threat Impact - The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest. The impact of each threat is based on Severity and Scope rating and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. The median rate of population reduction or area decline for each combination of scope and severity corresponds to the following classes of threat impact: Very High (75% declines), High (40%), Medium (15%), and Low (3%). Unknown: used when impact cannot be determined (e.g., if values for either scope or severity are unknown); Negligible: when scope or severity is negligible.
q Note that neither Kettle nor South Thompson groups were assessed.
r High in National Parks.
Long Description for Table 8
Table 8 is titled “Summary of Population Groups with respect to trends, key threat mechanisms, and level of conservation concern.” The table is read horizontally from left to right, and consists of five columns and ten rows. The top row contains the column headings: Population Group, Area (km2), Trends (sub-divided into: Abundance, Distribution, and Habitat), Key threat mechanisms, and Level of conservation concern. Horizontal headers titled “Core” and “Peripheral” further sub-divide the rows beneath it.
|Population Group||Area (km²)||Trends||Key threat mechanisms||Level of conservation concern|
|Elk||3,565||Stable to increasing||Stable, but if genetic integrity considered, decreasing||Local losses and impacts||Introgression and altered flow regime, fish passage, water quality||High – While still considered abundant and able to support a quality fishery, significant concerns regarding introgression and localized habitat impacts exist|
|Flathead||1,579||Assumed stable||Assumed stable||Local concerns but low overall||Mechanisms related to forest harvest, introgression in U.S.||Low – Concerns relate to habitat impacts and potential introgression should U.S. fish move upstream|
|Upper Kootenay||16,566||Stable to increasing||Stable, but if genetic integrity considered, decreasing||Local losses and impacts||Introgression, altered flow regime, fish passage, water quality||High – While still considered abundant and able to support a quality fishery, significant concerns regarding introgression and localized habitat impacts exist|
High in Kootenay National Park – Introgression and culvert issues
|West Kootenay||17,563||Assumed stable but unknown||Assumed stable but unknown||Local impacts||Altered flow regime, fish passage, riparian clearing and alteration, water quality||Low-Medium – Survey information limited, introgression not apparent but populations scattered|
|Columbia||36,707||Historically more, now assumed stable but unknown||Historically more, now assumed stable but unknown||Historically more, residual forestry issues||Altered flow regime, fish passage, riparian clearing and alteration, water quality|
Introgression, altered community dynamics
|Medium – Survey information limited, introgression not apparent outside of park, but populations scattered and some habitat concerns exist|
High in Yoho– Pure WCT now limited to isolated streams, lake form lost; reverse situation in Glacier National Park – population in Schuss Lake only
|Kettle||8,165||Unknown||Unknown||Unknown||Unknown||Unknown – Status of native versus introduced WCT difficult to determine|
|South Thompson||10,483||Unknown||Unknown||Unknown||Unknown||Unknown – Status of native versus introduced WCT difficult to determine|
1 Although Objective #4 is not part of the federal Management Plan, some activities in Table 2 associated with this objective are relevant to managing Westslope Cutthroat Trout under the mandate of SARA.
2 Although Objective #4 is not part of the federal Management Plan, some Targets associated with this objective are relevant to managing Westslope Cutthroat Trout under SARA.
3 These references are cited within sections of the provincial management plan that have been omitted from the federal Management Plan.
4 The Alberta population was legally listed as Threatened under SARA in 2013.
5 Subfamily salmoninaes includes salmon, trout and char.
6 As recommended in Allendorf et al. (2004).
7 For the purpose of the management plan, a population is defined as an interbreeding, demographically similar group of individuals reproductively isolated from other such groups by time and/or space.
8 Nequilibrium has been proposed to be ≈ 45 fish > 30 cm fork length per km for large, productive streams but it is not clear if any single target can be selected given variability observed even within Classified Waters (e.g., Michel vs. St. Mary vs. Elk).
9 The goal of 0.2Nequilibrium for headwater populations was originally selected because the management goal for these stocks is assumed to be persistence rather than the ability to sustain a fishery. For small populations in situations where there are no management controls to influence the population trajectory (other than habitat protection) and natural variability may be high, it may not be realistic to define management goals as high proportions of an equilibrium abundance because we would have no effective way of increasing abundance. However, we decided that the goal should be higher because while we will not permit human-caused mortality, we will not have many options to achieve it if the population is below the target.
10 As recommended in Stalberg et al. (2009).
11 Implicit with this objective is that we have already considered First Nations traditional use requirements.
12 An average CPUE of 1.0–1.4 fish per rod-hour for Classified Waters was proposed based on observed CPUE values where fishing was considered excellent. However, these values may be too high for some systems.
13 Past threats may be recorded but are not used in the calculation of Threat Impact. Effects of past threats (if not continuing) are taken into consideration when determining long-term and/or short-term trend factors (Master et al. 2009).
14 It is important to distinguish between limiting factors and threats. Limiting factors are generally not human induced and include characteristics that make the species or ecosystem less likely to respond to recovery/conservation efforts (e.g., inbreeding depression, small population size, and genetic isolation; or likelihood of regeneration or recolonization for ecosystems).
15 The mechanism is the process– often anthropogenic – that is having (or has had) a directly negative effect on the state of the conservation target (population, species, community, or ecosystem).
16 Scope – Proportion of the species that can reasonably be expected to be affected by the threat within 10 years. Usually measured as a proportion of the species’ population in the area of interest. (Pervasive = 71–100%; Large = 31–70%; Restricted = 11–30%; Small = 1–10%; Negligible < 1%).
17 Severity – Within the scope, the level of damage to the species from the threat that can reasonably be expected to be affected by the threat within a 10-year or 3-generation timeframe. Usually measured as the degree of reduction of the species’ population. (Extreme = 71–100%; Serious = 31–70%; Moderate = 11–30%; Slight = 1–10%; Negligible < 1%; Neutral or Potential Benefit > 0%).
18 Threat impact - The degree to which a species is observed, inferred, or suspected to be directly or indirectly threatened in the area of interest (Master et al. 2009). This combined score is based on the interaction between assigned scope and severity values, and considers only present and future threats. Threat impact reflects a reduction of a species population or decline/degradation of the area of an ecosystem. (Very High; High; Medium; Low; Negligible; Unknown; Blank).
19 Timing –Timing categories are different than those provided by Master et al. (2009) and follow Hatfield and Long (2010), in an attempt to better describe trends. (Residual only, i.e., threat is no longer occurring but residual effects continue; Ongoing but diminishing; Ongoing and stable; Ongoing but increasing; and Future only (Hatfield and Long 2010).
20 Local experts were asked to individually complete a spreadsheet to rate threats. Assessment outcomes were then refined based on discussions at a provincial workshop held in December 2010. There was some concern that significant localized threats may not get highlighted. However, the purpose of this exercise was to identify the highest priority provincial-level threats.
21 Threat Mechanisms are indicated by underlined text in Sections 8.2.
- Date Modified: