| Abstract/Description or Keywords |
Teck Coal Limited (“Teck”) has commissioned a multi-year study to understand the current status of Westslope cutthroat trout in the upper Fording River watershed upstream of Josephine Falls. The title of the study is the Upper Fording River Westslope Cutthroat Trout Population Assessment – Telemetry Project (the “Project”). Westslope Fisheries Ltd. was retained by Teck to undertake the Project, under the guidance and direction of a Steering Committee. The Project is intended to provide supporting data for decision making around project planning within the upper Fording River watershed. This report is the first interim annual report (of three) with the final report anticipated in 2016. The overall goal or purpose of this population assessment study is to determine whether the upper Fording River watershed Westslope cutthroat trout population is healthy, robust and sustainable. Concerns have been raised regarding resource development and recreational use in the area and it is believed that fisheries management decisions related to the Westslope cutthroat trout population in the upper Fording River watershed would benefit from a more complete understanding of the status of the population and current habitat availability and use. To address the overall goal of the study, key study questions were identified by the Project Steering Committee, as follows: 1. What is a viable Westslope cutthroat trout population? 2. Are the fish healthy? 3. Is the Westslope cutthroat trout population sustainable? 4. Is it one interconnected population or multiple populations (with respect to genetics)? 5. What are the habitats (critical and overall habitat) in the study area? 6. What are the movement patterns and why? 7. What is the distribution of Westslope cutthroat trout seasonally, considering life-history stage and upstream distribution limits? The rationale relating to the above study questions is described in the main body of the report. Teck operates two surface coal mines within the upper Fording River watershed in southeastern British Columbia; the Fording River Operations (FRO) and the Greenhills Operations (GHO) with a total combined production capacity of approximately 14 million metric tonnes of clean coal (Mtcc) annually. Coal production began in 1971 and 1981, respectively. In addition, a third Teck surface mine, Line Creek (LCO), includes limited activities in the upper Dry Creek watershed, a tributary within the upper Fording River watershed. In addition to mining, forest harvesting, recreational activities, road, railway, and natural gas pipeline developments also occur in the upper Fording River watershed. The Fording River is a tributary to the Elk River, which is one of seven major streams and their tributaries in the upper Kootenay River watershed that were designated as Class II Classified Waters in 2005. The classified waters of British Columbia represent 42 highly productive trout streams. The classified waters licensing system was created to preserve the unique fishing opportunities provided by these waters, which contribute significantly to the province’s reputation as a world class fishing destination. In 2010, the Province of British Columbia closed the upper Fording River to angling due to uncertainty regarding population status. Westslope cutthroat trout are the only species known to occur in the upper Fording River, and its tributaries, which is defined by the portion of the watershed that is upstream of Josephine Falls. Josephine Falls represents a natural barrier to upstream fish movement and this barrier has protected this population from hybridization with non-native rainbow trout; as a result, this population is one of a limited group of populations that have been identified as genetically pure. The current research aims to characterize the fluvial population of Westslope cutthroat trout in the upper Fording River watershed in terms of abundance, condition factors, age structure, genetic differentiation, and life-history strategies. Study results are expected to identify critical habitats (e.g. over-wintering, rearing, and spawning), movement patterns and home range through the use of radio telemetry and mark-recapture techniques. It is generally recognized that four general types of threats of anthropogenic origin have led to the decline in numbers of Westslope cutthroat trout in western Canada over the past 125 years: 1. Introduction of non-native salmonids resulting in competition, replacement and hybridization. In fact, hybridization is most often considered the greatest current threat to native Westslope cutthroat trout populations; Historically, over-exploitation beginning around the turn of the century with the arrival of the Canadian Pacific Railroad; 3. More recently, habitat damage and loss; and 4. Climate change could represent a significant challenge in the future for this cold-water dependent species. Three of these four types of threats (items 1, 2 and 4 above) do not currently exist for the upper Fording River Westslope cutthroat trout population. Westslope cutthroat trout are the only species present within the upper Fording River and the population is a genetically pure population protected by a barrier (Josephine Falls), the upper Fording River watershed is currently closed to angling, and water temperatures are well within species optima. Surface coal mining and forest harvesting are the primary resource development concerns within the upper Fording River. These activities have resulted in a number of historic impacts that include; 1. Elevated concentrations of a number of metal and non-metal water quality variables notably selenium; 2. Fine sediment production (noting that Teck has comprehensive sediment control and re-vegetation plans in place to ensure compliance with water quality guidelines); 3. Habitat fragmentation and loss of groundwater influenced over-wintering habitat. The availability, quality, quantity and distribution of over-wintering habitat is frequently limited for this species and, therefore, often disproportionately important habitat for survival and recovery of Westslope cutthroat trout populations in general; 4. Fording River Road culvert crossings on Chauncey, Ewin and Dry Creeks create barriers (at least during some flows) that cut off access to these watersheds that represent a significant portion of available tributary habitat within the upper Fording River; 5. Loss of riparian habitat and spawning habitat; 6. Angling and over-exploitation may have contributed to population decreases as this population is easily accessible via Fording River Road and has been closed to angling due to uncertainties in population status; and 7. The historical use of bank armouring without current habitat mitigation techniques, thereby removing undercut banks, sweepers and log jams that provide Westslope cutthroat trout habitat. Depending on the assumptions used in the model, and the level of confidence selected, literature on Population Viability Analyses (PVA) and Recovery Potential Assessments for Westslope cutthroat trout have shown that a viable population can range between 470 and 4,600 adults. Another approach to estimating population viability has been to estimate the amount of stream required to maintain a population. Depending on the population characteristics (i.e. abundance, mortality, emigration), it has been estimated that between 9 and 28 km of stream is required to maintain an isolated population. For the purposes of this study and for consistency with the assessment end-point being used for Teck development proposals in the area (e.g., LCO Phase II and FRO Swift), the objectives for the upper Fording River population include maintaining a healthy, self-sustaining population capable of withstanding environmental change and accommodating stochastic population processes in perpetuity. In addition, there are societal aspirations for recreational use (catch-and-release angling) and harvest activities based on past use within the upper Fording River watershed. To incorporate these aspirations while maintaining long-term persistence of the population, the upper Fording River Westslope cutthroat trout population would likely need to be managed toward the higher end of these ranges. A total of 211 Floy tags were applied to Westslope cutthroat trout (size range 180 – 485 mm fork length, 80 – 1,550 g) in August-September 2012 as “marks” for the September snorkel survey (“recapture”) to facilitate population estimation using mark-recapture methods. The distribution target of four marks per kilometer was achieved for Sections S1 through S10 along the main stem of the upper Fording River (extending over 47.2 km starting at Josephine Falls) and lower Henretta Creek; but not the headwaters Section S11 or remaining tributaries of the upper Fording River. The resulting 2012 (Year 1) population estimate of 2,600 Westslope cutthroat trout greater than 200 mm over the snorkel distance of 47.6 km yields a density estimate of 55 fish/km > 200 mm and 27 fish/km > 300 mm. This preliminary population estimate is limited to fish within the main stem upper Fording River Sections S1 through S10 and lower Henretta Creek and Henretta Lake. It is recognized that additional sampling within the headwater sections and tributaries is required to confirm whether or not headwater sections and tributaries contain sub-adult and adult fish with smaller size-at-maturity. In Year 2 (2013) additional effort has been allocated to sample the headwater Section S11 of the upper Fording River and tributaries in an effort to tag and enumerate these habitats to provide a more complete population estimate for the upper Fording River. Therefore, relating back to the question of maintaining a viable, self-sustaining population, given the current population estimate (2,600 mature fish), and the available habitat (57.5 km main stem river), it appears that it is possible, if not probable, for the upper Fording River population, with suitable management strategies (e.g. habitat protection, angling restrictions), to achieve population objectives of a healthy, self-sustaining population. A key objective over the remaining two years of planned population estimates is to demonstrate the validity of the 2012 estimate through replication and to begin to understand the overall population trend (increasing, stable, decreasing). This will include fry and juvenile abundance and distribution assessments that will begin in fall 2013. Fish health was evaluated using condition factors. This included external visual examination (n=229), internal visual (surgical) examination (n=60) and comparison of size and weight-length condition factor (n=229) between the upper Fording River population of Westslope cutthroat trout and other upper Kootenay River populations sampled using similar study designs and methods (i.e. Elk, Bull, Wigwam, St. Mary Rivers). The upper Fording River population of sub-adult and adult Westslope cutthroat trout compared favourably among these populations and this was reflected in a robust Fulton’s condition factor. Only the Elk River had a higher condition factor among the populations examined. This assessment was corroborated by: a) the low incidence of deformities that were more indicative of injuries (1.7%); b) the large average and maximum fish size; and c) fish condition observations noting the absence of deformities or disease and the robust nature of the upper Fording River Westslope cutthroat trout (very thick body wall and white muscle tissue) during internal visual assessments conducted as part of the surgical radio tag implantation procedure. A review of previous genetic studies determined there was no genetic differentiation among samples taken from lower reaches of tributaries approximately 22.5 kilometers apart within the upper Fording River. This indicates there is enough “mixing” among fish with connectivity to the main stem upper Fording River to be managed as one interconnected population. Initial telemetry data for the summer and over-wintering periods supports the genetics illustrating individual fish movements of up to 28.3 km and substantial amount of mixing within the population. At this time the evaluation of movement patterns and seasonal distribution of Westslope cutthroat trout within the upper Fording River is in the preliminary stages of investigation (e.g. 6 months of a planned 36 months). Radio tags (Lotek MST-930, 390 day life-span) were applied to 60 sub-adult and adult fish ranging from 234 to 485 mm fork length within the main stem upper Fording River Sections S1 through S10 and lower Henretta Creek (including Henretta Lake). There were 21 males (35%), 33 females (55%) and 6 unidentified sex (10%). Fish life stage was classified based on gonad development during the internal exam and included; 11 sub-adults (18.3%), 7 maturing or first spawners next spring (11.7%), and 42 mature (70%). Home range will be reported on an annual basis following 12 months of monitoring; therefore home range will be reported on for the first time in Interim Report 2 (Q2, 2014). The project team is currently monitoring 56 radio tagged fish located between rkm 22.0 (lowermost Section (S1) above Josephine Falls) and rkm 72.0 (headwaters Section S11). Seasonal movement patterns between summer rearing habitat (August–September) and over-wintering habitat (November–January 15) are presented (mean=4.76 km, range 0.00–28.30, n=56) to illustrate preliminary results are meeting expectations for a migratory fluvial life-history strategy. Dynamic ice conditions, the presence or absence of surface water, potential ground-water influence and water depths appear to be influencing over-winter habitat selection by sub-adult and adult fish. An alternative explanation that headwater sections and tributaries may contain adults with smaller size-at-maturity and are less migratory has not yet been ruled out. In Year 2, additional effort has been allocated to sample the headwater section of the upper Fording River and tributaries. It is anticipated that after three years (i.e. three replicate radio tag groups for a total of n=180) if repeating patterns of movement and seasonal distribution can be identified then critical habitats necessary for the completion of life-history functions (e.g. spawning, over-wintering, rearing) can be identified with confidence. Mortality rates between habitats with multiple fish and repeating patterns of annual use (i.e. habitats categorized as “critical”, “limiting” or “important”) will be compared to those habitats with lower use categorized as “alternative” or “low utilization” habitats. If differences in mortality risk can be demonstrated this will support the designation of critical habitat. Aerial imagery was captured in September 2012 for the length of the main stem upper Fording River, the lower fish bearing reaches of tributaries and the associated riparian areas. A total area of 134.3 km2 was captured on digital colour images with an image pixel size of 10 cm ground sampling distance. Using this imagery, the meso-habitat will be classified and mapped using a standard suite of overview level habitat measurements. The goal is to create a map containing all available fish habitat within the upper Fording River and the lower reaches of tributaries. Mapping of the main stem river and tributaries will be completed in 2013 and 2014. Subsequently, this data could be used to contrast habitat availability with seasonal fish distribution (habitat utilization). This would facilitate comparison of available habitat among river segments and enable analysis using resource selection methods. The current state of knowledge, relating to the specific study questions identified by the project Steering Committee is presented in Table I. This table is a tool used to illustrate annual progress towards answering the study questions in a concise summary. It is important to note that these are early, preliminary results and further work is required and planned for Years 2 through 4 of the study. As a result, these preliminary summaries are expected to be refined and/or changed in subsequent interim reports as the study progresses toward the final report in 2016. The details regarding the status of each question are provided in the main body of the report. |
