By: the Elk River Alliance
The collapse in the observed number of juvenile and adult westslope cutthroat trout in the Upper Fording River in 2019 (declines of 74 per cent and 93 per cent, respectively), reported from Teck Resources Ltd. monitoring studies, is of great concern to the Elk River Alliance (ERA). This species has been listed as threatened under the Federal Species at Risk Act, as well as being blue listed provincially.
We concur that this sudden collapse is puzzling, given that the population appeared to be improving since the 2013 flood. In 2017 Teck reported a stabilizing adult population and an observed threefold increase in juveniles from 2013 to 2017 (according to the Upper Fording River Westslope Cutthroat Trout Population Monitoring Project: 2017 report).This was despite the fact that selenium concentrations were a minimum of ten times over the water quality guideline of two ug/L in the Upper Fording River during the study period (20-70 ug/L, depending on the season). Water quality guidelines are set by the B.C. government to, amongst other objectives, protect aquatic life, wildlife, and their habitats. Exceedances may risk the health of aquatic life, particularly over the long term.
Despite the population increases, while the adult population abundance appeared to be stabilizing, the range of fish density estimates [22-28 fish per kilometre from 2012-2017] was much less than reference targets [45- 95 fish per kilometre], as noted in the 2017 report. These reference targets reflect the abundance needed to ensure that the population remains at a level that can provide a sustainable recreational fishery without risk of severe population decline. This is especially important given the cultural, recreational, and economic importance of the fishery in the Elk Valley.
The Elk River Alliance emphasizes the vital importance of “pulling out all of the stops” to identify the reasons for the collapse. We suspect that the collapse may be due to cumulative effects of a combination of stressors, including but not limited to selenium and calcite related to mining operations. Other stressors which may be contributing to the collapse include predators, low to no flow in spawning and rearing habitats at certain times of the year, changes in stream temperatures, reduction in the number or quality of overwintering areas, and the effects of recent logging practices in the watershed.
This collapse is a warning for all users of the entire Elk River system. If the Upper Fording, and now Harmer and Grave Creeks, are experiencing significant declines in both adult and juvenile populations, could this be a bellwether for this species’ wellbeing in the Elk River main stem? For years, the Elk River Alliance has been calling on Teck and government agencies to make a concerted effort to evaluate the westslope cutthroat trout population in the Elk River. We have noted the importance of tributaries like Lizard, Morrissey, and Alexander as spawning and rearing streams. More broadly, we have repeatedly called for effective management of cumulative effects in the watershed from a range of industrial and community activities.
The response from the provincial government fish biologists has been that it is very difficult to gather population data for westslope cutthroat trout in the mainstem Elk River. It is time to figure out what is possible and to put in place innovative approaches. It is also a time to consider greater protection of important tributaries to the Elk River. Teck’s public reporting of its monitoring results, and its commitments to construct and operate additional water treatment facilities to remove selenium and prevent calcite formation continue to be of utmost importance. It is now time for the provincial government to act on its commitment to manage cumulative effects in the Elk Valley in concert with industry, academics and relevant stakeholders in the watershed, to gather information on fish populations and angling success, and put in place measures to ensure the long term viability of the threatened westslope cutthroat trout.
The Elk River Alliance stands ready to work with the provincial government and a coalition of interests to move forward on these actions.