Quirk Creek Brook Trout Suppression Project
THE QUIRK CREEK BROOK TROUT SUPPRESSION PROJECT is a collaborative effort involving the Fish & Wildlife Division of Alberta Sustainable Resource Development and Trout Unlimited Canada (TUC).
TUC staff has spent considerable time administering the fish identification test to volunteer anglers, coordinating and supervising outings, sampling harvested brook trout, and collecting and entering creel data. Initiated in 1998 and now entering its 15th year, this project would not have been possible without the participation of many volunteer anglers over the years, and in particular those dedicated anglers who have harvested most of the brook trout in recent years on unsupervised outings. Funds from Anadarko Canada Corporation, the Alberta Conservation Association (Grant Eligible Conservation Fund), TUC's Coldwater Conservation Fund and the Parks Venture Fund have supported this project in the past. We have also had countless hours of effort from TUC members and volunteers, members of local Fish and Game clubs, and field students from the University of Calgary.
Brook trout were introduced to Alberta in the early 1900s and, as a result of extensive stocking, are now present in many foothills waters. In southern Alberta, brook trout populations have generally increased over time while native Westslope cutthroat trout and bull trout populations have declined in most waters where brook trout are present. Brook trout life history attributes-early spawning age, small size at maturity and low catchability has resulted in many quality fisheries for native bull trout and cutthroat trout being replaced with fisheries for smaller, less-catchable, non-native brook trout.
Brook trout colonized Alberta's Quirk Creek subsequent to their introduction to the Elbow River watershed in 1940. Although native cutthroat trout and bull Trout were the only fish captured in Quirk Creek in 1948, by 1978 brook trout had colonized the lower 3 km of the creek and by 1995 they had spread throughout the entire creek, comprising more than 90% of the fish population. This change occurred despite the implementation in 1987 of reduced bag limits and minimum size limits for native trout.
Since 1998, harvest of all fish has been prohibited in Quirk Creek, except by anglers participating in the Brook Trout Suppression Project. Management programs to reduce or eliminate non-native trout populations often involve piscicides (a specialized poison that targets fish) and/or electrofishing. However, in 1986, a published study (Larson et al.) suggested that experimental angling programs might offer a cost-effective, alternative method for reducing densities of non-native trout. Although Larson's study only ran nine weeks, it appeared that anglers reduced the non-native trout population by about 10%.
Since piscicides are only suitable in certain situations and there are insufficient resources to attempt removal of non-native trout by electro fishing in all streams where native trout populations appear to be threatened, the option of selectively removing non-native trout by angling provides an appealing alternative. The objective of the Quirk Creek Brook Trout Suppression Project was to determine whether anglers could selectively harvest enough non-native brook trout to facilitate recovery of the native cutthroat and bull trout population.
Angling, in particular unsupervised outings, appears to be sufficient on the lower reach to keep the number of large book trout at a relatively low level. Based on the fishing pressure and harvest in 2006, it appears that about 100 angler hours per hectare may be sufficient to keep the brook trout population from rebounding to previous high levels, whereas it took about 200 to 300 angler hours per hectare at the start of the study to reduce the population, when the number of large (>150 mm) brooktrout was about four to six times higher. The data from this project also suggest that it is necessary to harvest at least 50% of the large (>150 mm) brook trout population to have an effect on the population.
For the more remote upper reach, however, it was difficult to maintain sufficient angling pressure and harvest to significantly reduce and keep the brook trout population at low levels. For this reason, brook trout removal using one-pass electro fishing was also conducted in the upper reach from 2004 until 2008. Although this reduced the brook trout population substantially, since 2008, no brook trout have been removed by angling or electro fishing from the upper reach of Quirk Creek. The objective is to allow the upper reach to serve as a control, against which the effectiveness of angler removal of brook trout from the lower reach can be evaluated.
The approach used in the suppression project has the potential to work, provided that the streams selected are readily accessible by anglers (relatively close to a road) and sufficient angling pressure can be exerted over multiple years. To this end, the Stewardship License Pilot Project was initiated in 2009, permitting qualified anglers to harvest an unlimited number of brook trout from specified streams.
Listed below are the most up to date statistics for the Quirk Creek Brook Trout Suppression Project:
To download or view a PDF of the latest reports on the Quirk Creek Brook Trout Suppression Project, click here.
For information on how you can take part in the Quirk Creek Brook Trout Suppression Project, or the Stewardship License Pilot Project, contact Brian Meagher via email or at 1-800-909-6040 .