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Nonchemical Eradication of an Introduced Trout from a Headwater Complex in Banff National Park, Canada
Author(s) -
Pacas Charlie,
Taylor Mark K.
Publication year - 2015
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1080/02755947.2015.1043412
Subject(s) - electrofishing , salvelinus , trout , fishery , fontinalis , national park , drainage basin , geography , catch and release , habitat , shore , ecology , population , streams , environmental science , fish <actinopterygii> , biology , recreational fishing , demography , cartography , sociology , computer network , computer science
Nonnative salmonids have been intentionally introduced in North America for over a century and are now implicated in the decline of native aquatic species. Current management objectives for some national parks are to remove invasive species, where feasible. We evaluated the use of mechanical methods (gill nets and electrofishing) to eliminate a naturalized population of nonnative Brook Trout Salvelinus fontinalis in a subalpine headwater basin. We required a total of 1,383 continuous net nights/ha (net nights = number of nets × number of nights) over 5 years to completely eradicate 1,527 Brook Trout from both Lower (9.7 ha; 6 m maximum depth) and Middle (23.1 ha; 25 m maximum depth) Devon Lakes, Alberta, Canada. Electrofishing along the shoreline of both lakes resulted in the capture of 301 Brook Trout over 4 years. We required a total of 52.1 h/km of electrofishing over 5 years to completely remove 3,288 Brook Trout from the upper 4.5 km of the Clearwater River. We verified the absence of fish in the lakes with 1,558 net nights/ha of sampling over 4 years and in the river with 13.6 h/km over 2 years. This project confirms that mechanical methods are a viable option for removing introduced fish, even in relatively large (up to 20 ha) and deep (up to 25 m) mountain lakes. We surmised that our success (relative to that of projects described in the literature) was due to (1) the relatively simple alpine habitat, in which river and lake margins were clear of macrophytes, suspended sediment, and overhanging riparian vegetation, and (2) the sheer magnitude of our effort.