A three-pass electrofishing removal strategy is not effective for eradication of Prussian Carp in a North American stream network

Prussian Carp Carassius gibelio, also referred to as Gibel Carp, is a destructive aquatic invasive species, recently found in Alberta, Canada. Three-pass electrofishing is a potential approach to control some aquatic invasive fish species in stream habitats. The objectives of this study were to: 1) determine the efficacy of this strategy to control Prussian Carp in connected streams; and, 2) assess whether population size or the distance to the introduction site would influence removal success. We sampled sites using electrofishing in tributaries of the Red Deer River in both the summer and fall and detected Prussian Carp at all sites prior to removal, with > 90 % probability of detection of this species within the first 120 m of electroshocking efforts. Overall, we were not successful at removing Prussian Carp from the sample sites and we found that abundances of Prussian Carp were significantly higher post-removal. Removal success related significantly to distance to the introduction site, suggesting that removal may be useful in targeted situations close to the edge of the invasion front.