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Comparison of Electrofishing Techniques to Detect Larval Lampreys in Wadeable Streams in the Pacific Northwest
Author(s) -
Dunham Jason B.,
Chelgren Nathan D.,
Heck Michael P.,
Clark Steven M.
Publication year - 2013
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 - 10.1080/02755947.2013.826758
Subject(s) - electrofishing , streams , fishery , sampling (signal processing) , backpack , lamprey , odds , environmental science , range (aeronautics) , ecology , abundance (ecology) , biology , statistics , computer science , geography , mathematics , logistic regression , telecommunications , computer network , materials science , archaeology , detector , composite material
We evaluated the probability of detecting larval lampreys using different methods of backpack electrofishing in wadeable streams in the U.S. Pacific Northwest. Our primary objective was to compare capture of lampreys using electrofishing with standard settings for salmon and trout to settings specifically adapted for capture of lampreys. Field work consisted of removal sampling by means of backpack electrofishing in 19 sites in streams representing a broad range of conditions in the region. Captures of lampreys at these sites were analyzed with a modified removal‐sampling model and Bayesian estimation to measure the relative odds of capture using the lamprey‐specific settings compared with the standard salmonid settings. We found that the odds of capture were 2.66 (95% credible interval, 0.87–78.18) times greater for the lamprey‐specific settings relative to standard salmonid settings. When estimates of capture probability were applied to estimating the probabilities of detection, we found high (>0.80) detectability when the actual number of lampreys in a site was greater than 10 individuals and effort was at least two passes of electrofishing, regardless of the settings used. Further work is needed to evaluate key assumptions in our approach, including the evaluation of individual‐specific capture probabilities and population closure. For now our results suggest comparable results are possible for detection of lampreys by using backpack electrofishing with salmonid‐ or lamprey‐specific settings. Received December 28, 2012; accepted July 10, 2013