Standard Methods for Sampling North American Freshwater Fishes, second edition

Chapter 4: Warmwater Fish in Wadeable Streams

Norman Mercado-Silva, John Lyons, Stephan J. Magnelia, James T. Peterson, Allison H. Roy, and Seth Wenger

doi: https://doi.org/10.47886/9781934874769.ch4

Standard methods for sampling warmwater fishes in wadeable streams in this edition remain consistent with those recommended in Rabeni et al. (2009). Although Rabeni et al. (2009) described both backpack and tow-barge electrofishing together as DC electrofishing, here we treat them as two separate methods for sampling warmwater fishes in wadeable streams. Also, Rabeni et al. (2009) was ambiguous in suggesting a waveform to be used when tow-barge electrofishing; here, we present both smooth and pulsed waveforms as recommended methods.

Both “warmwater” and “wadeable” are terms of convenience without precise definition and are used to describe streams that are generally too warm to have salmonid populations and that can be safely traversed by walking during baseflow conditions (i.e., a section of stream should have most of its length less than 1 m deep and it should be possible to cross in chest waders). Warmwater streams in North America are estimated to provide more than a half-million kilometers of fishable waters (Rabeni and Jacobson 1999). Warmwater streams have experienced a surge of attention from fisheries managers in the past four decades because of increased sportfishing opportunities (due, in part, to point-source pollution abatement and the popularity of fishing kayaks) and the use of fish assemblages as indicators of biological integrity for regulatory and management purposes. At least 38 U.S. states and some Canadian municipalities and provinces have fish bioassessment programs (USEPA 2002; Jones and Yunker 2009; Stanfield 2010), and five warmwater fish-based stream biomonitoring protocols have been proposed and validated in Mexico (Mercado-Silva et al. 2006).