Scientific Sampling Effects: Electrofishing California's Endangered Fish Populations

Standard methods used by biologists around the world for sampling fish populations and determining fish and habitat relationships primarily involve electrofishing. With the recent listings of coastal salmon and steelhead as threatened or endangered, one must ask how electrofishing-induced injury to fish in rare populations relates to “take” under the U.S. Endangered Species Act. Issues related to electrofishing are under discussion in California as federal and state agencies determine how to approach permitting for monitoring and research activities in rivers containing protected fish populations. Many problems have been discussed in the literature based on short-and long-term injury to individual fish from different forms of electrofishing. To date no standard approach for this technology exists that will allow effective surveys without probable injury to some portion of the fish population. How electrofishing injuries made at the individual fish level translate into population effects has not b...