Evaluation of sampling gears for fish population assessment in Alaskan streams and rivers

Abstract

During summers, 1982 and 1983, a variety of habitats were sampled on the Tanana and Kenai River drainages to evaluate sampling gears used for fish population assessment in Alaskan streams and rivers. Experiments were conducted to investigate sampling efficiency, length and species selectivity, and injuries to fish by three active (backpack electroshocker, electrofishing boat, seine), and two passive (minnow trap, fyke net) gear types. Gears were compared using a common set of attributes: accuracy, portability, scope or species detection, labor required, fishing power, fish savings (low mortality), and initial cost. Electrofishing systems were best for species detection and fishing power, while passive gears had higher catch per hour of labor. Large fyke nets and seines were effective under limited environmental conditions. A linear model was developed to assist in selecting an optimum fishing gear, or array of gears, for any level of fisheries population assessment, considering all applicable sampling constraints.