An Evaluation of Several Types of Gear for Sampling Fish Populations, 1974

(1974) An Evaluation of Several Types of Gear for Sampling Fish Populations, 1974. Natural Resources, Department of

Preview

PDF iowa_fisheries_research_tech_series_no_74-2_1974_OCR_.pdf File Size:13MB

Abstract

Sampling fish populations with seines, fyke nets and gill nets to determine changes or trends in apparent abundance is a basic tool in fisheries management and research. Reliable estimates of abundance are difficult to obtain primarily because of the lack of standardized sampling techniques and gear , and from a general dearth of knowledge about the sources of variation in catch other than changes in population abundance. Standardization of techniques and gear within a sampling regime is necessary to achieve precise estimates of r elative abundance and other population parameters. Recognition and delineation of inherent sources of variation in catch per unit effort are also prerequisites for obtaining precise indices.