Quantitative comparison of aquatic sampling gears
Abstract:A method to determine the relative difference in capture efficiency between two aquatic sampling gears is presented. The principle is to perform a number of paired comparisons between two gears by conducting catching operations at the same time and place. It is argued here that the median of the efficiency ratios from the paired comparisons is an appropriate estimator of the true difference in gear efficiency, and that non-parametric methods are suitable for statistical analysis of the results. The presented method is applied, together with two parametric methods, to data from two different comparison experiments; a comparison between two research vessels and a comparison of two different longlines. Estimates of relative differences in gear efficiencies between aquatic sampling gears can be used to improve density measurements of organisms, investigate differences in gear selection properties and analyse differences in economic effectiveness of commercial fishing gears.
Document Type: Research Article
Publication date: September 1, 2002