Statistical inference about the relative efficiency of a new survey protocol, based on paired-tow survey calibration data

摘要

Paired-tow calibration studies provide information onudchanges in survey catchability that may occur because of some necessary change in protocols (e.g., change in vessel or vessel gear) in a fish stock survey. This information is important to ensure the continuity of annual time-series of survey indices of stock size that provide the basis for fishudstock assessments. There are several statistical models used to analyze the paired-catch data from calibrationudstudies. Our main contributions are results from simulation experiments designed to measure the accuracy of statistical inferences derived from some of these models. Our resultsudshow that a model commonly used to analyze calibration data can provide unreliable statistical results when there is between-tow spatial variation in the stock densities at eachudpaired-tow site. However, a generalized linear mixed-effects model gave very reliable results over a wide range of spatial variations in densities and we recommend it for the analysis of paired-tow survey calibration data. This conclusion also applies if there is between-tow variation inudcatchability.