Estimation of Monkfish Absolute Abundance from Trawl Surveys
Speaker: Joyce Yuan (CREEM)
Since 2005, stratified random trawl surveys of the monkfish stock which occupies the northern European shelf have been conducted annually to obtain age-structured estimates of absolute abundance for this stock. Survey data are unusual in that almost all fish are aged as well as lengthed. We describe an estimation method which incorporates statistical models for herding, length-based selectivity and missing age data and incorporates uncertainty from all of these sources in variance estimation. Design-based estimates are presented and model-based methods are investigated as an alternative.