Inclusion of skipper effect in the GLM standardisation of the CPUE abundance indices for orange roughy off Namibia
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2007
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University of Cape Town
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Abstract
Various GLM analyses are used to standardise the CPUE data for Namibian orange roughy to investigate the impact of using information on skippers rather than on vessels. The inclusion in the GLMs of a skipper factor rather than a vessel factor results in lower CPUE indices for the most recent years. Classifying skippers as experienced or inexperienced in orange roughy fishing does not have an appreciable impact on standardised CPUE trends. However, classifying individual initially inexperienced skippers as experienced after their first year in the fishery results in lower CPUE indices, in particular for the last four years. In broad terms, there is not a clear difference between skippers pre-classified as experienced or inexperienced.
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Brandão, A., & Butterworth, D. S. (2007). Inclusion of skipper effect in the GLM standardisation of the CPUE abundance indices for orange roughy off Namibia. MARAM: University of Cape Town.