The accuracy of abundance estimates is obviously of central importance to fisheries management, but estimates based on CPUE data are problematic because standardized CPUE data do not account for increased efficiency in the fishing fleet or for spatial and temporal intensification (Pennington and Stromme 1998, Neis et al. 1999b, Neis and Kean 2003). In addition, range contraction in remaining stocks may keep landings in mobile trawl fleets high, despite depletion (Hutchings 1996, Bennet 2008).