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Accounting for cohort-specific variable growth in fisheries stock assessments: a case study from south-eastern Australia
journal contributionposted on 2023-05-19, 08:51 authored by Whitten, AR, Klaer, NL, Tuck, GN, Day, RW
Modern statistical ﬁshery stock assessment models rarely account for temporal variability in mean length-at-age, and almost never describe cohort-speciﬁc effects. This study employs techniques for discerning temporal change to mean length-at-age from ﬁsheries data and introduces recently developed stock assessment methods to account for this variability. Using Stock Synthesis, a statistical catch-at-age modelling framework, a stock assessment to account for cohort-speciﬁc variability in mean length-at- age was developed for blue grenadier, Macruronus novaezelandiae, an important commercial species in Australia’s Southern and Eastern Scaleﬁsh and Shark Fishery. Key outputs of a standard stock assessment model that assumes static growth were compared to those of an alternative model that accounts for observed variability in length-at-age. Comparisons show that accounting for variable growth provides a better ﬁt to time-series data and results in signiﬁcant differences to key population estimates. These differences have implications for the estimation of quantities important to management and thus to scientiﬁc advice regarding recommended catch levels.
Publication titleFisheries Research
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherElsevier Science Bv
Place of publicationPo Box 211, Amsterdam, Netherlands, 1000 Ae
Rights statementCopyright 2012 Published by Elsevier B.V.