A stock assessment model for Northeast Atlantic spurdog, incorporating fecundity data to estimate the extent of density dependence in pup production ...

• Main Authors: De Oliveira, José A. A., Ellis, James R., Dobby, Helen
• Format: Conference Object
• Language: unknown
• Published: ASC 2010 - Theme session E 2024
• Subjects: Fisheries and aquaculture; Pressures, impacts, conservation, and management; Northeast Atlantic; Squalus acanthias
• Online Access: https://dx.doi.org/10.17895/ices.pub.25068857; https://ices-library.figshare.com/articles/conference_contribution/A_stock_assessment_model_for_Northeast_Atlantic_spurdog_incorporating_fecundity_data_to_estimate_the_extent_of_density_dependence_in_pup_production/25068857

No abstracts are to be cited without prior reference to the author.An exploratory assessment model for Northeast Atlantic spurdog (Squalus acanthias) is presented. The model is based on an approach developed for school shark (Galeorhinus galeus) off southern Australia. It is essentially age- and sex-structured, but is based on processes that are length-based, such as maturity, pup production, growth (in terms of weight) and gear selectivity, with a length–age relationship to define the conversion from length to age. Pup production (recruitment) is closely linked to the numbers of mature females, but the model allows deviations from this relationship to be estimated (subject to a constraint on the amount of deviation), and parameter estimates to be based on fitting fecundity data. The model fits to a combined Scottish groundfish survey index of abundance, and to proportion-by-category data from both the survey and commercial catches (aggregated across gears). The only estimable parameters considered are total ...