Assessing age and growth of the winghead shark (Eusphyra blochii) in the Northern Territory, Australia

The winghead shark (Eusphyra blochii) is listed as critically endangered due to population declines and localised extinctions potentially occurring throughout the Indo-West Pacific.  This species is at high risk for overfishing with populations declining by more than 80% across its range since 1984.  Despite growing concern over the rapid decline and overexploitation of winghead sharks, published literature on this species’ life history, particularly age and growth, remains extremely limited.

 

Length-at-age estimates produced from age and growth studies are essential to fisheries population assessments and are used to model growth and determine longevity, which can indicate a species vulnerability to overfishing.  These estimates have not yet been validated for the winghead shark, and given this species conservation status, producing robust, accurate, and validated estimates is critical for informed stock assessments and effective management strategies.

 

To date there is just one study assessing age and growth of winghead sharks.  This study expand upon that and will represent the first age and growth analysis for the critically endangered winghead shark in the Northern Territory using the largest sample of winghead shark vertebrae assembled to date (n = 186).  By applying modern multi-model and Bayesian statistical frameworks, it will establish methodological best practices for future life history research on this species.