No ingested micro- and macro-plastics detected in three shark species from the Bass Strait, Australia

Plastic pollution is increasingly documented across marine environments, yet exposure data remain absent for most shark species. We examined the gastrointestinal contents of 44 juvenile sharks representing three species: gummy shark (Mustelus antarcticus), southern saw shark (Pristiophorus nudipinnis), and elephant (or ghost) shark (Callorhinchus milii) collected as bycatch from demersal trawl and longline fishing in the Bass Strait off north-eastern Tasmania in September 2018. Gastrointestinal tracts were excised intact and contents rinsed through stacked sieves and examined for micro- and macro-plastics (>1 mm). No plastics were detected in any of the 44 individuals examined. While these null results may reflect genuinely low exposure in this region, we emphasise that reporting such findings is essential for establishing baseline conditions against which future change can be measured. Given the commercial and ecological importance of these species in southern Australian waters, repeat sampling over time is strongly encouraged to detect any emerging trends in plastics exposure.