AUTHOR=Lipscombe Rebecca S. , Meyer Lauren , Butcherine Peter , Morris Stephen , Huveneers Charlie , Scott Anna , Butcher Paul A. 

TITLE=A taste of youth: Seasonal changes in the diet of immature white sharks in eastern Australia

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1359785

DOI=10.3389/fmars.2024.1359785

ISSN=2296-7745

ABSTRACT=White sharks (Carcharodon carcharias) play a crucial ecological role, shaping ecosystems through direct predation and risk effects. On the east coast of Australia, immature white sharks are broadly distributed, inhabiting a wide range of habitats and ecosystems from temperate southern New South Wales and Bass Strait to tropical North Queensland. Using stable isotopes and fatty acids in muscle and plasma, we examined the diet and habitat use of 136 immature white sharks (152-388 cm total length) captured on SMART drumlines on the East Australian coast. This facilitated the temporal assessment of white shark trophic ecology from a few weeks to approximately a year. Biochemistry of muscle samples showed that white sharks predominantly feed onat low trophic level prey from coastal environments. A seasonal shift in diet was evident, based on high proportions of essential fatty acids in muscle tissues in spring and summer, suggesting that prey items consumed during these seasons are of higher nutritional quality. Plasma fatty acids showed a short-term diet shift from DHA (docosahexaenoic acid) enriched prey in autumn to prey with a higher proportion of 18:1ω9 in winter. By combining stable isotope and fatty acid analysis, we gain a comprehensive understanding of immature white shark diet in eastern Australia. Our results confirm that white sharks are generalist predators that exhibit seasonal shifts in their diet adapt to seasonal changes in prey availability. Their high use of coastal habitats reinforces the importance of these areas for foraging, which is crucial for growth and development during this critical life stage.