Barnett et al 2010B S Frusher.pdf (355.04 kB)
Predator-prey relationships and foraging ecology of a marine apex predator with a wide temperate distribution
journal contribution
posted on 2023-05-17, 04:19 authored by Barnett, A, Abrantes, K, Stevens, JD, Yick, JL, Stewart FrusherStewart Frusher, Jayson SemmensJayson SemmensThe diet of the broadnose sevengill shark Notorynchus cepedianus was investigated over 3 years from 2 coastal locations in south-east Tasmania: the Derwent Estuary and Norfolk Bay. In general, individuals from both locations consumed the same broad dietary categories (sharks, batoids, teleosts and mammals). However, within these categories, species composition differed. Variations in chondrichthyan prey consumed matched estimations of prey abundance: Mustelus antarcticus was the primary prey in Norfolk Bay, where it was also the most abundant prey species; similarly, Squalus acanthias was an important prey and the most abundant in the Derwent Estuary. A decline in the catch rates of N. cepedianus and elasmobranch prey, in particular M. antarcticus over 3 years coincided with declines in dietary occurrence of M. antarcticus. Also, N. cepedianus and M. antarcticus abundances were both higher in Norfolk Bay than the Derwent Estuary. The correlation with diet and estimations of predator and prey relative abundance suggests N. cepedianus may move into coastal areas to exploit regular seasonal abundant resources, but they can also be versatile opportunistic predators that exploit a temporarily abundant resource.
History
Publication title
Marine Ecology Progress SeriesVolume
416Issue
OctoberPagination
189-200ISSN
0171-8630Department/School
Institute for Marine and Antarctic StudiesPublisher
Inter-ResearchPlace of publication
Nordbunte 23, Oldendorf Luhe, Germany, D-21385Rights statement
Copyright © 2010 Inter-ResearchRepository Status
- Restricted