Summary of Abstract Submission

Abstract Submission No. IO50-04-0021PresentationOral


Lynnath E. Beckley*1, David Holliday2, Alicia Sutton2, Pearse Buchanan2, Peter A. Thompson3

1 Murdoch Univeristy, Australia
2 Murdoch University, Australia
3 CSIRO, Australia


The anomalous Leeuwin Current flows southward along the edge of the continental shelf of Western Australia. A multi-disciplinary examination of the Leeuwin Current system along the Western Australian continental shelf and adjacent ocean (2234S) during the late austral autumn incorporated physics, nutrients, primary production and a depth-integrated, bongo-net survey of the macro-zooplankton. Larval fishes were diverse comprising >200 taxa from 114 neritic and oceanic teleost families. A two-factor PERMANOVA indicated structuring of larval fish assemblages with latitude and across isobaths with a significant interaction term. The krill assemblage of the Leeuwin Current system was diverse with 27 species identified, including nine species with tropical affinities. Pseudeuphausia latifrons, a tropical coastal species, was found at all stations emphasising the influence of alongshore and cross-shelf transport associated with the Leeuwin Current. Of the 19 chaetognath species identified from the Leeuwin Current system, six were new records for the region. Although there was a high degree of similarity (>75%) of the assemblage across the study area (with Flaccisagitta enflata numerically dominant), some chaetognath species displayed distinct tropical or temperate affinities. Overall, this study with concurrent physical and chemical oceanography, primary production and macro-zooplankton studies has demonstrated broad-scale advection of planktonic biota, both across the shelf, and alongshore, in the SE Indian Ocean.