Cross-shelf transport of larval biota during formation of a Leeuwin Current eddy

Holliday, D., Beckley, L.E. and Feng, M. (2007) Cross-shelf transport of larval biota during formation of a Leeuwin Current eddy. In: AMSA2007, 9 - 13 July, Melbourne, Australia.

Abstract

The formation of a meso-scale anti-cyclonic (warm core) eddy of the Leeuwin Current off Perth, Western Australia in May 2006 was the subject of intensive investigation during a 25-day multi-disciplinary research voyage. Using satellite-tracked drifters, neuston, bongo and opening and closing EZ nets, eddy–induced crossshelf transport of finfish and invertebrate larvae (e.g. rock lobster phyllosoma) was examined. Lagrangian flow characteristics of the anti-cyclonic meander of the Leeuwin Current indicated that it remained attached to the main current with flow returning back onto the shelf during the period of field investigation. In addition, a trend of decreasing drift speed from the perimeter of the meander to the centre was identified. Spatial distributions of fish larvae within and between water masses showed greatest concentrations to be located in shelf waters and within the meander. Vertical stratification of fish larvae revealed the greatest concentrations to occur within the well mixed layer to a depth of 100 m. Patterns in vertical distributions of fish larvae suggest an interaction between oceanography and larval behaviour. Linking vertical distributions of larvae with corresponding depthstratified current velocities (ADCP data) will enable quantification of the cross-shelf transport of larvae.

Item Type:	Conference Item
Murdoch Affiliation(s):	School of Environmental Science
URI:	http://researchrepository.murdoch.edu.au/id/eprint/15094

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