MEPS 199:231-242 (2000)  -  doi:10.3354/meps199231

Determination of spawning areas and larval advection pathways for King George whiting in southeastern Australia using otolith microstructure and hydrodynamic modelling. I. Victoria

Gregory P. Jenkins1,*, Kerry P. Black2, Paul A. Hamer1

1Marine and Freshwater Resources Institute, PO Box 114, Queenscliff, 3225 Victoria, Australia
2Centre of Excellence in Coastal Oceanography and Marine Geology, Ruakura Satellite Campus, University of Waikato, PB3105 Hamilton, New Zealand

ABSTRACT: We used larval duration estimated from otoliths of post-larval King George whiting Sillaginodes punctata collected from bays and inlets of central Victoria, Australia, and reverse simulation with a numerical hydrodynamic model, to estimate spawning sites and larval advection pathways. Larval duration increased from west to east for post-larvae entering Port Phillip Bay, Western Port and Corner Inlet. The period of recruitment to bays and inlets was relatively fixed; the longer larval durations were associated with earlier spawning times. Larval durations for post-larvae entering Port Phillip Bay were longer for 1989 compared with 1994 and 1995. Reverse modelling based on larval durations for the 3 bays in 1995 suggested that most post-larvae were derived from spawning in western Victoria and southeastern South Australia. The centre of the predicted spawning distribution was ca 400 to 500 km from the recruitment sites and the region of intense spawning was spread along approximately 300 km of coastline. For Corner Inlet, however, a small proportion of the spawning may have occurred in central Victoria, within 200 km of the recruitment site, with larvae transported in a clockwise gyre around Bass Strait. The predicted spawning area for post-larvae from Port Phillip Bay was similar in the 3 yr examined.

KEY WORDS: Spawning area · Larval advection · Hydrodynamic numerical modelling · Otolith microstructure · Southeastern Australia · Sillaginodes punctata

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