Movement and nursery origins of immature snapper in Victorian waters: insights from analyses of otolith microchemistry.

Paul Hamer, Greg Jenkins and Bronwyn Gillanders

University of Melbourne, POINT LONSDALE, AUSTRALIA

THEME: ASFB

The elemental composition of otoliths may provide a natural tagging system for fish. Variation in otolith composition between fish from different nursery areas can enable characterization of nursery specific tags. Analysis of specific regions of otoliths from older juveniles and adults, using laser ablation, can provide information on fish movements and the contributions of different nursery areas to the greater adult population. This presentation discusses the use of natural chemical tags for investigation of the origins and movements of snapper in Victorian waters. Particular emphasis is placed on the investigation of movements of immature fish between the most important fishery, Port Phillip Bay, and oceanic waters, and the assessment of ocean areas as nurseries and potential suppliers of snapper to the Port Phillip Bay fishery.