Project number: 2011-016
Project Status:
Completed
Budget expenditure: $292,372.00
Principal Investigator: John Keesing
Organisation: CSIRO Oceans and Atmosphere Hobart
Project start/end date: 30 Sep 2011 - 14 Oct 2012
Contact:
FRDC

Need

Dhufish is one of the most commercially and recreationally important finfish in Western Australia. Together with pink snapper it accounts for almost half of the commercial catch of the west coast demersal scalefish. Recently, commercial and recreational fishers reported that they moved further offshore to catch dhufish suggesting heavy fishing in nearshore areas and the threat of overfishing offshore amplified with increasing use of GPSs. Another concern is a drop in the maximum observed age of dhufish by 9 years from 41 to 32 years old and a decrease in the proportion of dhufish > 13 years of age in the catches from 28 to 9% over the last decade. The limited knowledge of this species points to very limited dispersal over its range enhancing concerns about the vulnerability of dhufish to overexploitation. Understanding the physical and biological processes that underpin recruitment success in dhufish is of key importance to making predictions about the future productivity and management of the fishery. Recent research indicated that the recruitment strength will depend on spawning output of adults, oceanographic conditions and food availability during the planktonic stage. Lack of knowledge of location and transport of eggs and larvae fundamentally limits understanding of the recruitment of dhugfish. The project aims at locating the early life stages and their transport areas such that sustainability for this species can be pursued.

Objectives

1. Finding early life stages
2. Unravelling transport areas of eggs and larvae and correlating it with physical and biological processes
3. Predicting larval sources and sinks and relating it to currents, salinity, temperature, chlorophyll and food

Final report

Authors: Joanna Strzelecki Ming Feng Oliver Berry Liejun Zhong John Keesing David Fairclough Alan Pearce Dirk Slawinski Nick Mortimer

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