Location and transport of early life stages of West Australian Dhufish, Glaucosoma hebraicum.

A combination of methods have been developed and tested to locate for the first time early life stages (eggs and larvae) of West Australian Dhufish Glaucosoma hebraicum and provide a detailed map of their distribution at two sites off south-western Australia.

The project demonstrated that:
- The use of a hydrodynamic model can optimise and guide oceanographic sampling when there is a paucity of knowledge on spawning locations.
- The shipboard detection of larvae allows adaptive sampling maximising the chances of success.
- A properly interpreted particle (larvae) tracking model can throw light on early life history of G. hebraicum.
- There is high variability in the currents along the continental shelf between Cape Leeuwin and Cape Naturaliste (Western Australia), with clear implications for larval transport of West Australian Dhufish and other species important to commercial, recreational and charter fishers.
- There is variability in food supply for fish larvae in the Capes region that has consequences for larval survival.

The project developed:
- A species-specific PCR assay to detect G. hebraicum DNA from mixed zooplankton samples allowing near real time processing of plankton samples.
- A proof of concept for use of quantitative PCR analysis to establish an index of the biomass of West Australian Dhufish eggs and larvae in real time.