The recent declines in the abundance, average size and recreational and commercial catches have raised the question of the sustainability of sand flathead stocks in Port Phillip Bay. New information regarding the longevity of this species raises further questions as to their sustainability. It is expected that the introduced and expanding populations of exotic species (eg Asterias, Sabella and Corbulla) (Cohen et al. 1998) may also impact on sand flathead given their abundance and habitat requirements.

The recent decline in the commercial catch of rock flathead has also raised the question of sustainability of the fishery within Corner Inlet. The suggestion that the decline in rock flathead catches in the 1970’s was due to the loss of seagrass beds within Corner Inlet (MacDonald, 1997), highlights the need to understand the links between habitat and recruitment.

Surprisingly, there are few publications on sand and rock flathead and there is no information on the population dynamics of the local stocks of rock flathead. There is a growing need to undertake research on these potentially vulnerable species because of their longevity and catchability, and to identify appropriate sustainability indicators. There is also a lack of detailed analysis of catch and effort data for both species. Given the lack of preliminary data analysis, there have been no attempts at stock assessment of these important recreational and commercial species to support management strategies. This research proposal attempts to address these information gaps and to incorporate the biological data into an integrated age-based, population dynamic model that could be used to manage both the sand and rock flathead fisheries, and to determine whether the current levels of fishing are sustainable.

References

Cohen, B. F., Currie, D. R. and McArther, M. A. (1998). Epibenthic community structure in Port Phillip Bay, Victoria, Australia. MAFRI. Victoria. Int. Rep. No. 10.

MacDonald, M. (1997). Corner Inlet/Nooramunga fin fisheries - 1994. VFRI. Queenscliff. Assess. Rep. No. 3.