Mr Jim Raptis of Raptis and Sons Pty Ltd claims that fuel costs aline in the Northern Prawn Fishery (in which his company operates) are $2million pa. It is conservatively estimated that improved net designs may result in fuel savings of at least 10%: a saving of at least $200,000 pa. Such fuel reductions will also have favourable consequences both directly and indirectly through favourable public exposure, in meeting targets for reduction of greenhouse gas emissions. We believe that these are good reasons for extending the research already done in Gulf St Vincent to trial novel net designs based on improved "Spectra" twine, a material that offers greater strength and less drag than conventional netting. Although it is propsed that the research be done in Gulf St Vincent, using commercial vessels engaged in the fishery, the results will have clear implications for other prawn fisheries such as the NPF. With a favourable result and strong industry endorsement, it is likely that the nets will be rapidly adopted in other prawn fleets around Australia.
The research team assembled has an impressive track record of achievement in gear design and application in prawn fisheries. We propose to trial three net configurations including a conventional mesh net, 50mm Spectra, and 60mm Momoy netting. We will compare prawn size selectivity an fuel consumption over at least 5 nights in Gulf St Vincent later this summer.
This project aims to provide the biological knowledge to sustainably manage a new species in South Australian fisheries production. It also aims to maximise returns for a species which, until recently, yielded low returns to fishers but has significant potential in export markets.
Targeted fishing effort on the cuttlefish Sepia apama has rapidly increased in northern Spencer Gulf during recent years. Annual reported catches have increased from less than 4 tonnes to more than 250 tonnes within 5 years. Licence holders in the fishery have expressed strong concerns over the sustainability of the fishery which is restricted to a spatially small area near Pt Lowly. The fishery is currently managed within the broad management framework of the commercial marine scalefish fishery, which provides for no specific restrictions on either effort or catch for cuttlefish. More stringent management controls, specific to this species, need to be introduced before the commencement of the 1998 fishing season.
There is a complete lack of scientific information regarding the general biology and life history characteristics of S. apama, despite its large size and common occurrence in southern Australian waters. Other commercial cuttlefish species are known to be short-lived and semelparous (spawns once and dies), a lifecycle common to many cephalopods. With this type of lifecycle, overfishing in a single year can cause a stock to collapse (Rodhouse and White, 1995). In addition, the exploited population is understood to be a spawning aggregation, which would further increase the potential to deplete the stock.
An improving market for this species, including the potential for an export market, suggests that exploitation levels will continue to increase. Additionally, other known populations within South Australia and other southern States (currently unfished) may attract fishing effort. There is therefore an urgent need to establish the general life history characteristics of S. apama in South Australian waters, and gather baseline biological data upon which the impacts of fishing on this species may be assessed and any necessary management controls may be based.
Currently South Australian cuttlefish are attracting a much lower market price than other cuttlefish species of a similar size being sold in Japanese and European markets (AUS$1-2 as compared with US$5-7). Therefore, there is a definite need to investigate possible marketing strategies which would increase the price of the current product and/or identify alternative value-added products (especially if they utilise other parts of the cuttlefish currently being discarded). An even more exciting opportunity may exist with the live fish trade.
Rodhouse PG and White MG (1995). Cephalopods occupy the ecological niche of epipelagic fish in the Antarctic polar frontal zone. Biol. Bull. 189: 77-80.
After southern bluefin tuna, King George whiting is the most important fish species in South Australia. This species attracts a high market price on local and interstate markets and has biological attributes which suggest that is has good potential as a candidate for aquaculture. To allow commercialisation of this species, there is an immediate need to commence research to control egg production and conduct larval rearing trials to expose and solve culture problems so that a valid assessment of this species can be provided to aquaculturalists and investors.
FRDC funded research on the reproductive biology of wild King George whiting has identified a need to determine the spawning frequency of individual fish to get accurate estimates of fecundity.
There is a need to recognise that aquaculture is the only way to increase production of small volume coastal fisheries, such as that for King George whiting, without increasing fishing pressure on natural populations.
There is a need to develop aquaculture of coastal marine finfish species as an option which has potential to allow commercial fishers to diversify and reallocate effort to reduce pressure on wild stocks.
