The tropical marine finfish (TMF) project has continued to increase its focus on industry development and the extension of marine finfish culture technology.
In 2006–07, approximately 30 000 juvenile fish were supplied to industry for pond-based growout using existing prawn farm infrastructure.
The majority of these fish were estuary cod (Epinephelus coioides) and were supplied to an industry partner in Cardwell. These fish should reach market size by December 2007.
This was also the year when the first aquaculture produced grouper in Australia were sold into the Sydney–Melbourne market. These flowery cod (E. fuscoguttatus) were grown by an industry partner at Mossman from juveniles supplied by the TMF project.
The product was well received in the market, with demand far exceeding the limited supply. The taste and quality of the fish was praised, although the size (400–600 g) was considered rather small.
A small population of flowery cod are currently being grown in DPI&F ponds at Oonoonba. These fish are being grown in floating cages where growth is likely to be much faster than that of free-ranging fish grown at low density in a pond.
A major increase in broodstock numbers has been accomplished. As reported last year, research effort on barramundi cod (Cromileptes altivelis) was to be phased out. The barramundi
cod broodstock were put out to tender and sold, allowing for increased numbers of the targeted grouper species. Numbers of flowery cod were increased slightly and a population of F1 fish were established as future broodstock. A major increase in numbers of estuary cod was achieved through the purchase of newly caught fish and through a donation of broodstock from our industry partner in Cardwell.
A population of coral trout (Plectropomus leopardus) was acquired to target their spawning season. Queensland grouper (Epinephelus lanceolatus) was identified in the TMF project review as a priority grouper species.
This species has not previously been part of the TMF project focus and presents a number of major diffculties. The protected listing of the species has prevented its collection from the Great Barrier Reef Marine Park (GBRMP).
Collection is currently only possible in a few small zones annexed from the GBRMP and from areas outside the park (such as the Gulf of Carpentaria).
To facilitate collection of broodstock, the project has acquired a live-fish transport truck and upgraded the quarantine facilities to hold larger fish. The first Queensland grouper collection trip was to the Townsville Port where, with the cooperation of the Townsville Port Authority, a fourday fishing effort resulted in the capture of a single large (95 kg) fish. This fish is currently housed in a broodstock tank at the Northern Fisheries Centre.
Further collection trips to Weipa are scheduled for 2007–08.
Commissioning of the new larval rearing tanks has been successful and has enabled the production and supply of increased numbers of juveniles to industry. A second set of larval tanks has been ordered for delivery in 2007–08 and will further increase capacity. Noda virus has continued to be a major problem, resulting in mortalities of around 50% when juvenile fish have become infected.
To combat the virus, ozone washing of eggs prior to their addition to the larval tanks was instigated; results are encouraging, with larvae testing negative to the virus.
The TMF project continues to benefit from its links with the ACIAR project ‘Improved hatchery and growout technology for marine finfish aquaculture in the Asia–Pacific region’ with staff exchanges enabling access to advances being made in grouper aquaculture within the region. A technical member of the TMF team attended a three-week grouper aquaculture training workshop in Situbondo, Indonesia.
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