Jungle perch once occurred widely in coastal Queensland rivers, from Cape York to Northern NSW. Central and southern populations have declined or become locally extinct due to dams and weirs blocking migration pathways between saltwater (where they spawn) and freshwater habitats (where they reside as juveniles and adults). Unlike barramundi, mullet and bass; jungle perch cannot persist long-term in saltwater habitats. Barriers lead to rapid local extinction. Construction of fishways on barriers in the past 10 years has created suitable conditions for the reintroduction of jungle perch. There are limited opportunities for natural recolonisation, and remnant adult populations of local strains are too few for translocation to be a practical solution. Restocking from captive bred individuals is the only option to bring back jungle perch fisheries.

Restoring wild jungle perch fisheries is a high priority for recreational fishers in Queensland. Reintroduction of self sustaining populations in rivers in south-eastern Queensland and the Mackay-Whitsunday Region will provide angling opportunities to large populations of anglers. Development of jungle perch fingerling production will also create future opportunities to further enhance Queensland's stocked impoundments and make jungle perch accessible to even more anglers.

Recent research by DEEDI has solved much of the reproductive biology of jungle perch, which can now be spawned regularly in captivity. Jungle perch larvae are much smaller (2.3 mm) than bass and barramundi larvae and establishment of first feeding has been problematic. Strategies to promote larval feeding need to be developed. The transition from larvae to fingerlings is critical for future development of jungle perch fisheries.

Biofouling of aeration equipment is a significant farm management issue and production cost for Australian marine prawn farms. Defouling aeration equipment has a high labour demand and once fouled the energy efficiency of paddle-wheels and other aerating equipment can be markedly reduced, leading to elevated electricity costs and shorter equipment life. The estimated cost of biofouling is a minimum of $1,000 per hectare per crop when considering the additional labour, maintenance and electricity costs that it creates. This cost figure however does not include the impact of aerator fouling on prawn production levels which potentially could be far greater. The industry uses up to 10x aerators per hectare and they consume 70-80% of total farm energy use. It is estimated that at the peak of the production season around 6,000 2hp aerators are in use in ponds across the prawn industry alone.

Ensuring appropriate and timely aerator defouling is conducted is a significant farm issue. Manual defouling is one of the least desired tasks on the farms as it is dirty, laborious and workers are susceptible to multiple skin cuts that are prone to infection. Consequently it can be difficult to maintain staff to undertake this task for any length of time.
There is no data available on the impact of biofouling on the aeration efficiency, for example the oxygen transfer rate, and this information is critical to maximising benefit from mitigation strategies from both a practical and economic stand point.

The relevant industry body, the APFA through the R&D Committee, has assessed prevention of aerator biofouling as a priority issue and has recommended that the project commence as close as possible to the start of the current production season.

The proposed project falls within the Seafood CRC Theme – ‘Aquaculture Innovation’ as the objective is to improve production efficiency.

The prawn industry is being challenged to provide prawn product that maintains premium quality throughout an extended storage-life. Significant revenue loss for farmed prawns within the retail sector occurs through product not meeting market colour specification and also severe price reduction near the end of chilled storage life. The losses can be minimised by optimising on-farm production protocols to maintain a consistent colour in farmed prawns during frozen storage and by gaining additional shelf-life of chilled cooked prawns throughout the supply chain.

The opportunity is to introduce a range of technologies, along with widely-adopted proven best practise, that maintains premium quality after cooking and freezing. The technologies will incorporate natural compounds with antimicrobial/antioxidant properties, synergistic packaging, glazing and thereby extend chilled storage-life of the prawn whilst maintaining optimal quality. By maximising astaxanthin level at harvest and reducing degradation during storage, consistent premium red-orange colour of prawns will be assured for the retail market.

This research addresses the Program 3: Improving Farmed Prawn Market Value priority of APFA’s Five Year R&D Plan for the Australian Prawn Farming Industry, 2007-2012. Program 3 seeks to achieve the objective of increasing the average price received for Australian farmed prawns to $16.50/kg.

The yellowfin bream is an important commercial and recreational species in Queensland, with over 400t landed annually. Anecdotal evidence suggests that the incidence of Saddleback Syndrome (SBS), a skeletal deformity primarily affecting the development of the dorsal fin spines, is increasing. This increase in the prevalence of SBS may result in recreational fishers and the public losing confidence in catching and consuming fish afflicted with the syndrome. It is, therefore, important that objective information is available to counter these concerns.

This project addresses one of the Queensland Fisheries Research Advisory Board's Research & Development priorities for 2010. Specifically, it addresses the "urgent need for research into the cause of a particular deformity of bream that is occurring in the important Moreton Bay fishery". The Queensland Fisheries Research Advisory Board (QFRAB) recently advised that a desktop study should be undertaken to determine potential causes of SBS in the international literature. Additonally, QFRAB advised that data from DEEDI's Long Term Monitoring Program should be analysed to determine the extent of SBS in Queensland.

Mr. Tony Ham, Fisheries Queensland Manager of Recreational Fisheries, has advised that SBS is an important issue, requiring attention in order to determine the incidence and cause of the syndrome in key recreational fish species.

Further, the need to investigate the cause of saddle-back deformities in yellowfin bream in SE Qld is of major importance and concern to the recreational fishing sector according to Sunfish Queensland, the recreational fishing representative group on the inshore finfish Scientific Advisory Group (SAG).

This project also addresses the concerns of commercial net fishers in Moreton Bay, specifically through the Moreton Bay Seafood Industry Association. These concerns relate to the potential difficulties in marketing bream and other species suffering from Saddleback Syndrome considering the perceived increase in the syndrome’s prevalence in recent years.

Streptococcus agalactiae is an emerging disease in Australian fish. A challenge model in Qld groper is required to understand the pathogenesis and mode of transmission of S. agalactiae. This information is critical to determine how to manage the spread of disease and identify likely sources of infection. Information generated from this trial will be useful for finfish farmers and marine aquaria to minimise chances of infection, and for state government veterinarians to develop future biosecurity plans for control and eradication of the disease.

There are no diagnostic tests available in Australia to detect S. agalactiae in fish other than bacteriology that takes up to a week for results. Development of rapid and accurate diagnostic tools including Gold standard PCR and in situ hybridisation for S. agalactiae are urgently needed by State and private Veterinary Laboratories to enable rapid diagnosis of S. agalactiae in marine fish and elasmobranchs. Availability of these tools will have flow-on benefits for all States of Australia, allowing increased aquatic animal disease detection and will enhance current and future State surveillance and monitoring of Streptococcosis in fish. Current disease surveillance of fish at aquaculture sites within the GBRMP will be enhanced by the availability of more accurate and rapid diagnostic tools.

Different strains of S. agalactiae have been isolated from Qld gropers, wild marine fish and stingrays in north Queensland by QPIF. There is a need for the development of molecular typing tests to accurately identify different strains of S.agalactiae in order to determine origin (native or exotic) and routes of dissemination of infection, thus enabling AQIS to make informed decisions in relation to the importation of fish. Moreover, commercial vaccine companies can produce effective autogenous vaccines to protect at-risk populations of fish and elasmobranchs, benefiting commercial aquariums, marine aquaculture and research facilities by protecting valuable stock.