The project is essential for four main reasons. First, experience in other countries, now rapidly developing new species like Atlantic cod, turbot, haddock and halibut, indicates the need for a new coldwater species to complement the existing salmon industry in Australia, which is facing significant challenges (see Background B2). Major stakeholders, the Tasmanian Government and Tasmanian Salmonid Growers Association fully support the development of striped trumpeter as an alternative species, recognising that it is a long-term investment (Appendix 3 and 4). The Tasmanian Aquaculture RAG and TasFRAB have sanctioned the project as a top priority. Overcoming the striped trumpeter larval mortality bottleneck is identified in the Tasmanian Fisheries and Aquaculture Strategic Research Plan 2005-2009 as a high priority. Second, the project addresses the two objectives of the Aquafin CRC, Production Subprogram (Subprogram Hatchery Technology) by increasing the availability of species suitable for aquaculture and improving the quality of fingerlings for farm stocking. It also potentially fills an expertise gap for the CRC following the Tuna Propagation Program demise by further developing a team capable of tackling difficult to rear marine fish and tapping into research institution in-kind contributions. The Aquafin CRC Board and JMAC has requested the submission of the proposal. Third, there is an identified need for the research at a generic level where there is a necessity for both, a more systematic way to match the nutritional profile of live feeds with the requirements of new species of marine larvae (FRDC Hatchery Feeds R&D Plan high priority), and the development of system design and probiotics for the control of disease or improved health of hatchery and farmed aquatic animals (key area for research (7.2.2) in the Aquatic Animal Health Subprogram Strategic R&D Plan 2002-2007). Fourth, it facilitates capacity building and collaboration among the key institutions developing new marine species and an excellent training opportunity for post-graduate students, hatchery technicians and scientists.

Validate a sensitive and specific Nested RT-PCR test.

- There is a need to ensure the Nested RT-PCR test developed at OVL will detect the range of endemic nodaviruses from a variety of finfish species. It is also important to ensure the test will detect exotic nodavirus isolates for use in the event of an exotic nodavirus incursion.
- Standardisation of reagents and sample collection and preservation protocols will enable consistency of test methods between laboratories.
- A test is required to screen broodstock samples to eliminate nodavirus-positive carrier fish from production facilities. Due to the small sample sizes obtainable, the Nested RT-PCR test is the best test option.

Establishment of a cell line.

- Cell culture is considered the gold standard for virus detection. The cell culture will enable cost-effective screening of larvae for sale or release and to develop management procedures.
- Cell culture is more tolerant to sample degradation than other detection methods and allows testing of material that is unsuitable for use in other tests.
- The vast majority of cell lines currently available have been produced from temperate species. Availability of cell lines, from tropical fish species, is required.

Immunodiagnostics

- FAT tests can confirm the identity of viruses isolated in cell culture during diagnostic or surveillance activities. Their use is critical for the identification of viruses.
- Immunohistochemistry/immunofluorescence is a sensitive and specific test that can be used on fixed material. It is not always possible to obtain fresh samples and confirmation of nodavirus in tissue sections can be required. Immunohistochemistry is also a tool to identify the tissues targeted by nodavirus.

In the financial year 1997/98 all Tasmanian fin fish farms experienced increased levels of seal interaction resulting in tangible losses of around $1.5 million. 164 seals were trapped and relocated in 1996/97 compared with 37 the year before and 10 when this form of management was first introduced. In response to the increase in interactions, the industry spent an estimated $ 1 million on upgrading predator nets over the last financial year. Licensed shooting, trapping and relocation of seals have been used by the industry, in conjunction with the Department of Environment and Land Management, in previous years, but these methods are not considered to be either acceptable (because of risk of spreading disease, animal ethics concerns and fishery management issues), or cost effective.

The Tasmanian Atlantic Salmon industry is set to expand substantially in the short to medium term, with production projected to double within 5 years. With this expansion, new areas, both near shore and off shore will be developed for marine farming. Seal predation will be at least, if not more significant in these areas. The development of some aquaculture projects in other states, notably Western Australia, has been postponed due to perceived potential problems with seals, and the inadequacies in current stock protection systems.

The Southern Bluefin Tuna farming industry in South Australia, while relatively new already suffers large losses due to predation by sharks and seals. Losses due to predation by sharks and seals have a substantial impact on the industry, with annual direct losses estimated at $1.2 million and growing rapidly. Existing predator deterrent methods have not proven to be effective for the farming or towing conditions experienced by the industry. This project will contribute directly to the tuna industry by providing reviews of predator systems and designs of new nets to restrict predators affects on farms.