Controlling flukes of YTK is a major cost for producers, and the industry has identified improving the treatment of flukes as one of the top research priorities. Currently, the industry bathes fluke-infested YTK in hydrogen peroxide. Although this approach is currently efficacious, it is also costly, labour-intensive, and stressful for fish. An option to reduce the need to bathe frequently is to use in-feed therapeutic agents to kill or remove flukes. This project aims to develop palatable feeds containing medications that will significantly reduce burdens of flukes.

Changing bio-fouled nets is another costly practice for the industry. Antifoulants have the potential to not only reduce the frequency and cost of net-changing due to the need to maintain good water flow bringing dissolved oxygen to the caged fish, but also to potentially reduce the numbers of fluke eggs entangling on the nets, and therefore further reduce the numbers of infective fluke larvae settling on YTK within cages. The optimum compound to use from an assessment of three will be identified.

Commercial YTK may have experienced slower growth at Fitzgerald Bay than at Arno Bay; the cause is suspected to be due the higher salinity (39-42 ppt at Fitzgerald Bay, compared with 37 ppt at Arno Bay). It needs to be confirmed experimentally whether increased salinity slows growth, first in summer and, if not, then in winter.

Health issues affecting hatchery-reared, larval SBT are presently unknown. Before production begins, the development of health protocols and a surveillance program is required, as well as the collection of archival samples of larvae for future investigations. These investigations not only ensure the biosecurity of the hatchery but also the sea-based growout stage, whether associated with hatchery-produced or wild-caught stock. This project will also allocate a small amount of funds for early disease testing, if required.

Provisions of the Commonwealth Environment and Biodiversity Conservation Act require strategic assessment and, if necessary, mitigation of the ecological effects of fishing, including trophic impacts.

The strategic assessment of the South Australian pilchard fishery identified the need to measure and minimize the impacts of the fishery
on the “broader ecosystem” and “to review the current ecological management objectives, management strategies and performance indicators”.

However, operational ecological performance indicators and mitigating strategies have not yet been established for any pelagic fishery in Australia, and there is no agreed scientific framework for establishing these tools.

In recognition of -
1) the high profile of the SA pilchard fishery (as Australia’s largest pelagic fishery);
2) the important ecological role of pilchards in the Flinders Current Ecosystem;
3) the high economic value and conservation significance of the region’s marine predators;
4) and the sophisticated (single-species) stock assessment procedures and management arrangements that have been established,
members of the South Australian pilchard fishery have identified the need to establish “world’s best practices” for managing the potential ecological impacts of the fishery. In response to this need, fishers have invested $620K to assess the role of pilchards in the Flinders Current Ecosystem and to begin to develop ecological performance indicators and reference points for their fishery.

Currently, there is no scientific framework to assess whether the management arrangements that have been established for the SA Pilchard Fishery are sufficiently conservative to ensure that fishery is managed according to the principles of ESD (i.e. that fishing does not significantly affect the status of other components of the ecosystem, Fletcher et al. 2002).

In recognition of the large data sets and extended timeframes that are needed to establish and assess ecological performance indicators and reference points for pelagic fisheries, members of the South Australian pilchard fishery have also agreed to invest a further $310K (cash) to support the additional ecological research that is outlined in this proposal.

This project addresses the pressing need to develop a scientific framework for establishing ecological performance indicators and reference points for pelagic fisheries. The focus on the SA pilchard fishery is necessary, as such a large and complex undertaking could only be contemplated in large and valuable fishery that has sophisticated stock assessment procedures and management arrangements in place, and can thus afford to allocate significant resources to support the establishment of an ecosystem-based management system.

This project is needed to refine the management plan for Australia’s largest fishery to include ecological perfomance indicators and reference points and to ensure that research and management systems for the fishery correspond with, or exceed, world’s best practice by incorporating scientifically-based approaches for assessing and, if necessary, mitigating, the fishery's potential trophic impacts.

Projects such as this are needed to maintain Australia’s position as the world leader in the ecosystem-based management of fisheries.