Following many expressions of public concern regarding the potential for finfish/tuna aquaculture to attract sharks to coastal areas, at both regional development and individual site applications, PIRSA Fisheries and Aquaculture identified the need for an understanding of the factors that may explain associations between sharks and finfish/tuna aquaculture activities. This view was reinforced at meetings of the AAC (including a presentation from the PI on 22 Feb 2013), who are a legislated body under the Aquaculture Act 2001, advising the State Minister for Agriculture, Food and Fisheries on matters relating to aquaculture development. As a consequence, this project was listed as a priority area for investment by the SAFRAB.

A previous FRDC funded workshop (2002/040) identified a need to understand factors that may explain interactions between pelagic sharks and aquaculture activities. Some of the findings highlighted during this workshop are now considered to be outdated. For example, anecdotal accounts from finfish farmers and commercial fishers suggest that white sharks sightings have increased in the past decade in Spencer Gulf and this may have implications for the frequency of interactions with the fishing and aquaculture industry. The provision of data to further inform the public’s current perception of the aquaculture industry represents a key priority in South Australia’s Fisheries and Aquaculture R&D Strategy. During the development of this project the need for this research was discussed with key industry representatives.
This proposal addresses key objectives of the Draft White Shark Recovery Plan, 2010 (2c, 7a, 9a and 9b).

This is the first time that an illness associated with Vibrio has been traced-back to Tasmanian oysters. Regrettably, this incident occurred in the only major harvesting area in Tasmania that has not been impacted by the current Pacific oyster mortality event.

In Australia the control of Vibrio is currently limited to temperature controls during storage or transport. Pre-harvest controls used by the shellfish quality assurance programs are predicated on controlling risk posed by faecal contamination and biotoxins and are not suitable for controlling risk from these naturally occurring bacteria. Although the recent implementation of the Codex Standard for pathogenic marine vibrios suggests risk in bivalve growing areas should be assessed to ascertain the risk to public health, there has been limited research undertaken in Australia. The studies undertaken to date have generally been short in nature with no comprehensive longitudinal studies being undertaken and methodologies have now progressed significantly, whereas New Zealand has been undertaking a long-term survey to understand the risk posed by these pathogens (Cruz, Hedderley & Fletcher 2015). This issue may become a risk in accessing key markets that are active in monitoring or who regulate for these pathogens.

There is an immediate need to collect information on prevalence for the remainder of the summer period to understand the risk and evaluate if there is a relationship to salinity, temperature and toxic strains. This information will be immediately useful for developing appropriate management plans in this growing region.

This illness outbreak will likely result in Tasmanian Shellfish Quality Assurance Program and the other state programs having to consider how to manage risk in the growing areas and establish what is an acceptable level. The work proposed here could be used as a framework for future work that assesses risk across the bivalve industry Australia-wide.