In recent years there have been extensive blooms of the blue-green alga Nodularia spumigena, prompting advisories regarding the sale and consumption of fish and shellfish. In 2011-12 these advisories lasted up to 6 months in order to protect human health from consumption of contaminated seafood, and led to large economic losses to the commercial fishery and tourism in the region. The inability to accurately predict occurrence of blooms and closures before they occur, are detrimental to businesses in the region.
The increased occurrence of N. spumigena in the Gippsland Lakes has also led to increasing stress on government agencies responsible for protecting public health and providing timely, accurate information to citizens, policymakers and local businesses. Increased monitoring during blooms has significantly raised costs; with agencies under pressure to act on limited information and funding.
Black bream currently act as a sentinel species to provide early warning. However there is no information on the elimination of nodularin in this species or other key species. These are needed to provide better focus and economy to monitoring efforts. Regulatory sampling could benefit greatly if toxin elimination kinetics were known so that temporal sampling regimes could be designed and further confidence provided surrounding advisories and parts of the fish that remain marketable during blooms.
The lack of understanding of nodularin elimination and tissue distribution in fish from the Gippsland Lakes are significant stumbling blocks to the provision of management strategies to deal with seafood contamination during blooms. Clearly, there is a strong need for strategies that will enable local-, and state agencies to work together in developing early warning systems to detect and monitor seafood contamination and potential closures, which makes it possible to develop realistic mitigation strategies that minimize the risks to human health and reduce the economic impacts to government and industry.
• Develop and implement a comprehensive response plan that is based on internationally respected risk assessment principles and a scientifically sound management framework.
• Develop an appropriate cost sharing agreement so as funding will be available each year in the event of a bloom. Funding needs to be available to be deployed for sampling and toxin analysis.
• Undertake further research into uptake, tissue distribution and elimination of nodularin under field conditions in a greater number of finfish species of commercial and recreational significance to better understand risks and select an appropriate sentinel species
• Undertake further laboratory and field assessment for other toxins to fully evaluate food safety risks.
• Investigate other methods which could help in monitoring of toxins during blooms