Development of a national biotoxin strategy
Department of Primary Industries and Regions South Australia (PIRSA)
Principal Investigator: Kirsten Todd
Key Words: Biotoxins; shellfish; microalgae; international standard; public health; monitoring; algae
In Australia, as in many countries, aquaculture and wild harvest of shellfish is an economically important and growing industry. The safety of these products as a food source is of utmost importance from both public health and economic points of view. One of the potential problems faced by shellfish growers is the contamination of their product with marine biotoxins. These are chemical compounds (toxins) that are produced by specific naturally occurring marine microalgae. Most microalgae (a.k.a. phytoplankton) are actually an important food source of the shellfish. These biotoxins can induce human illness if contaminated shellfish are consumed. This is not only a problem for commercially produced or harvested shellfish; it is also a problem for recreational shellfish gatherers, for some of which this may be subsistence gathering.
Biotoxins are not only a problem for Australia, as most coastal countries in the world have had, or have the potential for, problems with marine biotoxin contamination in shellfish. In order to manage this problem, many countries have monitoring programs aimed at the detection of the species of microalgae that produce the toxins, and for the toxins themselves in the shellfish. Monitoring for the microalgae is a faster and cheaper test than shellfish testing, and may give an early warning of the potential for contamination of shellfish with marine biotoxins. However, the two types of testing need to be performed in conjunction with each other. Internationally, food safety regulations are based on the levels of toxins in shellfish, and it is these results that should generally be used for regulatory decisions. It is a common misconception that cooking or processing the shellfish in some way will remove the toxins and make the shellfish safe to eat, in some instances the toxin compounds can be converted into more toxic compounds by cooking.
Internationally the impacts of toxic microalgae on both public health and the economy are increasing in frequency, intensity and geographic distribution. As aquaculture expands, and its importance as both food and income sources increases for many countries, it is expected that these impacts will also increase. As international markets become more conscious of the safety of the foodstuffs they import, they impose safety regulations and can impose non-trade barriers.
Australia’s shellfish industry’s market has a large domestic component, with shellfish landings worth approximately $90M per year. There is, perhaps, less external pressure on Australia to manage these problems. However the domestic market is large, and the consumers no less important than overseas consumers, and hence there remains the need for protection from marine biotoxins. There need to be controls in place between states, just as there need to be controls for exporting product. The USA has a similar political structure to Australia, with both state and national governments, and in order to protect the public health of shellfish consumers in other states, a model ordinance was implemented which all states must ratify to ensure meeting the standards set out in this document. This document is a voluntary agreement between states, and spells out the acceptable monitoring programs, controls and regulations that must be met in order to ‘export’ shellfish to another signatory state. This model ordinance is fairly well accepted as an international standard for shellfish safety, along with the European Union directives, which must be met in order to export shellfish to the EU.
This report summarises the available information on:
This report is in two part: Part A - A Review of Marine Biotoxin Management in Australia; and Part B - A Model Australian Marine Biotoxin Management Plan.
Currently Australia has no national guidance on marine biotoxin monitoring, although there are programs conducted in most states to varying degrees. One of the difficulties in implementation of a national strategy has been the lack of reliable information on and knowledge about the history of the occurrence of toxic microalgae and marine biotoxins in some shellfish growing areas. This project has involved a review of the monitoring programs and the history of potentially toxic microalgae for all the states. Victoria, Tasmania, South Australia and New South Wales have already experienced closures or human illness due to marine biotoxins. New Zealand has detected all temperate biotoxin producing microalgal genera, and has also found most of the tropical genera in the sub-tropical northern regions. The Australian coastline encompasses all climate zones and it is expected that all biotoxin producing species will be detected over time, and that they will bloom as conditions become favourable to them.
There is currently a lack of consistency in marine biotoxin management between the states, which must be addressed. For a national marine biotoxin strategy to succeed there needs to be commitment from all states to participate in and meet the requirements of the program.
One of the key aspects in successful monitoring programs is having ongoing research underpinning the program. There needs to be more investigation of the microalgae species that are present in Australian waters, including culturing them and testing for toxin production. It is only after this work is undertaken that action levels relevant to Australia can be set. In the meantime, action levels are based on international experience, and may not necessarily fit the Australian situation. Other important research that will strengthen monitoring programs is the investigation of the uptake, retention and biotransformation of toxins in shellfish; some species take up toxins more quickly, some depurate toxins more quickly, and some bio-transform toxins into different (and potentially more toxic) compounds. This research is on going internationally, and as more research is done, more questions are asked. Federal funding (eg Fisheries Research Development Corporation or Australia Research Council) is required for many of these research questions.
The funding of a monitoring program, however, is not the responsibility of such agencies. The costs of programs need to be shared by all users, which enhances the coverage of monitoring information, and reduces the direct cost for the industry. Internationally, shellfish safety tends to be managed by either Health or Fisheries Departments, however in Australia, the situation varies between states. There needs to be commitment and support from both State and Federal governments, and in particular between fisheries and health agencies, but not excluding Environmental Protection Agencies, Sewage Authorities, Port Authorities, Aboriginal Commissions, and other stakeholders. Countries such as Canada, USA and New Zealand invest approximately 1-2% of the value of the industry in biotoxin monitoring. Currently Australia invests approximately 0.02% in biotoxin monitoring.
There needs to be the open sharing of data between all players in the monitoring, and this includes researchers. If there is a sharing of cost, then there also tends to be a sharing of information. One of the positive outcomes of this is that research can become targeted towards the real issues that the shellfish industry faces. In order to achieve this goal of openness, there need to be clear channels of communication, and roles and responsibilities clearly delineated. There also needs to be on going education of the industry, regulators and policy makers.
A marine biotoxin monitoring program is a long-term commitment to protecting the public health of shellfish consumers, understanding more about the shellfish resource and assisting the industry to growing into the future. It requires regulatory commitment at Federal and State government level to maintain and police biotoxin standards.
1. To design a national biotoxin monitoring strategy, in consultation with government and industry, which provides an appropriate level of protection to the seafood industry and the consumer, against biotoxin contamination.
2. To assess the implications for public health from marine biotoxins.
3. To identify those organisms that pose a biotoxin threat to marine and estuarine shellfish in Australasian waters, and identify those Australian industries at risk.
4. To review existing biotoxin monitoring programs, phytoplankton surveillance, analytical expertise and recognition of program deficiencies.
5. To identify internationally recognised practices for the management of marine biotoxins in shellfish.
6. To identify gaps in current methodology for the identification and measurement of relevant biotoxins.
7. To determine a suitable protocol for consolidation, collation and analysis of data on biotoxins to support the development of predictive and management tools.