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At a glance 
The issue Globally invasive marine species have been identified by the International Maritime Organisation as one of the four greatest threats to the world's oceans because of their impacts on the environment, economy and public amenity. More than 250 introduced marine organisms have established in Australian waters since European settlement and the threat of new introductions is constant. As trade with other countries grows, so too does the risk that exotic marine organisms will be introduced through ballast water discharge and hull fouling. Not all introduced marine species become pests. In Tasmania there are 10 introduced species that are recognised pests on the Australian ballast water target species list. Most non-native marine organisms in the State were probably introduced by international shipping. Ballast water discharge and hull fouling are thought to have been responsible for transporting 26% and 40% of introduced species into Tasmanian coastal waters respectively (Thresher et al. 1999). Marine pests can impact on the State's valuable aquaculture industry. For example, blooms of the introduced toxic dinoflagellate (Gymnodinium catenatum) can cause high levels of toxins to build up in commercial mussels and oysters, causing temporary closures of marine farms. Baseline surveys are undertaken to determine the extent of the marine pests problem. However, they are extremely expensive because they take a long time to complete, require a large amount of fieldwork, and require identification of species by expert taxonomists. This 'At a Glance' section provides an overview of the marine pests and diseases issue. More detailed information and references are available in the Marine Pests and Diseases Issue Report. This includes information on the current extent and distribution of marine pests and diseases in Tasmania. A recommendation is presented on Managing Marine Pests and Diseases. Favourable news- Since the last SoE Report (1997) there has been a National Taskforce report which addressed the issue of introduced marine pests in Australia (SCC/SCFA 2000). This report, which was endorsed by three ministerial councils, makes recommendations for the prevention and management of introduced marine pests. This has led to a more coordinated approach to the problem nationally.
- Mandatory ballast water regulations were introduced by the Australian Quarantine and Inspection Service (AQIS) in 2001. These require the majority of international vessels to exchange their ballast en route to Australia. This has greatly reduced the risk of marine pests and diseases being introduced to Tasmania via ballast water discharge. AQIS has developed a Decision Support System to assess the risk posed by ballast water from individual ships.
- The CSIRO Centre for Research on Introduced Marine Pests has developed baseline port survey protocols for introduced and cryptogenic (i.e. uncertain invasion status) species (Hewitt and Martin 2001).
- The DPIWE has completed baseline port surveys of all first ports of call and other high risk ports/marinas in Tasmania to determine the distribution and abundance of introduced marine species. Surveys were completed in the ports of Launceston, Hobart, and Triabunna (A. Morris pers. comm.). Surveys of all other major ports in the State, and six minor ports/marinas, are currently being organised by the DPIWE and the relevant authorities through a Natural Heritage Trust Strategic Package project. The DPIWE is working with the ports to establish longer-term monitoring programs to maintain the currency of the port survey data and increase early warning capabilities.
- Education programs have been conducted to raise awareness, and to inform the public what boat owners, amateur aquarists and fishers can do to prevent the spread of marine pests. A marine pest section was included in the current 'General Sea Fishing Rules' (2002), which is distributed to all recreational fishing licence holders. Education programs are also conducted in association with the baseline surveys of the Ports of Launceston and Hobart.
- The Tasmanian Marine Farm Monitoring Project was set up as a trial program between 1998-1999 to raise awareness of marine pest issues in the Marine Farming Sector in south-east Tasmania. It also successfully assessed the potential for involving marine farmers in the early detection of marine pest incursion.
- An Introduced Marine Pest Emergency Response Plan was developed to provide a protocol in the event of new introductions.
Unfavourable news- Tasmania has a significant marine pest problem with 58 species such as the Northern Pacific seastar, Japanese kelp, and a toxic dinoflagellate invading our waters. As an indication of the extent of the problem in Tasmania, authorities in the Port of Hastings (Victoria) and New Zealand have declared that ballast water from Tasmania is very high risk. These ports do not allow ships to discharge ballast water originating from Tasmania in their waters. The Victorian Government is now considering extending this restriction to ban the discharge of Tasmanian ballast water in all Victorian ports.
- Recent Tasmanian ecological studies have indicated that some marine pests exclude native species through increased competition and predation (e.g. Mackinnon 1997 and Ross 2001).
Uncertain news- Because of a lack of baseline data, the impacts of many marine pests and diseases are difficult to prove. For example dense beds of the Japanese kelp (Undaria pinnatifida) probably cause a decreased abundance of native macro-algae by competing with them for space. However, without baseline data on the abundance and diversity of the native macro-algae before the pest was introduced, there is no way of measuring this impact.
- There are significant gaps in knowledge of the distribution of marine pests in the State. The full extent of marine invasions in Tasmania will not be known until baseline surveys have been completed. In particular, there is little information on the distribution and abundance of introduced marine species in more remote areas of the State such as King Island, the west coast and Macquarie Island.
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