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Background
Implications
Regional aspects
Assessing and measuring the current situation
Indicators
Management responses
Discussion
Future directions
Recommendations
Related issues
Related case studies
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Background 
The ecology of Tasmania's coastal, estuarine and marine areas is complex, with species and communities in a state of constant flux. The ecosystems are some of the most diverse on earth and many of their member species are not found anywhere else. The diverse marine fish fauna include more than 600 species: 300 in shallow waters, 125 or more species near the continental shelf, and about 80 species in deep sea or oceanic habitats. At least 27 species of whale and dolphin use our waters on a regular basis. A phenomenal 100,000 species of marine invertebrates occur in Australian and Tasmanian waters. Apart from a few commercial species, such as lobsters, abalone and scallops, virtually nothing is known of their taxonomy, ecology, distribution and habitat requirements (State Biodiversity Committee 2002). The vast majority of these species are only found in the temperate waters of southern Australia and some species, such as Giant Kelp (Macrocystis pyrifera), are only found in Tasmania. Tasmania has a remarkably long coastline for its size because of its many islands and highly indented coastline. The resultant wide range of levels of exposure to marine conditions gives rise to a richness in ecological niches-from sheltered lagoons to wild, open coastlines. The mixing of the warm tropical water coming down the eastern Australian coast with the cool, nutrient rich waters of the Southern Ocean adds further variety. The land also profoundly influences what happens in the marine waters, especially the estuaries. For example, most of the sandy beaches are built from the sediments washed down the rivers through time, while the nutrients delivered by the rivers supply food to the marine plants and animals in the estuaries and beyond. Tasmania is distinctive in that, on occasions, a significant part of the coastal nutrient levels also comes from the cooler Southern Ocean water. This results in highly variable environmental productivity. The condition of the ecology of the coastal, estuarine and marine environments is an issue because it supports the health and well being of the people of Tasmania in innumerable ways, enhancing the value of fishing, aquaculture, recreation, transport, tourism and real estate. It also helps to define the Tasmanian sense of identity, both as an island State and an island people. In fact, over a quarter of the area of the state of Tasmania is below the high water mark. However, there is a significant lack of knowledge about the condition of the ecology of the coastal, estuarine and marine areas of Tasmania, which creates a great deal of uncertainty about how to manage human impacts. The risk of major ecological damage-such as a loss of biodiversity or the collapse of a fishery-is increased when such uncertainty exists. For example, estuaries are a prime location for human activity in Tasmania with most residential, business and industrial activity located in and around estuaries. Agricultural and forest industries can also impact on estuaries when the quality and quantity of water delivered by the rivers is reduced. Estuaries are key locations ecologically, with very high levels of species richness and acting as nursery and feeding areas for many species. However, while some limited monitoring programs are in place in a few of the largest estuaries, they mostly collect information about water and sediment quality, which, on its own, does not tell us much about the ecology of the estuaries. Understanding the ecology of the coastal, estuarine and marine environments is made challenging because of the difficulties in comprehending the sheer complexity of the relationships between species and the physical environment. Often scientific study can only measure a small subset of the relationships, in a few locations and over small periods of time whereas the interactions are often extremely complex and take place over large areas through very long periods of time.
The science of ecology has grown out of the study of natural history. Ecology uses mathematics and science to produce and test hypotheses, or models, about the interrelationships between the physical world and the plants and animals that live there. In Tasmania, there is no set of scientifically defined ecosystems or habitats (Edgar 2001). This is partly because the webs of interactions are not yet adequately understood, but also because of the dynamic nature of the environment, where species themselves move between habitats during their life cycles. In addition, seasonal and interannular variations result in constant change. The lack of ecosystem definitions means that a lower order of environmental grouping needs to be used for reporting. In this report, the concept of 'habitat' is used to represent ecological diversity. Different habitat types reflect different ecological and environmental conditions and, therefore, different components of biological diversity (Saunders et al. 1998). It is important to appreciate that, in comparison to many habitats on land, coastal and marine habitats often cover very small areas. The factors governing the ecology of the coastal, estuarine and marine environments - such as nutrients, light levels, salinity, wind and wave exposure and bottom type - have created 'bands' of different living systems along the coast. For example, seagrasses typically only occur in waters between high water mark and 20 metres deep. The strong linear zonation of these environments means that many species are restricted to long narrow bands that are both highly vulnerable to local impacts and tend to give a false impression of the overall extent of some species. For example, Giant Kelp (Macrocystis pyrifera) may seem to be abundant around south-eastern Tasmania but a recent estimate of its total extent is about 770 ha, or 7 km2. This SoE report loosely distinguishes between coastal, estuarine and marine habitats but there is a great deal of overlap in reality. 'Coastal' refers mainly to the immediate nearshore area including the intertidal zone and the dry land immediately adjacent, while 'marine' refers to the areas further offshore that are mostly influenced by the sea. 'Estuarine' refers to the sheltered waterways where freshwater and marine waters interchange. The nature of the 'coastal zone' makes it difficult to set it apart from the land or the atmosphere and many aspects of the environment cross the arbitrary boundaries made between them. It is because of this that many issues identified in the coastal zone are covered in other parts of the report. For example, plant biodiversity-incorporating coastal plants-is covered in the Inland Waters and Wetlands. Coastal, estuarine and marine habitat types
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Prevailing influence |
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Habitat |
Example |
Coastal |
Estuarine |
Marine |
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Supratidal |
Saltmarsh |
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** |
** |
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Offshore islands |
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** |
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Intertidal |
Rocky shore |
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** |
** |
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Sandy shore |
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** |
** |
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Mudflat |
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** |
** |
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Subtidal |
Rocky reef |
algae or sponge |
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** |
** |
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Unconsolidated substrate (Vegetated) |
seagrass,
Caulerpa |
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** |
** |
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Unconsolidated substrate (Unvegetated) |
hard sand to silt |
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** |
** |
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Unconsolidated substrate (Light Sponge) |
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** |
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Seamounts |
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** |
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Source: Partially adapted from Edgar 2001
Implications Various industries are dependent on a high quality coastal and marine environment. For example:- marine farming is worth about $100 million a year and is one of the States most significant industries;
- commercial wild fishing is worth $160 million a year to the State's fishers. There are about 850 commercial fishing boats involved and the industry employs around 2,000 people, including processors.
Examples of ecological changes that have implications for these industries include:- toxic dinoflagellate blooms (impact on shellfish farming);
- moon jellyfish swarms (impact on salmon marine farming);
- increase in sea urchin 'barrens' (impacts on rock lobster and abalone fishing);
- reduced water flows and changed patterns in flooding can impact on estuarine productivity;
- reduced water quality (impacts on all sectors, particularly aquaculture); and
- introduced species, such as Northern Pacific seastar (impact on shellfish farming).
Besides potential losses to industry, negative changes in ecological condition can have serious implications for deeply held cultural activities as simple as taking the children for a holiday to the beach as well as impacting on tourism marketing strategies, particularly in regional centres. In addition, ecological changes can result in serious losses of both biodiversity and natural 'services', such as effective sewage waste disposal. There have been attempts at valuing the services provided by ecosystems to the economy. For example, Costanza et. al. (1997) estimated the economic value of 17 ecosystem services for 16 biomes, or habitats. The values indicate that natural coastal environments, particularly those in estuaries, are easily among the most valuable on earth. Value of ecosystem services 1994 US$ per hectare per year
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Biome (habitat) |
Value (1994 US$) |
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Open ocean |
252 |
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Estuaries |
22,832 |
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Seagrass/algae beds |
19,002 |
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Continental shelf |
1,610 |
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Temperate forests |
302 |
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Grass/rangelands |
232 |
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Tidal marshes/mangroves |
9,990 |
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Swamps and floodplains |
19,580 |
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Lakes and rivers |
8,498 |
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Cropland |
92 |
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Source: Costanza & Folke 1997
Regional aspects The issue of the ecological condition of coastal, estuarine and marine habitats is relevant to whole of the coastal zone including the foreshore. The interrelationships between the species and the environmental processes cross the land-water boundary and extend to the deepest State Coastal Waters. Estuaries should be recognised as among the areas of greatest natural ecological change and greatest human impacts. Assessing and measuring the current situation There are some monitoring programs in place-such as Marine Farm monitoring-but they are mostly very targeted to a particular issue. Even when grouped together, they produce an unclear picture of the health of Tasmania's coastal, estuarine and marine ecosystems. There is, in particular, no ongoing Statewide assessment of the biological components, and their interaction with each other, and the physical environment. Improved efforts are developing around the assessment of ecological sustainability for export fisheries, but these assessments are largely limited to the sustainability of the fishery itself rather than the impact of the fishery on the supporting ecological systems (apart from monitoring by-catch and interactions with threatened species). The following sets out the statutory requirements for monitoring, and some additional programs, relevant to the ecological condition of coastal, estuarine and marine habitats. - The State Coastal Policy 1996 sets out a statutory requirement for monitoring but, other than a report on the coastal zone in the SoE report (ie this report), there is no requirement to report any particular matters to any specific timetable. However, all Coasts and Clean Seas funding applications and Marine Farm Development Plans are assessed against the State Coastal Policy, including the following outcomes (Outcome 1.1.6 and 4.4):
- Appropriate monitoring programs and environmental studies will be conducted to improve knowledge, ensure guidelines and standards are met, deal with contaminants or introduced species and generally ensure sustainability of coastal ecosystems and processes and ensure that human health is not threatened.
- The effectiveness of the State Coastal Policy will be monitored and assessed throughout its term. A report on the coastal zone will be included in all State of the Environment Reports which the Resource Planning and Development Commission submits to the Minister pursuant to Section 29 of the State Policies and Projects Act 1993.
- The Living Marine Resources Management Act 1995 and the Marine Farming Planning Act 1995 require monitoring of environmental conditions under and around marine farms as specified in the Marine Farm Development plans and each individual license. The data are reported to the Marine Resources Division of DPIWE and a report covering 1997-2002 is almost ready for release. Broader environmental monitoring of the effects of marine farming is being developed by the CSIRO and TAFI. For example, the Huon River Study is completed, and now the D'Entrecasteaux Channel Study has begun. These studies include the development of physical and chemical models to help understand the whole system. Intertidal, seagrass and jellyfish monitoring techniques are also under development.
- Since 1999, Environment Australia requires assessments of the ecologically sustainability of wild export fisheries, such as abalone and rock lobster under the Environment Protection and Biodiversity Conservation Act 1999.
- Public Health Act 1997 and the Food Act 1998: Tasmanian Shellfish Quality Assurance Program assesses contaminants and dinoflagellates.
- Since 1999, TAFI has implemented a program called Seamap Tasmania that is mapping the distribution of seafloor habitat types in estuarine, coastal and marine waters of Tasmania through photographic, acoustic, biological and sediment sampling. Maps, video and images are published, or updated, as they become available.
- The Marine Protected Areas are the subject of episodic monitoring studies into their ecological condition by marine researchers subject to funding.
Indicators
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Land Cover - at a glance
- Catchments in the south-west and west of the State indicate a relative pristine condition evidenced by little woody vegetation change over the period ~1994-2001. These catchments include: Port Davey, Wanderer-Giblin, and Gordon-Franklin.
- Other catchments have experienced little woody vegetation loss because their land cover has already has been substantially altered to pasture, agriculture or urban.
- Catchments with the highest percentage of their areas subject to woody vegetation decrease are in the north-west of the State. These decreases are due to forest harvesting in upper catchments and agricultural activity in middle and lower sections. These catchments are the Emu, Cam, Leven, Blythe, Mersey and Forth Wilmot.
- The Little Forester River has the highest percentage of catchments in the north-east of the State subject to woody vegetation decrease in the period 1994-2001. The headwaters of this catchment include areas cleared for extensive plantation development around Scottsdale. In the south-east of the State, the Tasman catchment has the highest percentage of its area subject to woody vegetation decrease between 1994-2001.
- Catchments may also be assessed in terms of land cover and the percentage of catchment area under modified land cover classes. The modified land cover classes include more intensive land cover classes identified through the 2001 land cover classification of Tasmania: pasture, agriculture, urban, suburban, bare land, and forest activity.
- Catchments in the south-west and west of the State indicate a relatively pristine condition evidenced by less of their catchment areas under 'modified' land cover classes. These catchments include Port Davey, Wanderer-Giblin, and Gordon-Franklin. A number of east coast catchments have maintained relatively high percentage catchment areas under 'natural' land cover (less than 20% modified): George, Swan-Apsley and Prosser. In the south-east, the Huon catchment also maintains a relatively high percentage of natural land cover.
- A number of catchments ranked poorly both in terms of a high percentage of their areas experiencing woody vegetation change and a high percentage of their areas being under modified land cover classes. These catchments were the Cam, Inglis, Blythe, Rubicon, Leven, Montagu and King Island. Twenty catchments in Tasmania exceed the minimum level of native vegetation retention of 30% suggested by Williams (2000). A further six catchments are approaching this figure of 30%: Little Swanport; Black-Detention; Derwent Estuary-Bruny; Pipers; Furneaux; and Great Forester-Brid.
- Urban and suburban uses represent a substantial modification of land cover with significant flow-on impacts for catchment condition. The five catchments with the highest percentage of their area under urban and suburban land uses are Lower Derwent, Derwent Estuary-Bruny, Cam, Tamar Estuary, and North Esk.
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Management responses - Since 1999, Environment Australia requires assessments of the ecological sustainability of wild export fisheries, such as abalone and rock lobster under the Environment Protection and Biodiversity Conservation Act 1999. Accreditation documentation is developed for the Tasmanian Giant Crab, Rock Lobster and Abalone fisheries. The Rock Lobster fishery was accredited in 2002 and the Giant Crab and Abalone fisheries are proceeding through the accreditation process (Ford 2001; Levitt 2002).
- Parks and Wildlife Management Plans for 88 offshore islands are drafted and undergoing the approval process. The existing tenures of the islands are very mixed including Nature Reserve, National Park, Game Reserve, State Reserve, Conservation Area and Unallocated Crown Land. Management Plans will provide a significantly higher level of control over activities on the islands. Further information can be obtained from the IslandCare.
- Twenty-three of the 24 coastal councils (excluding Flinders) have participated with the State Government and other stakeholders in the development of regional coastal and marine management strategies around Tasmania and are now implementing the priority actions. The regions and the councils involved are:
- West North West - West Coast, Circular Head, Waratah/Wynyard, Burnie, Central Coast, King Island, Latrobe, Devonport
- Tamar - West Tamar, Launceston, George Town
- East North East - Dorset, Break O'Day, Glamorgan/Spring Bay
- South East - Tasman, Sorell, Clarence
- Derwent Estuary Program - Hobart, Glenorchy, Clarence, Brighton, New Norfolk, Kingborough
- D'Entrecasteaux Channel - Kingborough, Huon Valley
- The Seamap Tasmania habitat mapping program is producing high quality maps, supported by high quality images and video.
- In support of sustainable management, marine farm intertidal zone monitoring techniques are under development through the efforts of industry, and researchers at TAFI and CSIRO, partially under the auspices of the FinFish Cooperative Research Centre (CRC).
Discussion - Tasmania has high levels of biodiversity, much of it found only here. The richness of the biodiversity owes much to the complex coastline, offshore islands and the convergence of oceanic currents - all of which provide a wide range of environments and ecological niches.
- No trend analysis is possible for ecological condition because the bulk of the available data are about the extent of habitats rather than condition. Where condition is reported, it is in a limited way and usually only once so, again, trend information is not available. However, studies within the few Marine Protected Areas are contributing significantly to ecological understanding.
- Good progress has been made in understanding the state of the estuaries. Estuaries are a key location for human activities in Tasmania and, while progress is being made on improving water quality, the ecology remains heavily impacted from actions over the last 100 to 200 years. It is clear that one of the main impacts on estuarine ecology is through siltation. Unfortunately, evidence of catastrophic loss of species in estuaries over the last two centuries is emerging from recent work based on dating long sediment cores taken in estuary sediments.
- There are some monitoring programs in place for water and sediment quality in some of the major estuaries but there are no programs measuring the biological components and relationships.
- Good progress is being made in mapping the extent of coastal, estuarine and marine habitats, however, this is not the same as identifying the extent of ecosystems. Further developmental work is needed to make the step from habitats to ecosystems.
- Results of monitoring the Maria Island Marine Protected Area strongly suggest that fishing significantly impacts the ecology of many of the Tasmanian marine reef environments outside of the Marine Protected Areas.
Future directions - Conduct monitoring of the ecological condition of Tasmania's coastal systems, including reefs and estuaries, particularly including the biological elements.
- Extend Statewide the collection of detailed habitat mapping of marine and estuarine environments to the standard set by the Seamap Tasmania program.
- Extend the biodiversity assessment of the saltmarsh and intertidal zone to the western part of the state, including invertebrate studies similar to those of Wong et al. 1993, Richardson et. al. (Richardson et al. 1996 and Richardson et al. 1997).
- Extend the mapping and condition assessment of Tasmania's foreshore to the standard set by the Integrated South East Coastal Management Strategy (Reserve Design and Management 2002).
- Extend the requirements for reporting on ecological sustainability to all Tasmanian fisheries.
- Cooperatively engage with the Commonwealth in the management of the marine areas surrounding Tasmania, including the setting of marine boundaries related to fisheries management and Marine Protected areas.
- Further work is needed to establish the freshwater requirements of estuarine ecosystems. Questions remain about not only how much freshwater is needed to maintain ecosystem health, but also about when and how big the flows should be. For example, floods are large events that strongly impact on estuaries - how big do they need to be to ensure the integrity of the estuaries so they can continue to provide high quality environmental services.
Tasmania Together and the RMPS Relevant Tasmania Together goals and standards for 'Coastal, Estuarine and Marine' are listed in the linked file. The Tasmania Together Progress Board reported on progress toward targets for benchmarks set (Tasmania Together Progress Board 2003). Indicators, targets and baseline data are available in the latest Progress Report June 2003. Further information, including progress report updates, is available from Tasmania Together. Involvement of the community, and the fair and orderly use of resources are also fundamental principles of the RMPS. The RMPS objectives have been developed to advance the principles of sustainable development. Recommendations
Related issues
Related case studies
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