A national mangrove conservation strategy would need to contain objectives to cover the broad suite of activities required to maintain mangrove diversity at national, regional and local levels. The following objectives have been devised to meet this requirement.
A key element of the strategy would be to increase our knowledge base and understanding of Australia’s mangroves. The strategy must provide the framework for the collection and collation of standardised information sets on both the biological system through biological surveys, but also of the abiotic variables that control and maintain mangrove systems. A national mangrove data and information plan will need to capture existing information and in addition provide a useable and useful structure for standardised data collection and mechanisms for access and sharing of that information to all users.
The documentation of mangrove distribution and diversity will need to include a rigorous analysis of the global, national and regional (sub‐national) significance of mangrove sites around Australia. To do this requires some form of measurement of the global, national and regional (sub‐national) significance of any mangrove area. Determining the significance of any area provides the basis for conservation actions to implement measures to maintain those values. A set of criteria for the assessment of the global, national and regional (sub‐national) significance of any mangrove area are provided in Table 6.2.
Table 6.2: Proposed definitions of the levels of "significance"
Globally significant A feature that is unique, special, rare, or few in number, globally; examples: the Bahama Banks system is a globally unique system; most poleward mangroves in the world at Wilson’s Promontory
Nationally significant A feature that is unique, special, rare, or few in number, nationally; the same feature, therefore, may be represented elsewhere globally, but not well represented elsewhere within a nation; examples: the high‐tidal mangrove‐vegetated alluvial fan habitats in the arid setting of the Pilbara, distinct arid mangrove assemblages including
Camptostemon schultzii; highest biomass mangrove assemblages in complex structural
formations around 25 m tall in northern Queensland adjacent to Wet Tropics rainforest.
Regionally significant
(assessed within each Coastal Sector)
Unique or rare occurrence within a coastal sector of regional importance perhaps represented elsewhere globally or nationally but not elsewhere in the Sector; examples: laterally extensive stands of mangroves that support the near‐shore ecosystems; exceptionally well developed mangrove vegetation within a ria coast embayment.
Objective B: Minimising impacts on mangrove habitats including the sustainable utilisation of
mangrove diversity
Current use of the coastal environment is increasing and pressure on mangroves from anthropogenic impacts is higher than ever before. Minimisation of impacts through careful coastal planning that integrates protection of some mangroves with controlled development in designated areas is a key element of the strategy. Under the Convention on Biological Diversity the sustainable use of biodiversity is a key component of the overall strategy for maintaining biological diversity. In Australia regular sustained use of mangroves is limited, with indigenous peoples’ use provided for under Australian law. Notwithstanding the few current sustained uses, there are growing pressures for mangrove removal and so it is worthwhile to outline a strategy for controlled use of mangrove resources in a sustainable manner and for minimisation of mangrove habitat destruction.
In all Australian jurisdictions particular coastal areas are either already developed, under development, or targeted for future development. All Australian States and the Northern Territory have some form of coastal policy or plan (see Chapter 8 for more details) which would allow for conservation measures to ensure appropriate development to minimise impacts on mangrove areas. Within all jurisdictions, environmental impact analysis and mitigation is required for development approval where any major adverse environmental impact is predicted. Where obvious direct threats are known (e.g. port expansion), alternative mangrove areas that are comparable to those destroyed should be managed for conservation to ‘offset’ the direct impact. Offset areas should provide compensatory habitat set aside for conservation to cover all impacted mangrove habitats and be large enough to maintain their conservation values.
Many developments have known life spans and some impacts are relatively short‐lived (such as the establishment of pipe infrastructure) and rehabilitation plans are required by law. In these
cases detailed prior mapping of the mangrove habitats and the processes maintaining them will allow successful rehabilitation to be established. Furthermore, understanding the global, national or sub‐national significance of any area (as described under Objective A above) will provide useful input to the establishment of regional conservation measures, where development is taking place, that take into account the significance of any individual stand of mangroves. At the local level within any developed (or to be developed) area with identified significant mangrove sites, the development should include strategies for minimising impacts on those mangroves.
Objective C: Conserving mangrove diversity
The overall conservation of the full diversity of mangrove habitats in Australia is a key objective of a mangrove conservation strategy. While conservation can be achieved through various means, a key tool will be through protection in protected areas. Currently, protected areas are selected to cover a broad suite of ecosystems, and at times to ameliorate threatening processes. In general, protected areas have in the past often been put in place to conserve portions of landscape of scenic or other human‐valued quality and were rarely designed to cover any individual ecosystem. In recent years, reserves have been put in place to protect endangered species and/or ecological communities. A protected area system should capture, as far as practical, representative examples of major ecosystems with broad buffer zones that, where possible, also capture underlying physical processes that maintain the ecosystems in question (Thackway & Cresswell 1992).
In general protected areas which include mangrove sites of global and national significance will be included within broader protected areas that cover larger areas of the coastal landscape. For example, the most poleward mangroves in the world at Wilson’s Promontory, Victoria are protected within a larger reserve, and are actively managed as part of the Park’s management