4.3 The roles of freshwater protected areas
Essentially, protected areas are created to protect identified values, existing in a specific location, from identified threats – which may be both direct and indirect. Values can be both qualitative and quantitative, and can be measured by attributes, and assigned levels (see Appendix 7).
As is the case in terrestrial and marine environments, there are a number of roles that protected areas can play in relation to inland aquatic ecosystems. These include:
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at a national level, protection of biodiversity against threatening processes through the establishment of a comprehensive, adequate and representative system of protected areas containing examples of all major inland aquatic ecosystems in relatively undisturbed condition;
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the facilitation - through a process of the identification of natural values, ecosystem condition, and threats - of broad strategic planning processes aimed at the protection biodiversity within the entire landscape;
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provision for the conservation of special groups of organisms – for example, species with complex habitat requirements, or mobile or migratory species, or species vulnerable to disturbance and which may depend on reservation for their conservation, or species heavily dependent on particular (possibly threatened) habitats during certain life history stages;
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provision for the special needs of rare, threatened or depleted species, and threatened or unique ecological communities;
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provision of biodiversity ‘banks’ to recolonise damaged or degraded environments, whether such degradation has occurred by natural disaster, bad long-term management practices, or by accident (such as a major pollutant spill);
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provision of scientific reference sites, either for research, or to provide benchmark indicators by which sustainable management may be judged;
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protection of areas of high conservation value including those containing unusual diversity of habitats, communities or species; rare or threatened geological or geomorphological features; natural refugia for flora and fauna; and centres of species endemism;
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protection of areas sufficiently large to allow extremely long term processes to take place, such as the evolution of species or landscapes;
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assistance in the provision of ecosystem services: that is the provision of environments which sustain human life, including clean air and water, fertile soils, food, transport, flood mitigation, and the regulation of global weather patterns; and;
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within the constraints of the above, provision for the recreational, aesthetic and cultural need of indigenous and non-indigenous people.
Outstanding examples of sites which need urgent reservation to protect site-specific values are the artesian springs associated with the Great Artesian Basin (mound springs). These unique habitats contain a diverse endemic fauna (fishes, invertebrates). While some springs are now protected in South Australia, virtually none of those in Queensland are protected, including the group with the largest endemic fauna (Edgbaston Springs). Increasing evidence of extraordinary endemism in some groups (especially molluscs and crustaceans) shows that many taxa are confined to single streams or watersheds83. Reservation alone, of course, would be useless if developments in the region seriously deplete groundwater stocks and flows. The establishment of freshwater reserves would facilitate strategic catchment planning focused on the protection of specific aquatic ecosystem values. The designation of reserves should be accompanied by catchment and aquifer management programs.
4.3.1 Protection of biodiversity
All major biodiversity strategies worldwide are based on the principle of protecting biodiversity "in-situ". Biodiversity is generally defined at three levels: genes, species and ecosystems84. There are species which can be maintained by captive breeding programs, and to this extent these species, and their genes, can in theory be maintained without the existence of reserves protecting their habitat. These species represent, however, only a tiny fraction of the total number of species in existence. A large proportion of invertebrate and microbial species remain unidentified and undescribed to science. Estimates of the total number of species in existence range from 10 million to 100 million.
While most vertebrate and the majority of plant species have almost certainly been identified, full knowledge of their ecological requirements is available for comparatively few, and for most of these, captive breeding programs are impractical or uneconomic. There are many species where captive breeding programs are impossible. The American Passenger Pigeon died out in spite of intensive attempts at captive breeding programs - it is thought that this bird needed (in part) the presence of a large flock to stimulate breeding behaviour. Once the large flocks were destroyed by overharvesting, the remaining birds stopped breeding. Today, numbers of Pandas are declining worldwide, in spite of intensive efforts at captive breeding, and at first glance comparatively simple dietary requirements (bamboo shoots).
At the third level of biodiversity, 'captive breeding' programs for entire ecosystems is generally impractical or uneconomic, if not impossible. Even attempts to create simplified ecosystems to support small numbers of humans (biodomes) have been unsuccessful, although conducted at great expense85.
A cornerstone of biodiversity protection (first articulated in the international context in the World Charter for Nature 1982) is the tenet that, where ecosystems are subject to significant modification by humans (through harvesting, pollution, resource extraction, or the introduction of new species, for example) it is necessary to set aside representative examples of these ecosystems to provide biodiversity “banks”, and benchmarks against which human management of the ecosystems can be measured in the long term.
The “mirror” of this tenet states that actions should also be taken in managed (utilised) ecosystems to minimise human impacts by protecting natural values (including biodiversity) as far as practicable. Threatening processes in the broad landscape need to be identified and managed within the context of the current landuse. While representative reserves are vital, they will never be completely adequate to protect all biodiversity values86.
Where reserves are created to protect representative ecosystems, such reserves should be ecologically viable. They should be large enough to support species at the top of the food chain, such as the peak predators, and should be of sufficient size to permit ongoing evolutionary processes to occur. As discussed above, aquatic systems are dynamic, changing in both form and location within the landscape; reserves must be large enough to allow for these changes. Inventories of aquatic ecosystems may need to accommodate changes in wetland type which may take place over the medium to long term.
The above cornerstone is one of the key foundations of the international Convention on Biological Diversity, and has been broadly adopted by all national biodiversity strategies developed by signatory-nations to the Convention, including Australia's strategy. The Australian biodiversity program was established by the National Strategy for the Conservation of Biological Diversity 1996, to which all Australian States are signatories. This is referred to below in shorthand form as the national biodiversity strategy. This strategy was developed to provide a framework for Australia’s programs carried out in recognition of both international responsibilities87 and ongoing national responsibilities and programs (within the framework established by the Australian Constitution). These are discussed in the appendices in more detail.
In summary, the development of systems of representative reserves, protecting viable examples of all major ecosystems, is fundamental to the conservation of biodiversity. Where samples of ecosystems cannot be viably protected in the long-term, biodiversity losses will inevitably occur, as human use of these ecosystems modifies and simplifies their characteristics.
4.3.2 Protection of other ecological values
While biodiversity is a major determinant of the need for reservation, other ecological values may also require protection. A recent publication by Phillips et al.88 reviews existing principles and tools associated with the protection of the ecological values of rivers. Ecological value can be considered the natural significance of ecosystem structures and functions, expressed in terms of their quality, rarity and diversity. While such values are a human construct, they incorporate inherent ecological components which are not directly expressed in some biodiversity measures, and may warrant further consideration.
Significance can arise from individual biological, physical or chemical features or a combination of features. Dunn89 surveyed a range of river researchers/managers to determine the key criteria which define the aspects of rivers that should be protected. A summary of criteria identified by the survey recipients is listed below.
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rarity - what is the relative occurrence of river features?
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naturalness - how much has human occupation affected the river?
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diversity - what is the range of biological and physical features which define the river?
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representativeness - how well does the river reflect its type?
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special features - are there distinctive features of a river which require specific management?
Values and importance criteria are further discussed in Appendix 7.
Effective river protection or conservation must involve both ‘conservationists’ and those who exploit natural resources, together with researchers, planners, educators and the general public90. There is very little protection of rivers using protected area concepts being undertaken in Australia. This situation is not dissimilar to that in other countries. For example, Collier91 reported that, in New Zealand, conservation efforts had historically focussed largely on preserving fisheries values. Allan and Flecker92 claim that the strong global interest in biodiversity has concentrated efforts into ecosystems such as tropical moist forest, to the detriment of other systems such as aquatic environments, with perceived lower biodiversity levels or values.
Dunn93 described the status of river protection in Australia, with mostly indirect protection being achieved through compliance with the CoAG water reform framework agreed between State and Federal governments (this incorporates the National Water Quality Management Strategy94). This agreement commits all Australian jurisdictions to the protection of the aquatic environment, explicitly including the provision of water allocations for maintenance of these values - where they are flow-dependent.
Protection of water quality is another indirect instrument for the protection of ecological values. Direct protection instruments, for example through protection of representative river ecosystems by special designation, are not generally applied. Historically, a good deal of river protection has been achieved as a secondary outcome of the need to prevent the erosion of farmland, or the need to implement sustainable land use practices etc (L. Penn (WA WRC) pers. comm. Sept 2000).
4.3.3 Provision of benchmarks
Representative reserves provide benchmarks against which environmental changes in managed ecosystems can be measured. Benchmarks are also necessary to assess the value and condition of impaired ecosystems95.
For example, the AusRivAS macroinvertebrate sampling program provides important benchmarks and indicators for the measurement of river condition. In the long term, such benchmarks may be altered by aspects such as climate change. Without reference areas, there will be no reference standard by which to judge the implications of such long term changes.
Sustainable management programs cannot be validated without benchmarks. Without the benchmarks provided by representative reserves, programs aimed at achieving sustainability are likely to become, in the long term, vacuous attempts at window-dressing.
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