Freshwater Protected Area Resourcbook

3.3 Implications for the development of representative freshwater reserves

There are obvious similarities between the objectives and processes of the NRSP and the NRSMPA, and the possible development of a national system of freshwater reserves.
For example, given the fundamental similarities between management aims and processes relating to both marine and freshwater environments, the goal statements could, for the most part, be transferred directly from marine to freshwater.
The general principles of reserve selection apply to terrestrial, marine and freshwater environments. Margules and Pressey (2000) list six stages in systematic conservation planning:
Stages in systematic conservation planning:

Systematic conservation planning can be separated into six stages, and some examples of tasks and decisions in each are presented below. Note that the process is not unidirectional; there will be many feedbacks and reasons for altering decisions.

1. Compile data on the biodiversity of the planning region

Review existing data and decide on which data sets are sufficiently consistent to serve as surrogates for biodiversity across the planning region. If time allows, collect new data to augment or replace some existing data sets. Collect information on the localities of species considered to be rare and/or threatened in the region (these are likely to be missed or under-represented in conservation areas selected only on the basis of land classes such as vegetation types).

2. Identify conservation goals for the planning region

Set quantitative conservation targets for species, vegetation types or other features (for example, at least three occurrences of each species, 1,500 ha of each vegetation type, or specific targets tailored to the conservation needs of individual features). Despite inevitable subjectivity in their formulation, the value of such goals is their explicitness. Set quantitative targets for minimum size, connectivity or other design criteria. Identify qualitative targets or preferences (for example, as far as possible, new conservation areas should have minimal previous disturbance from grazing or logging).

3. Review existing conservation areas

Measure the extent to which quantitative targets for representation and design have been achieved by existing conservation areas. Identify the imminence of threat to under-represented features such as species or vegetation types, and the threats posed to areas that will be important in securing satisfactory design targets.

4. Select additional conservation areas

Regard established conservation areas as ‘constraints’ or focal points for the design of an expanded system.

Identify preliminary sets of new conservation areas for consideration as additions to established areas. Options for doing this include reserve selection algorithms or decision-support software to allow stakeholders to design expanded systems that achieve regional conservation goals subject to constraints such as existing reserves, acquisition budgets, or limits on feasible opportunity costs for other land uses.

5. Implement conservation actions

Decide on the most appropriate or feasible form of management to be applied to individual areas (some management approaches will be fallbacks from the preferred option). If one or more selected areas prove to be unexpectedly degraded or difficult to protect, return to stage 4 and look for alternatives. Decide on the relative timing of conservation management when resources are insufficient to implement the whole system in the short term (usually).

6. Maintain the required values of conservation areas

Set conservation goals at the level of individual conservation areas (for example, maintain seral habitats for one or more species for which the area is important). Ideally, these goals will acknowledge the particular values of the area in the context of the whole system. Implement management actions and zonings in and around each area to achieve the goals. Monitor key indicators that will reflect the success of management actions or zonings in achieving goals. Modify management as required.

These same steps could, broadly, form the basis of a national strategy aimed at establishing systems of representative freshwater reserves.

4. The need for representative freshwater protected areas

According to the Convention on Biological Diversity 1992, the conservation of biodiversity, including aquatic biodiversity, requires the protection of representative examples of all major ecosystem types, coupled with the sympathetic management of ecosystems outside those protected areas. This requirement was re-affirmed by the 2004 World Conservation Congress (see Appendix 18).

4.1 Australian freshwater ecosystems

By way of national overview, Australia, by virtue of its size, contains a large variety of different freshwater ecosystems. Broadly, the north of the continent has a monsoonal rainfall pattern, while the south generally has a temperate, winter-rainfall pattern. Rainfall in the arid and semi-arid centre is extremely variable. In the far south, Tasmania (the smallest State) captures a large proportion of Australia’s total annual surface runoff, and most of that falls in the southwest of the State. The eastern seaboard and the extreme south west of the continent are reasonably well-watered, and it is in these areas that the bulk of Australia’s population resides.
Rivers in the south-west, and the winter-rainfall areas of the eastern seaboard, tend to be groundwater fed most of the time. Rivers in the arid interior tend to be fed by occasional large rainfall events, and ephemeral rivers in the monsoonal north are principally rain fed. Permanent rivers in the monsoonal north are completely dependent on groundwater feed during the dry season. Only a tiny group of significant rivers in the entire continent feed on snowmelt, due to Australia’s relatively warm climate and low topography.
The dependence on groundwater of many of Australia's most reliable rivers has major implications for catchment management, and the allocation of groundwater resources by State agencies. The importance of dry season surface water in the monsoonal north to the maintenance of biodiversity (wet 'refuges' in a dry land) suggests that a highly precautionary approach should be taken in allocating groundwater in these areas. This is not currently the case in the Northern Territory, at least (Nevill 2001).
Aquatic ecosystems, while often appearing discrete within the landscape, are heavily interlinked with each other and with terrestrial ecosystems. They form pockets of great productivity and biological diversity, and the aquatic ecosystems themselves are often both geomorphologically and biologically complex and dynamic. Some organisms (stygofauna inhabiting deep aquifers, or sedentary fauna in perennial springs, for example) have evolved over long periods of time in very stable environments. Such animals can be endemic to quite small localities, and may be easily affected by changes in water level or quality. Others have evolved to occupy extremely variable and ephemeral environments in the arid interior of Australia. While highly adaptive, such fauna can also fair badly under man-made change.
Constantly changing patterns of erosion and deposition (driven by highly variable surface flows) create dynamic environments where stream channels move across the landscape, billabongs are formed and filled, and patterns of both riparian and aquatic vegetation change dramatically over time.
Connectivities are crucial and reflect both the structurally and functionally dynamic nature of aquatic environments. Floodplain wetlands depend on river flows. Aquifers feed, and are fed by rivers, streams, lakes and wetlands. Riparian vegetation depends on the groundwater surrounds of rivers and streams. The ecologies of estuaries depend on the flows of freshwater streams and aquifers, and many native fish have life-cycles involving both marine and fresh waters.
The water of shallow and deep aquifers, of streams and rivers, of estuaries, wetlands and lakes, is all ultimately connected at some level. These linkages all have spatial and temporal dimensions that manifest themselves through patterns and rates of change across the landscape - from the shrinking of an ephemeral desert pool to the infilling of a huge lake.
The scale at which connectivities operate, (and the interdependence of ecosystem functions) must be borne in mind at all management levels, from approving permits for bores to determining the size of protected areas. Nested hierarchical approaches (sensu Frissell et al, 1986; Naiman et al., 1992) are important. There is potential to relate these concepts across to the size of reserve issue, and notions of representativeness, uniqueness and functionality of reserves.
The complex and highly variable nature of Australian aquatic ecosystems has obvious implications for the design and selection of aquatic reserves. In many cases it is possible to provide protective fencing for an area of terrestrial habitat, however fencing off an aquatic reserve will offer very little protection if the immediate catchment is degrading, if upstream waters are dammed or extracted, or weirs downstream stop the normal migration of fish. Ideally, aquatic reserves will need to be part of protected landscapes, and, given the dynamic nature of aquatic habitats, reserves will also need to be large enough to integrate natural patterns of change.
By world standards, Australia has only one large river system, the Murray-Darling, whose catchment drains the western slopes of the Great Dividing Range. The Murray-Darling Basin covers an area in excess of a million square kilometres (over one seventh, or 14% of the entire continent) and occupies large areas of southern Queensland, inland NSW, and northern Victoria, as well as South Australia's south east. The Murray-Darling is also one of Australian’s most degraded river basins, an issue of special concern to South Australia – the State at the “bottom end” of the basin catchment. Many exotics (for example carp and willows) inhabit the basin, which is highly modified and flows highly regulated. Expert-panel estimates of the declines in the system's native fish populations indicate that, on average, their overall abundance has fallen to about 10% of pre-1800 levels. Eight species are listed nationally as vulnerable or endangered, with many local extinctions (MDBC 2003).
New Zealand is a land of mountains, lakes and rivers. Like Australia, introduced game fish (eg: trout) have taken a significant toll of native freshwater fish. Unlike Australia, many of New Zealand's most reliable rivers feed on rain and snow-melt.