7 management template - OzCoasts 7: management template 309 Information on the vegetation ecology and management of the Barwon River estuary is available in Yugovic (1985, 2006), Yugovic

chapter 7: management template 305

7 management template

Chapter 1 of the report outlined the wide range of threatening processes that affect mangroves and coastal saltmarsh in Victoria, and Chapter 2 summarised the legislative and policy frameworks within which these areas are managed. The discussion below takes those generalised overviews and applies them to a specific coastal area with extensive coastal saltmarsh: the Barwon River estuary in central-western Victoria, 95 km south-west of Melbourne.

As mangroves and coastal saltmarsh are under increasing anthropogenic pressures in Victoria, there is an urgent need to better protect and manage them. Better management involves retaining, rehabilitating and, where appropriate, revegetating estuarine wetlands by the use of statutory planning mechanisms, combined with on-ground monitoring programs firmly embedded within a framework of scientific and local knowledge of mangrove and saltmarsh ecology. As often so little is known about the ecology of estuarine wetlands in Australia, adaptive management is a useful approach for monitoring the effectiveness of management and rehabilitation efforts (e.g. see Walters 1986; Gentile et al. 2001; Allan & Stankey 2009). Some literature tailored to the rehabilitation of Australian coastal wetlands is now available (e.g. Department of Environment and Climate Change 2008a,b; Adam 2009b). In more general terms, though, the ten basic principles identified by Zedler (2006) are worth restating for wetland rehabilitation:• Consider the hydrological, geomorphological and ecological landscape, along with the prevailing climate• Adopt a dynamic landscape-scale perspective• Restore or develop naturally variable hydrologic conditions that existed before disturbance• Where possible, chose to rehabilitate rather than to create wetlands• Avoid over-engineered structures• Pay particular attention to soil types, water depths and planting schedules• Provide suitably heterogeneous topography• Pay attention to subsurface conditions, including sediment biogeochemistry and groundwater issues• Consider the complications associated with rehabilitation or wetland creation in seriously degraded sites• Undertake monitoring early in the adaptive management process.

The management template developed for this part of the report identifies a range of important issues often confronted by natural resource managers and means by which they can be addressed. Although not all issues will arise with every mangrove or saltmarsh and not all actions are relevant to every location, the basic aims of the management of mangroves and coastal saltmarsh are to:• Allow natural ecological processes to operate as far as possible• Allow space for future change, especially sea-level rise• Prevent or minimise human disturbance, including inadvertent changes in hydrology• Eradicate or control introduced plants and animals.

In one respect the management of mangroves and saltmarshes is probably simpler than of ecosystems that require periodic reductions in biomass, such as grassland, heathland and some types of woodlands and forest. These systems need reductions in biomass, usually by processes such as fire, grazing or slashing, to maintain biodiversity. It is often logistically difficult and expensive to apply such management tools even in terrestrial environments, especially when the need for follow-up weed control is included. In contrast, mangroves and coastal saltmarsh, as with a small number of other ecosystems such as temperate rainforest, usually require no biomass reduction and are best kept in a completely undisturbed condition. On the other hand, however, mangroves, coastal saltmarsh and other types of estuarine or intertidal wetland are often difficult to access.

mangroves and coastal saltmarsh of victoria: distribution, condition, threats and management306

This can pose a serious challenge to management, especially in relation to tidal inundation and passage through muddy terrain. Nonetheless, management operations are carried out in such difficult situations in Victoria, with techniques including aerial spraying of *Spartina by helicopter (e.g. Chapter 1.12) and carefully timed boat access (e.g. Chapter 3).

7.1 Whatneedstobeinamanagementtemplate?

A natural-area management plan should contain the following elements:• Good content in terms of an informed and scientific approach to protecting biodiversity, with

information on natural values (which always includes flora and fauna but may include also genetic diversity, landscape attributes, and ecological function) and clear identification of legal and policy requirements, management issues and required responses

• Realistic and achievable aims and objectives based on available resources• Suitable format and appearance with informative maps and illustrations, in order to be readily

understood and implemented.

Although many formats for a management plan are available, the general structure of an effective plan is fairly basic. Table 7.1 shows the typical contents of a natural-area management plan.

Table7.1: Typical contents of a natural-area management plan.

Topic Typical contents

Cover page Title of plan, authorship; photo optional

Title page Details of plan publication, date

Acknowledgements People who contributed to the plan

Contents Contents page

Introduction Introduces the management plan, its background and purpose

Management area Describes the area, its general environment, its legal tenure and management history; divides the area into management sections for strategy and communication purposes

Natural values Summarises the geology, geomorphology, flora, fauna, ecology and other significant values of the area

Legislation and policy Summarises the relevant laws and government policies that relate to the management area, with emphasis on any legal obligations to protect and/or manage the area

Management issues and actions Identifies and discusses management issues and options; includes management actions individually numbered to facilitate communication and review of effectiveness

References Includes all cited references; additional references are optional

Appendices

Appendix 1. Flora List of flora, includes date and sources of most recent record/observation of each species

Appendix 2. Fauna List of fauna, includes date and source of most recent record/observation of each species

Appendix 3. Management timetable

Timetable of works over the lifetime of the plan (typically 10 years), budget if appropriate

Figures

Figure 1. Location Map of location of management area

Figure 2. Management area Map of management sections or zones

Figure 3. Natural features Map of significant flora and fauna occurrences and other significant features

Figure 4. Management information Map of management information such as weed infestations, material needing removal, etc.


7.2Case-studysite–BarwonRiverestuary

The site selected for the management template is the large area of mangrove and coastal saltmarsh in the Barwon River estuary, one of the largest estuaries in Victoria (Figure 7.1). The estuary extends from the Barwon River mouth at Barwon Heads to the southern edge of Geelong. Much is located within the 3,300 ha Lake Connewarre Wildlife Reserve, which includes the Lower Barwon, Lake Connewarre (the largest lake in central Victoria and tidal), Murtnagurt Swamp, Salt Swamp, Hospital Swamp and Reedy Lake. The remaining part is on private land.

Figure7.1: Map of the Barwon River estuary.

The Lake Connewarre Wildlife Reserve, also known as the Lake Connewarre State Game Reserve, is managed by Parks Victoria. A game reserve is a type of wildlife reserve in which flora and fauna are legally protected, except for an open hunting season declared on certain duck species in the autumn of certain years. The land is reserved under the Crown Land (Reserves) Act 1978. The Wildlife Reserve forms an important part of a Wetland of International Importance and is listed under the Ramsar Convention: Port Phillip Bay (Western Shoreline) and Bellarine Peninsula. Ramsar sites in Australia are considered matters of national environmental significance under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.

The Barwon River estuary is an extensive wetland ecosystem which shows a gradual progression from saline to freshwater conditions from the sea, and is characterised by large areas of native vegetation interspersed with shallow brackish-water lakes. Much of the estuary is in relatively natural condition, particularly in the lower section between Lake Connewarre and the river mouth at Barwon Heads (the ‘Lower Barwon’). The estuary has among the most diverse saltmarsh and estuary vegetation in south-eastern Australia, with major occurrences of both wet and dry saltmarsh ( Jeff Yugovic, pers. obs.). Table 7.2 shows the area of saltmarsh and estuarine vegetation in the estuary, based on the mapping described in Chapter 5. In total, there are ~2,008 ha of saltmarsh and estuarine vegetation, of which 1,351 ha (~67%) are reserved within the wildlife reserve.


Table7.2: Saltmarsh and estuarine vegetation of the Barwon River estuary. Areas are based on the mapping described in Chapter 5.

EVC(existing or proposed)

Description Area (ha)

Reserve Private Total

EVC 140 Mangrove Shrubland

Avicennia marina shrubland 43 3 46

EVC 10Estuarine Wetland

Juncus kraussii rushland 113 11 124

EVC 947Brackish Lignum Swamp

Muehlenbeckia florulenta shrubland

88 16 104

EVC 196Seasonally Inundated Sub-saline Herbland

Wilsonia spp. herbland 80 0 80

Coastal Tussock Saltmarsh Austrostipa stipoides grassland

< 1 9 10

Gahnia filum sedgeland 355 103 458

Wet Saltmarsh Herbland Sarcocornia quinqueflora herbland

246 381 627

Suaeda australis herbland 47 40 87

Hemichroa pentandra herbland

< 1 < 1 < 1

Wet Saltmarsh Shrubland Atriplex cinerea shrubland < 1 < 1 < 1

Atriplex paludosa shrubland 2 < 1 2

Tecticornia arbuscula shrubland

76 25 101

Coastal Saline Grassland Distichlis distichophylla grassland

88 4 92

Coastal Dry Saltmarsh Frankenia pauciflora herbland

22 4 26

Disphyma crassifolium herbland

1 < 1 1

Coastal Hypersaline Saltmarsh Tecticornia halocnemoides shrubland

< 1 < 1 < 1

Tecticornia pergranulata shrubland

52 112 164

Notes:1 To obtain area figures, mosaic map polygons (data from this study) were split into equal component units, including 3-way mosaics

of species-based units. Those units differ from our recommended EVCs, so the figures presented here differ slightly from those presented elsewhere (see Appendix G).

2 Marine EVCs in the reserve/estuary: Sea-grass Meadow3 Dry coastal EVCs in the reserve/estuary: Coastal Alkaline Scrub, Berm Grassy Shrubland4 Freshwater wetland EVCs in the reserve/estuary: Lignum Swamp, Tall Marsh, Aquatic Sedgeland, Aquatic Herbland5 Other EVCs recorded in the reserve/estuary not accepted here: Plains Saltmarsh, Brackish Sedgeland, Brackish Grassland, Floodplain

Riparian Woodland, Cane Grass – Lignum Halophytic Herbland, Plains Brackish Sedge Wetland.


Information on the vegetation ecology and management of the Barwon River estuary is available in Yugovic (1985, 2006), Yugovic et al. (2003, 2004), Awal (2006), Ecological Associates (2006), Dahlhaus et al. (2007), Billows & Gwyther (2008) and Ecology Partners (2008). Most recently, Scally (2010) has completed a BEnvSci (Hons) thesis on perceptions of climate change and adaptation responses for the Barwon River estuary. Thus although some valuable knowledge has been obtained to date, the ecology of the estuary is still not particularly well understood or documented. In response to community concern about water quality and algal blooms in Lake Connewarre, the Lake Connewarre Values Project is underway to better understand the ecology and management needs of the lake.

7.3 Legislationandpolicybackground

Chapter 2 provided a detailed overview of the policy and legislation relevant to Victorian mangroves and coastal saltmarsh. A guide to the government legislation, policies and strategies specifically relevant to the Barwon River estuary is provided in the following text. In general these instruments control the types of development that can occur within the estuary, but do not oblige the landowner or manager to actively manage the natural values.

commonwealth legislation

The Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) applies to developments and associated activities that have the potential to significantly impact on Matters of National Environmental Significance, which include:• Listed threatened species• Listed ecological communities• Listed migratory species• Wetlands of international importance (Ramsar sites)• Commonwealth land.

Any person proposing to take an action that may, or will, have a significant impact on a Matter of National Environmental Significance must refer the action to the Australian Government Minister for the Environment, Heritage and the Arts for a determination of whether the action is a ‘controlled action’ or not. The Lake Connewarre Wildlife Reserve is a major part of a Wetland of International Importance listed under the Ramsar Convention and is therefore subject to the EPBC Act.

The EPBC Act is a stand-alone piece of Commonwealth legislation which has little integration with Victorian planning and environmental legislation. For major forms of development, the Act works well in terms of referrals and applications for consent. For smaller developments, however, there is a greater risk of oversight regarding development referrals under the Act because of its separation from state-based legislation. For example, a development that may not require a planning permit under the Greater Geelong Planning Scheme but that may require consent under the EPBC Act raises the risk of failing to comply with the EPBC Act because there is no obligation for the council to advise or forewarn the proponent of a development of obligations under the Act. This is a significant legislative gap.


victorian legislation

The Flora and Fauna Guarantee Act 1988 (FFG Act) provides for the conservation of threatened species and communities and for the management of potentially threatening processes. A permit from the Department of Sustainability and Environment is required to take protected flora from public land, but a permit is generally not required for removal of protected flora from private land. Authorisation under the FFG Act is required also to catch, possess, keep or sell listed fish. ‘Take’ in the Act has a wide range of meanings.

The Planning and Environment Act 1987 controls the planning and development of land in Victoria, and provides for the development of planning schemes for all municipalities. Of particular relevance to development proposals are the native vegetation provisions under Clause 52.17, which require a planning permit to remove, destroy or lop native vegetation including dead native vegetation, subject to certain exemptions.

The native vegetation controls under the planning scheme require the responsible authority to consider a variety of biodiversity and other information, including Net Gain policy, biodiversity values and conservation, the land-protection role of native vegetation, the quality, condition, location and significance of native vegetation, and the impact of vegetation removal. The planning scheme defines ‘native vegetation’ as ‘plants that are indigenous to Victoria, including trees, shrubs, herbs and grasses’ (Clause 72). The need for a permit to remove native vegetation may be also be triggered by planning overlays.

Two significant gaps between these two pieces of leigislation are the inability of the Flora and Fauna Guarantee Act 1988 to have a strong influence over private land, and the vagaries of local governments to fully utilise their powers under the Planning and Environment Act 1987.

The Wildlife Act 1975 provides for protection and management of wildlife in Victoria. The Wildlife Regulations 2002 of the Act prescribe penalties for certain activities relevant to wildlife, including disturbance of habitat without appropriate authorisation (Section 9). Authorisation to destroy or possess wildlife may be required (Sections 41–47) if wildlife needs to be moved or destroyed during development.

The Water Act 1989 provides a framework for the allocation and management of surface water and groundwater throughout Victoria. It provides a principal mechanism for maintenance of ecosystem functions including those of aquatic ecosystems. Any construction or maintenance activity that affects beds and banks of waterways, riparian vegetation, quality or quantity of water, requires a licence, permit or approval from the relevant authority. The relevant authority for the Barwon River estuary is the Corangamite Catchment Management Authority. Often, however, permits for works on waterways are focussed on declared waterways or are retrospective in terms of approving works that have already been undertaken.

The Environment Protection Act 1970 underpins the State Environmental Protection Policies (SEPP) which provides a legal framework for the protection and rehabilitation of Victoria’s surface-water environments. The uses and values of the water environment are known as ‘beneficial uses’. Environmental quality objectives and indicators are defined to protect beneficial uses and an attainment program provides guidance on protection of the beneficial uses. The beneficial use of most relevance to biodiversity is ‘aquatic ecosystems’. The Policy requires that aquatic ecosystems be protected. Impacts to surface-water quality must not result in changes that exceed water-quality objectives specified to protect beneficial uses. Proponents and land managers need to


ensure that direct and indirect (e.g. runoff ) impacts to surface-water quality do not exceed the water-quality objectives. The SEPP provides recommendations to ensure that beneficial uses are protected.

State Planning Policy Framework Clause 15.01 (Protection of catchments, waterways and groundwater) states that planning and responsible authorities must have regard for the objectives of the Corangamite Regional Catchment Strategy. The Corangamite Regional River Health Strategy provides further recommendations on the protection of existing high value rivers and creeks that are in good condition and strategic improvement of other rivers and creeks.

The Catchment and Land Protection Act 1994 (the CaLP Act) provides for a system of controls on noxious weeds and pest animals. The Act specifies four categories of noxious weeds in Victoria: i) State Prohibited weeds; ii) Regionally Prohibited weeds; iii) Regionally Controlled weeds; and iv) Restricted weeds.

State Prohibited weeds either do not occur in Victoria but pose a significant threat if they invade, or are present, pose a serious threat and can reasonably be expected to be eradicated. If present, infestations of a State Prohibited weed are relatively small. They are to be eradicated if possible from Victoria or excluded from the state. The Victorian Government is responsible for their eradication, but under Section 70(1) of the CaLP Act it may direct landowners to prevent their growth and spread.

Regionally Prohibited weeds are not widely distributed in a given region but are capable of spreading further. It is reasonable to expect that they can be eradicated from a region and they must be managed with that goal. Landowners, including public authorities responsible for Crown land management, must take all reasonable steps to eradicate Regionally Prohibited weeds on their land.

Regionally Controlled weeds are usually widespread and are considered important in a particular region. To prevent their spread, continuing control measures are required and landowners have the responsibility to take all reasonable steps to prevent the growth and spread of Regionally Controlled weeds on their land.

Restricted weeds includes plants that pose an unacceptable risk of spreading in the state or to other parts of Australia if they were to be sold or traded in Victoria, and are a serious threat to another state or territory of Australia. Trade in these weeds and their propagules, as plants, seeds or contaminants in other materials, is prohibited.

None of the serious weeds within the Barwon River estuary, such as Tall Wheat Grass *Lophopyrum ponticum or *Spartina spp., are declared noxious in Victoria, so the CaLP Act has little or no relevance to the management of saltmarsh and estuary vegetation in the study area.

Enforcement action, both in terms of ability and willingness to effectively undertake enforcement of legislation such as water quality by the EPA or weed management by the Department of Primary Industries, is often lacking. There are difficulties in ensuring regulations are enforceable and in securing evidence to pursue enforcement action.

local government

The City of Greater Geelong planning scheme is given effect by the Planning and Environment Act 1987. The planning scheme contains the Victorian Planning Provisions referred to in Chapter 2, and has local planning overlays that control development within specific areas. Specified actions, which may include the removal of


native vegetation, require a planning permit from the City of Greater Geelong. Any permit issued must have regard to the planning scheme and its overlay provisions.

The Public Conservation Resource Zone (PCRZ) is generally applied over the Barwon River estuary including Lake Connewarre. The purposes of the PCRZ are to:• Implement the State Planning Policy Framework and the Local Planning Policy Framework, including

the Municipal Strategic Statement and local planning policies• Protect and conserve the natural environment and natural processes for their historic, scientific,

landscape, habitat or cultural values• Provide facilities which assist in public education and interpretation of the natural environment with

minimal degradation of the natural environment or natural processes• Provide for appropriate resource-based uses.

The zoning of land adjoining the estuary ranges from the Farming Zone around Lake Connewarre to the Residential Zone at Barwon Heads.

Two planning overlays apply to part or all of the Barwon River estuary: Clause 42.01 and Clause 44.03.

Clause 42.01 – Environmental Significance Overlay (ESO) has as its purposes to:• Implement the State Planning Policy Framework and the Local Planning Policy Framework, including

the Municipal Strategic Statement and local planning policies• Identify areas where the development of land may be affected by environmental constraints• Ensure that development is compatible with identified environmental values.

Under the ESO, the Barwon River estuary is covered by a Schedule to the ESO: ESO2 Environmental Significance Overlay Schedule 2 (High Value Wetlands and Associated Habitat Protection).

The ESO2 was developed by council to apply to those parts of the municipality covered by the Ramsar Convention and accordingly it covers those wetlands designated as a Ramsar site including Lake Connewarre, the lower Barwon River estuary, Swan Bay, and parts of the western shoreline of Port Phillip Bay around Point Wilson and Avalon. The environmental objectives to be achieved under the ESO2 are to:• Maintain the ecological character (the sum of the biological, physical and chemical components of the

wetland ecosystem, and their interactions which maintain the wetland and its products, functions and attributes) of Ramsar wetlands

• Protect natural resources and maintain ecological processes and genetic diversity• Protect and ensure the long-term future of terrestrial and aquatic habitat for native plants and animals,

including shorebird feeding areas and roosts, and species and communities listed under the Fauna and Flora Guarantee Act 1988

• Encourage ecological restoration, regeneration and revegetation with indigenous species within the site and in adjoining areas

• Maintain the function of the wetland or habitat area as part of the broader natural system, including maintenance of natural flows and flooding regimes

• Prevent further loss of wetland habitat• Manage the site in order to maintain and/or improve its value as a conservation site for native plants and

animals


• Protect water quality and prevent water pollution in watercourses, water bodies, wetlands and groundwater

• Protect cultural (including aboriginal and non-aboriginal heritage) values• Protect visual amenity.

The overlay relates to the Lake Connewarre Wildlife Reserve only. A permit is required to construct a building or to carry out certain works including the removal, destruction or lopping of native vegetation and to subdivide land.

Clause 44.03 – Floodway Overlay (FO) has as its purposes to: • Implement the State Planning Policy Framework and the Local Planning Policy Framework, including

the Municipal Strategic Statement and local planning policies; to identify waterways, major floodpaths, drainage depressions and high hazard areas which have the greatest risk and frequency of being affected by flooding

• Ensure that any development maintains the free passage and temporary storage of floodwater, minimises flood damage and is compatible with flood hazard, local drainage conditions and the minimisation of soil erosion, sedimentation and silting

• Reflect any declarations under Division 4 of Part 10 of the Water Act, 1989 if a declaration has been made• Protect water quality and waterways as natural resources in accordance with the provisions of relevant

State Environment Protection Policies, and particularly in accordance with Clauses 33 and 35 of the State Environment Protection Policy (Waters of Victoria) (Environment Protection Authority Victoria 2003)

• Ensure that development maintains or improves river and wetland health, waterway protection and floodplain health.

The Flood Overlay requires a permit to construct a building or to carry out certain works and to subdivide land. It is applied to both Lake Connewarre itself as well as some of the adjoining land that may be affected by inundation.

As outlined in Chapter 2, the zones and overlays that have been used and how they have been applied under the Greater Geelong Planning Scheme over the Barwon River estuary reflect inherent limitations in the management framework. The PCRZ is a public land based zone that has been applied correctly over the public land areas of the Barwon River estuary. However the ESO2 is restricted to being applied only over the public land area of the Barwon River estuary because it has been applied only to the Ramsar site, which in this case covers only public land (i.e. the Ramsar site designation does not cover private land). The private land adjoining the Barwon River estuary do not have any conservation-based zone or overlay. Therefore, the relative importance of the operation of the EPBC Act increases with regard to regulating the impacts of development on private land adjoining the designated Ramsar Wetland.


A better planning configuration for the Barwon River estuary would be as follows:• Public land component – maintain the manner of application of the PCRZ and ESO2• Private land component adjoining the Barwon River estuary in rural areas – apply the Rural

Conservation Zone (RCZ) and ESO2 at least to a distance from the high-water mark of 200 m to adequately cover water quality, direct impacts and climate change induced sea-level rise impacts

• Private land component adjoining the Barwon River estuary in urban areas – apply the ESO2 at least to a distance from the high-water mark of 200 m to adequately cover water quality, impacts from further intensification of development, direct impacts and climate change induced sea-level rise impacts.

Finally, the Greater Geelong Planning Scheme influences the lower Barwon River estuary through the planning policy for the township of Barwon Heads. Clause 21.14 of the council’s Municipal Strategy Statement (MSS) is the planning policy that covers Barwon Heads and Ocean Grove which recognises that these places are located within a sensitive natural environment. The Barwon River, Lake Connewarre system and coastline of Bass Strait form major boundaries to the townships, influencing growth options for the future. The planning policy for Barwon Heads seeks to maintain a village atmosphere and limit urban growth despite strong pressures for urban expansion and to avoid impacts on environmental assets such as the Barwon River and Lake Connewarre from development in both townships.

Council undertook a review of the future of Barwon Heads through the preparation of a structure plan for the town which was adopted in December 2007 and which has implications for the adjoining coastal saltmarsh and mangroves within the estuary. The structure plan recognised the importance of the setting of the town adjacent to the river estuary, and coast. It includes policies to ensure the protection of the coastal saltmarsh and mangroves as part of the environmental values of the town’s setting. It identifies also the need to investigate applying an overlay relating to the environmental significance of the coast over parts of the town and extending across the estuary. Figure 7.2 demonstrates the structure plan’s directions for the environmental features of Barwon Heads. Although the structure plan has been adopted by council, it does not yet form part of the Greater Geelong Planning Scheme and an amendment to the planning scheme has been prepared and is awaiting approval.


Figure7.2: Extract from the Barwon Heads structure plan, showing how the plan identifies and outlines policy directions for the town with respect to the Barwon River estuary and Murtnagurt Lagoon. Source: City of Greater Geelong (2007).

7.4 Managementissues

Chapters 1.11–1.13 provided a statewide overview of the main threats to mangroves and coastal saltmarsh. That summary is expanded in the following section and is illustrated with specific examples drawn from the Barwon River estuary and the actions that need to be taken to ameliorate the threats. The issues may be classified into three main categories – planning, catchment and site-management issues:• Planning issues ○ land-use zoning ○ knowledge base ○ planning for sea-level rise ○ infrastructure syndrome ○ annual program• Catchment issues ○ freshwater runoff ○ pollution ○ eutrophication ○ sedimentation ○ environmental flows ○ buffer protection ○ landscape protection


• Site-management issues ○ landfill ○ foreign geological material ○ physical disturbance ○ tidal restriction ○ estuary entrance opening ○ pest plants ○ pasture improvement ○ pest animals ○ stock grazing ○ shell-grit mining ○ rubbish dumping ○ incursion ○ unauthorised use ○ boat wash ○ boardwalks ○ signage ○ mangrove spread ○ fencing ○ fire ○ visitor management ○ regeneration and revegetation ○ wetland construction ○ enforcement

These issues are discussed in turn below.

land-use zoning

Sensitive and appropriate land-use zoning is essential for the protection of mangroves, saltmarshes and estuaries. Planning schemes need to reflect the significance of these systems by placing them and, importantly, their buffers within appropriate land-use zones with protective overlays. The fauna, flora and environments of saltmarshes and estuaries near human land use can be adversely affected by many factors, including loss of landscape quality, inputs of fresh water, noise, light, cats, dogs and visitor pressure. The approach taken towards land use on the edges of mangroves, saltmarshes and estuaries can range from high-density housing (inappropriate) to dedicated open space (appropriate). Protecting the edges of these natural areas is fundamental to many of the management issues below.

ExamplefromtheBarwonRiverestuary

The public land (Wildlife Reserve) is zoned Public Conservation and Resource Zone (PCRZ) and has an Environmental Significance Overlay (ESO), but it has no buffer zone and thus one of Victoria’s largest estuaries is subject to adjacent land uses and developments that adversely affect its landscape value and ecology.


Necessaryaction

• Prepare and apply appropriate protective land-use zones and overlays to saltmarshes and estuaries and their adjoining areas. Dedicated open space is appropriate around estuaries near human habitation.

knowledge base

Good working knowledge of the estuary or saltmarsh and its ecology is necessary for the conservation management of such a dynamic natural area. The geomorphology of the marsh is important to understand as it explains much of the vegetation pattern, informs knowledge of the ecological processes, and indicates the potential direction of erosion and deposition processes. An inventory of the flora and fauna is essential, and species of significance need to be identified and mapped. The ecological services that the community expects the wetland to deliver also need to be made explicit.

A vegetation-and-feature map based on recent aerial photography is needed to understand the distribution of significant ecological features and for management communication purposes. The scale used for the statewide mapping in the present study – 1:10,000 – necessarily simplifies the vegetation pattern and includes mosaics that should be resolved to component units for better understanding of the vegetation and more effective management. A scale of between 1:2,500 (1 mm = 2.5 m on the ground) and 1:5,000 (1 mm = 5 m on the ground) is usually needed to adequately capture the vegetation pattern (see Chapter 1.15 on mapping protocols). As this scale is usually sufficient to show the distribution of individual saltmarsh units (e.g. based on floristic and/or structural differences), it shows those that are rare in the local area, region or state and thus in need of special management.


Detailed mapping of vegetation in the Barwon River estuary is not currently available. A vegetation map at 1:18,500 was compiled by Yugovic (1985) which, although apparently complex, is a simplification of the vegetation pattern. It is also rapidly dating, due to vegetation change including the spread of mangroves up the river and into the lake. The 1:10,000 mapping in the present study also necessarily simplifies the pattern that occurs on the ground (see Chapter 5.3).

Necessaryaction

• Prepare an inventory of the flora and fauna, identifying species of national, state or regional significance, and, where possible, including quadrat data.

• Map the vegetation at a scale of between 1:2,500 and 1:5,000 using recent aerial photography. Map all saltmarsh units in order to avoid mosaic map units. Ground truth the mapping.

• Map the location of management features such as flora of regional or higher significance, special fauna habitats and special management zones.

• Divide the management area into logical management sections or zones, thus facilitating communication and direction of management effort. Name or number the management sections.


planning for sea-level rise

Fundamental to mangrove and saltmarsh conservation is the allowance that must be made for low-lying vegetation to migrate to higher inland sites with rises in sea level, and where appropriate to recover in areas that are presently cut off by sea walls (Chapter 1.13). Inland migration zones or buffer zones should be, and in some cases already have been, clearly identified in state and regional strategies and local planning schemes (Chapter 2). Within these zones, any further construction activity that would affect topography and hydrology is not appropriate. Such land-use zones should be formalised for example as public acquisition overlays and marine inundation overlays in planning schemes.


The Wildlife Reserve, although currently large, has effectively no room for migration. There is no public land or overlay zone on private land upstream to accommodate any migration and, in fact, the estuarine perimeter is often occupied by housing (Figure 7.3). Some areas of saltmarsh on private land near the inland limit of the estuary are proposed by developers for transfer to public land in association with urban residential development. The transfer is not for future migration of the estuary but for recreation and drainage and, indeed, landfill and development may block the possibility of any future migration. Moreover, any saltmarsh that is retained may be damaged or lost if it becomes a receiving area for urban runoff (see Chapter 1.11).

Planning for sea-level rise is currently provided for under the Victorian Coastal Strategy 2008, which establishes as state planning policy under Clause 15.08 of the State Planning Policy Framework. Every planning scheme, including the Greater Geelong Planning Scheme, has a requirement for planning authorities to plan for sea-level rise of not less than 0.8 m by 2100 and allow for the combined effects of tides, storm surges, coastal processes and local conditions such as topography and geology when assessing risks and impacts associated with climate change. The policy has no specific permit trigger, but is required to be considered for any land use or development on the coast for which a permit is required.

At present, the Greater Geelong Planning Scheme does not address planning for sea-level rise at a local level in any comprehensive way. However, the Municipal Strategic Statement (MSS) of the planning scheme has been reviewed and a revised version is currently awaiting Ministerial approval. The revised MSS does include additional planning policy statements that recognise and require consideration of the effects of sea-level rise and the need to buffer the impacts on mangroves and coastal saltmarsh. The City of Greater Geelong is working on possible amendments to its suite of overlays to better improve the planning response to sea-level rise. The work includes a review of the Environmental Significance Overlays to improve habitat protection for the Orange-bellied Parrot, which feeds on coastal saltmarsh.

Necessaryaction

• Undertake land-use planning and rezoning to allow for saltmarsh and estuary migration in response to sea-level rise.

• Formalise inundation zones within state strategies and local planning schemes.• Prevent any further construction activity that would affect topography, hydrology or the potential for

estuary movement within inundation zones.• Undertake environmental works within inundation zones, such as removing structures, removing fill and

levelling surfaces as appropriate.


Figure7.3: Housing adjacent to mangroves, Barwon River estuary.

infrastructure syndrome

All too often with reserve management, the majority of resources is allocated to infrastructure such as boardwalks, boat ramps and signage rather than to protecting and managing the natural assets the reserve was created for. This we term the infrastructure syndrome. Its prevalence is primarily due to lack of knowledge, compounded by ranking decisions, resourcing limitations and skewed conceptions of the management of natural areas. Resource management is often feeble or ignored altogether in management plans, especially when the ecological knowledge base is minimal. Effective vegetation management requires appropriate knowledge, attitudes, skills and resources, and any of these may be lacking for a given location. In some reserves, management personnel are unaware of special features, such as the rare dry saltmarsh vegetation type, that may be present in their area of jurisdiction. Such a lack of understanding can lead to inadvertent loss or damage to such features by neglect or poorly sited infrastructure.


Infrastructure in the wildlife reserve includes boardwalks, boat ramps and signage. There has been an emphasis of infrastructure management but *Spartina survey and spraying and fox control have been undertaken recently. Further management activity is planned for the future.

Necessaryaction

• Give resource management priority over infrastructure management.


annual works program

An annual works program should be prepared in accordance with the management plan prepared for the saltmarsh. The program should include achievable objectives and estimated person days and costs. It should be prepared by the end of June each year, as the vegetation management year coincides with the financial year ( July to June inclusive). Also to be prepared by the end of June is a review or audit of activities undertaken in relation to the annual program objectives. The need for planning may seem obvious, but lack of forward planning can result in management inaction and neglect even when resources are available.


Current management of the wildlife reserve includes visitor and duck-shooter management, infrastructure management (the boardwalk, boat ramps, etc.), *Spartina mapping and spraying, and fox control to protect Orange-bellied Parrot. However the overall operational budget for the reserve is low (part of $60,000 in 2009–2010 for the entire Bellarine Peninsula, which has several reserves, Lake Connewarre being the largest) and Parks Victoria does not have a boat to patrol the river and lake with. Two dedicated Rangers cover the entire Bellarine Peninsula (recently cut from six Rangers), so management of the Barwon River estuary is poorly resourced from even the perspective of personnel. Due to resource and time constraints, there are nature reserves on the Bellarine Peninsula that the Rangers have not visited. Sensitive management of saltmarsh on private land is negligible or non-existent.

Necessaryaction

• Undertake an annual review of management.• Prepare an annual works program in advance of the next year in accordance with the management plan,

and make arrangements to implement the program.

freshwater runoff

Excessive freshwater input via drains and runoff is frequently a management issue, and excessive freshwater inputs can cause major detrimental effects on mangroves and coastal saltmarsh (Chapter 1.11). Too great a dilution of salinity favours saltmarsh communities at the fresh end of the salinity range, such as Distichlis grassland, and may result in the replacement of Coastal Saltmarsh by other ecological vegetation classes such as Estuarine Reedbed, Tall Marsh or even exotic vegetation. Dry saltmarsh communities, especially Tecticornia pergranulata and Tecticornia halocnemoides shrubland, are likely to be especially badly affected, as they are restricted to sites with dry hypersaline conditions in summer, the opposite of the conditions provided by high-volume freshwater inputs.

Unnatural freshwater input may arrive from below the topographic level of the saltmarsh via a creek or river coming from the larger catchment of a saltmarsh. As long as lower saltmarsh receives regular tidal inundation and can drain readily, any fresh water is soon diluted by sea water. Alternatively, and more commonly, fresh water may arrive from above the level of the marsh via a drain from the adjacent subcatchment (Figure 7.4). This type of input is more problematic, as upper saltmarsh requires a lower inundation frequency and higher salinity than lower saltmarsh (see Chapter 1.5).


Figure7.4: Urban stormwater drain with one-way valve to prevent sand blockage, Barwon Heads.


Runoff from housing and other developments adjacent to the estuary has affected vegetation, by killing saltmarsh plants and promoting Typha spp. (in a Tall Marsh EVC) and other types of opportunistic or introduced vegetation. The drains that were constructed to channel the runoff into the saltmarsh have modified topography and damaged vegetation.

Murtnagurt Swamp supports highly significant dry saltmarsh vegetation, which is particularly susceptible to freshwater runoff. A residential development in Barwon Heads adjacent to Murtnagurt Swamp had few or no environmental requirements regarding its stormwater outfall: the drainage plan does not show where the drain terminates, and it simply runs off the edge of the development plan map into the wetland ( J. Yugovic, pers. obs.) The discharge is having ongoing detrimental effects on dry saltmarsh: since construction of the drain, the eastern area of Murtnagurt Swamp has received considerably larger volumes of water, resulting in this part of the swamp, which is a basin, remaining flooded for much longer periods. The dieback of the significant dry saltmarsh shrubs indicates adverse effects on these species in particular.

A later residential development in Barwon Heads directs runoff into a specially constructed irrigation dam on the Barwon Heads Golf Course rather than into Murtnagurt Swamp, which is preferable for the wetland. The dam is designed to fill only rarely, in which case it will overflow into the swamp (Yugovic et al. 2004). It has been operational for 2–3 years and has not overflowed. It represents an unusual and innovative use of stormwater. Another residential development adjacent to the swamp is proposed and it may not have such a mitigation measure.

Necessaryaction

• Prevent all freshwater runoff onto saltmarshes other than natural inputs.• Investigate and implement ameliorative measures where freshwater inputs are damaging saltmarsh

vegetation.


pollution

Chemical pollution, particularly from oil or fuel spills, is a threat to many areas of mangrove and coastal saltmarsh (Chapter 1.11). Moreover, industrial contamination of soft sediments near industrial sites is a major concern and is not possible to remediate, and outfalls from nearby sewage treatments plants can foul waterways. In the Breamlea Nature Conservation Reserve, seepage and runoff from solid waste mounds enters ponds within the reserve. In both cases the water is strongly coloured and has an offensive odour. Even the discharge of treated water to saltmarsh should be prevented, as fresh water and nutrients adversely affect many aspects of saltmarsh ecology.


There have been no documented chemical pollution incidents in recent years. Nevertheless, sediments in Lake Connewarre are known to have high concentrations of arsenic, cadmium and mercury due to past industrial activities and as a legacy from gold mining in the 19th century (Billows & Gwyther 2008).

Necessaryaction

• Prevent chemical pollution of mangroves and coastal saltmarsh.• Prepare a contingency plan for chemical pollution by liaising with relevant agencies such as the

Environment Protection Agency.• Prepare to contain oil spills with booms if they occur near coastal areas, and to contain spills from the

landward catchment.• Ensure that surface-water and groundwater outputs from sewage treatment plants is treated to a

satisfactory licensed standard and does not seep or flow into mangroves or coastal saltmarsh.

eutrophication

Eutrophication is an increase in the concentration of plant nutrients in an ecosystem to an extent that it increases the rate of primary productivity and the biomass of undesirable plants (see review in Chapter 1.11). Depending on the degree of eutrophication, subsequent negative environmental effects can include hypoxia or anoxia and severe reductions in water quality; death of fish and other aquatic organisms can then occur. In many aquatic systems, excess growth of algae (planktonic, benthic and attached forms) as well as of vascular aquatic plants is caused by excess nutrients entering from upstream (Figure 7.5). Shifts across vegetation types are also possible, in which case a switch in states has occurred. Controlling nutrient enrichment is a complex task relating to management of the entire river catchment. It requires multi-agency coordination and resourcing and the cooperation of landholders within the catchment.


Water quality in Lake Connewarre is a community concern (e.g. Geelong Advertiser 3/05/2008, 4/07/2009). Blooms of blue-green algae (cyanobacteria) often occur in the lake from January to March due to excess nutrients and low flows from the Barwon River, combined with high water temperature (and thus thermal stratification of the water column) in the ever-shallowing lake. When algae are detected, Parks Victoria closes the lake to recreational activity and undertakes a monitoring program. The lake is reopened when


algal abundances fall below a pre-determined trigger level. Recorded filamentous cyanobacteria include Oscillatoria and Planktothrix, which are not toxic but do cause skin irritation (S. Willsher, Parks Victoria, pers. comm.). Algal biomass and decaying aquatic plants accumulate on the north shore of the lake due to prevailing wind direction. The drying vegetation mats cause localised smothering and death of vegetation, and the accumulation of rotting plants can develop an offensive odour. In fact, the smell emitting from Lake Connewarre is known locally as the ‘Leopold pong’ (e.g. Geelong Independent 9/07/2009). There is a proposal by some landowners to dredge the tidal delta area to increase seawater flushing. Such an action would need thorough and independent scientific and engineering evaluation, especially with regard to the significant ecological features of the lake.

Necessaryaction

• Prevent or minimise nutrient enrichment of water entering the estuary from the catchment.• Ensure that any water-engineering works to minimise eutrophication have net ecological benefit to an

estuary.

Figure7.5: Masses of rotting vegetation along the shoreline, Lake Connewarre.

sedimentation

Estuaries are naturally places of gradual infilling by sedimentation, but the rate of deposition is much higher in catchments subject to extensive clearing of native vegetation than in those with large areas of native vegetation. The resulting poor vegetation cover at countless potential point sources of erosion makes streams turbid with suspended sediment, and this sediment is later deposited in the estuary when discharge falls and particles are precipitated due to increasing salinity. Controlling siltation is a complex task requiring management of the entire catchment, which requires multi-agency coordination and the cooperation of landholders (Figure 7.6).


Figure7.6: Lake Connewarre is becoming increasingly shallow due to sediment accumulation. Note also the presence of an algal scum floating on the surface.


Since the clearing of most of the Barwon River catchment, Lake Connewarre has filled with sediment (silty clay) from the eroding catchment. Originally several metres deep, it was reduced to a depth of ~1 m by the 1970s (Rosengren 1973), and is even shallower now. The lake is now longer navigable by outboard motor boat. The massive amount of infilling has caused major change in the size and shape of the lake. By comparing Richard Daintree’s 1869 map of the lake with today, it is apparent that the western side the lake has contracted due to i) extension of the Barwon River delta into the lake and ii) creation of Hospital Swamp which has been effectively been cut off from the main body of the lake by vegetated rises. Both result from siltation.

Necessaryaction

• Prevent or minimise unnatural sedimentation. It will involve multi-agency programs aimed at reducing the turbidity of water entering an estuary.

environmental flows

River regulation and extraction upstream necessarily results in the removal of large volumes of water that would otherwise pass into estuaries (Tilleard et al. 2009). Freshwater flooding, either pure or in mixture with tidal seawater to form brackish water, is vital for the viability of certain vegetation types such as Estuarine Wetland (Juncus kraussii rushland) and Distichlis-dominated grasslands. Environmental flows are managed flows, not directly used for agriculture or drinking water, that are intended to keep river and estuary systems healthy.


Diversions from the Barwon River traditionally remove large volumes of water that would otherwise pass into the lakes and swamps of the estuary. The current low flows are exacerbated by the period of drought since 1996, and there has not been a major flood of the Barwon River for over 10 years. River flooding is vital for Muehlenbeckia shrubland, Distichlis grassland, Juncus rushland and Wilsonia herbland, and these vegetation types are visibly under stress, presumably because of salinity-related factors. Algal blooms in Lake Connewarre


are related to lack of flushing by freshwater flows. The Barwon River has a recommended environmental flow determined by the statewide FLOWS method (Corangamite Catchment Management Authority 2005) but, due to low inflow, it does not receive a environmental flow at present. There is a proposal to in future divert more water from the Barwon River into Reedy Lake in order to cleanse the lake system, but the amount of extra water would be relatively small. In any case, Reedy Lake currently receives no water due to low river flow (S. Willsher, Parks Victoria, pers. comm.). Billows & Gwyther (2008, page 21) concluded that ‘efforts to provide sufficient environmental flow allocations to the estuary are important to avoid unnaturally high sedimentation rates within Lake Connewarre’.

Necessaryaction

• Ensure that environmental flows to the estuary occur where necessary.

buffer protection

Natural coastal areas benefit greatly from buffer zones in which direct impacts of human activity and indirect impacts (such as weed invasion) can be absorbed to prevent impact on the natural area itself. The effectiveness of a buffer zone depends on several factors, including size, vegetation cover, and the type of disturbance being absorbed. Generally, buffers with native vegetation function best as they intercept nutrients and weeds coming in from surrounding agricultural catchments, and are consistent with protection of natural landscapes.


The Barwon River estuary has extremely poor or non-existent buffer zones (Figure 7.7), as the reserve was created out of what was left after all of the potentially arable land had been selected in the mid 19th century. Recent urbanisation of the immediate catchment of the estuary further increases the need for buffer zones.

Figure7.7: Lack of a buffer zone around the western edge of Lake Connewarre.

Necessaryaction

• Create and manage for their protection buffer zones around saltmarshes and estuaries.• Create environmental significance overlays in planning schemes to protect saltmarsh and estuary buffer

zones.


landscape protection

Visually imposing buildings on the edges of mangroves, saltmarshes and estuaries detract greatly from the natural landscape. They are visually intrusive and are point sources of freshwater runoff which may be detrimental to the saltmarsh below.


A number of over-dominant buildings are situated on the edge of the Barwon River estuary (Figure 7.8). They have appeared in the last 25 years with little or no consideration of visual impact on the landscape.

Figure7.8: Visually dominating buildings, western shore of Lake Connewarre.

Necessaryaction

• Protect the natural landscape amenity value of coastal areas from visual intrusion by poorly sited buildings.

• Prevent the construction of buildings and earthworks on escarpments above saltmarshes and estuaries.• Create landscape protection overlays in planning schemes to protect saltmarsh and estuary landscapes.

landfill

Landfill is a major issue in many coastal areas, as it reduces the area of mangrove and saltmarsh and may affect drainage patterns. It is unsightly and saltmarsh, in particular, is often destroyed without a planning permit (Figure 7.9). As outlined earlier, coastal saltmarsh is native vegetation requiring a planning permit from local government for its destruction.


Many examples of landfill, major and minor, occur within the Barwon River estuary, on public and private land. The Barwon Heads tip, for example, was sited on saltmarsh on the Murtnagurt Swamp channel (Taits Road) but most of the material was later removed. However, rather than restoring the original surface level to facilitate the re-establishment of saltmarsh, clean fill was placed on the site (raising the surface level above that of saltmarsh) and it was planted out with locally indigenous (not site indigenous) species.


Figure7.9: Building waste used as landfill for a causeway on saltmarsh, eastern shore of Lake Connewarre.

Figure7.10: Crushed rock from drain on right spreading into estuary; the natural surrounding substrata is mud.

Necessaryaction

• Prevent saltmarsh and mangrove areas being used for landfill placement.• Remove landfill from those areas that have been affected in the past and dispose of material safely.

foreign geological material

Foreign geological material is often introduced to saltmarshes, mangroves and estuaries to make or stabilise infrastructure. Foreign material sometimes cannot be contained and will eventually be spread further from its original location (Figure 7.10). It is not always appreciated that the protection of natural geology and soil profiles is an important aim of conservation management within nature reserves.



Much foreign material has been placed on the edges of the estuary as landfill or as stabilising measures, and is spreading in places such as at The Sheepwash.

Necessaryaction

• Prevent or minimise the introduction of foreign geological material into saltmarshes and estuaries.

physical disturbance

Physical disturbance to soils and vegetation is a major problem as it is directly responsible for the loss of plants, as well as disrupting the natural surface profile, which can lead to permanent change in drainage patterns and thus vegetation. It may also facilitate weed invasion in upper saltmarsh. A wide range of physical disturbances may occur in coastal wetlands, ranging from ruts created by passage of vehicles, through damage caused by machinery digging out spiny rush, soil pugging by domestic stock, to drains cut directly into the marsh surface.

Vehicle rutting is a particular problem. Ruts are caused by removal of soil material on the wheels of vehicles and compaction of what remains. Ruts are long lasting and difficult to repair and are best prevented in the first place. To our knowledge repair has not been attempted, but should be possible. It would require i) levelling the surface using manual or, if feasible without causing further damage, mechanical methods, and ii) filling the ruts with substrate material of the same geological material and obtained without detriment to the source site. Under no circumstances should foreign geological material, such as crushed rock, be introduced as it will eventually be dispersed widely.


Disturbance by vehicles is severe in parts of Reedy Lake. Constructed drains are common, particularly on private land, but are also constructed with or without permission in the reserve (Figure 7.11). Pedestrian traffic along the banks of the river at The Sheepwash causes observable damage.

Figure7.11: Constructed drain cut into Reedy Lake.


Necessaryaction

• Prevent physical disturbance to soils and vegetation.• Install gates or barriers to prevent vehicle access to sensitive areas.• Ensure that authorised vehicles do not cause rutting, for example, by avoiding vehicle access and

movement when soils are wet.• Do not introduce foreign geological material such as crushed rock or gravel.

tidal restriction

Alteration to the natural frequency of seawater inundation often poses a major management issue, as it affects the extent of mangroves and saltmarsh, often resulting in reduction in area and, in the case of saltmarshes, can change the distribution of individual species and plant communities. Sea walls, levees, floodgates and culverts almost always have serious adverse effects on these coastal wetlands. At The Spit Flora and Fauna Reserve, for example, tidal restriction by a culverted causeway (Point Wilson Road) has lowered salinity and contributed to increased weed cover (Carr et al. 2002). In rare cases, sea walls have cut off an open marine embayment or mudflat which has become colonised by saltmarsh.


Reedy Lake is highly modified by levees, channels and inlet and outlet structures, which were originally constructed to create a freshwater wetland for duck shooting (Ecological Associates 2006). Hospital Swamp is similarly modified by water-engineering works, resulting in dramatic change in vegetation including major loss of saltmarsh. Curiously, these water-engineering works are described, promoted and sign boarded as wetland restoration projects. Murtnagurt Swamp was cut off from the estuary by a barrier around 1952 and has not received a tide from the river since (Figure 7.12). Fortunately, an attempt to hold freshwater in the significant Salt Swamp by constructing a levee across it, which would have destroyed its unique Wilsonia herbland, was unsuccessful. The failed levee remains as a scar in the vegetation and landscape of the swamp today.

Figure7.12: Levee which alienates Murtnagurt Swamp from the Barwon estuary.


Around 1970 there was a proposal to construct a barrier across the entire Lower Barwon for pasture and to provide a water storage for irrigation and recreation. That action would have destroyed most of the estuary and, had it proceeded, it would have been expensive to construct and maintain, and the enlarged Lake Connewarre, which is already shallow due to deposition of silt from the eroding catchment, would have rapidly silted up and become choked with reeds, making it unsuitable for water storage (Rosengren 1973, Bird 1993). It appears that with none of the water-engineering works was there any serious consideration of the natural and economic value of the estuary in its current state, and knowledge of the estuary’s highly significant and unique ecology was effectively non-existent.

Necessaryaction

• Prevent tidal restriction of saltmarsh.• Restore tidal connection to saltmarsh where feasible.

estuary-entrance opening

Opening estuaries during periods of low flow brought about by drought and water extraction upstream can have net ecological benefit if the estuary is cleansed by seawater. There are, however, ‘winners and losers’ among the flora and fauna, and all species need to be considered before taking this action.


The Barwon River mouth is permanently open, so artificial opening is not an issue.

Necessaryaction

• Consider opening estuaries where there is a net ecological benefit. • Apply the Estuary Entrance Management Support System or similar model in deciding on whether to

open an estuary.

weeds

As outlined earlier in Chapter 1, weeds are a major threat to saltmarsh because of their capacity to infiltrate native vegetation and, in some cases, to completely replace it. Lower level or wet saltmarsh presently has few species capable of invading (other than *Spartina: see Chapter 1.11), probably due to lack of introduction of saltmarsh species from outside Australia rather than inherent resistance to weed invasion. *Spartina spp. is a serious weed of wet saltmarsh. Upper level or dry saltmarsh is highly susceptible to weed invasion, particularly from Mediterranean annual grasses such as Sea Barley-grass *Hordeum marinum. A major weed is Tall Wheat Grass *Lophopyrum ponticum, which was introduced to Australia (and promoted) as a salt-tolerant pasture grass, with major management ramifications (Booth et al. 2009). It has invaded many areas in the Connewarre system (Figure 7.13), and is regarded as the most seriously invasive weed of upper saltmarsh in Victoria (Booth et al. 2009; see also Chapter 1.11).


Figure7.13: Gahnia filum sedgeland (left) invaded by Tall Wheat Grass (right), Salt Swamp.

Weed control involving heavy machinery is damaging to saltmarsh. A single inept operation on Spiny Rush *Juncus acutus beside the Werribee River has severely damaged saltmarsh vegetation and permanently jumbled the surface topography of the marsh.

Weeds increased dramatically at The Spit Flora and Fauna Reserve (near Point Wilson) between 1980 and 2002, changing the composition and extent of upper saltmarsh communities. Indigenous saltmarsh annuals have declined alarmingly with most of the 15 species formerly present now extinct. In contrast, the lower or wet saltmarsh has few or no weeds. This change is due to tidal restriction, eutrophic water entering the reserve from the adjacent water treatment plant (both lower salinity) and the withdrawal of sheep grazing (Carr et al. 2002).


Weeds are widespread within the Barwon estuary, but except for *Spartina, are largely confined to upper saltmarsh. *Spartina is scattered within the estuary and is currently being mapped and controlled by Parks Victoria. Parks Victoria is planning to implement control of Tall Wheat Grass at several locations. The biological control agent rust fungus will be applied via spore water to Bridal Creeper in Coastal Alkaline Scrub (EVC 858) at Murtnagurt Swamp.

Necessaryaction

• Undertake weed surveys to locate high-threat weeds.• Undertake weed control programs on target weeds.• Undertake weed control programs to protect sensitive areas.• Ensure control programs use appropriate methods and are cost effective. • Inform the local community to minimise the introduction and spread of weeds.• Implement effective monitoring of weed invasions throughout the area, on public and private land.


pasture ‘improvement’

Pasture ‘improvement’, if it involves introduced salt-tolerant grasses, is a growing issue for the management of many coastal saltmarshes. The problem with the introduction of Tall Wheat Grass *Lophopyrum ponticum has been outlined above.


Tall Wheat Grass is widespread on the edges of the estuary where it is having a major impact, the rare Estuarine Flats Grassland being particularly vulnerable (Figure 7.14).

Figure7.14: Pasture ‘improvement’, Salt Swamp.

Necessaryaction

• Prevent the deliberate introduction of salt-tolerant grasses to estuaries.• Eradicate any infestation before it spreads.• Encourage the use of the indigenous species for production if grazing is unavoidable (on private land).

pest animals

Pest (feral) animals can threaten the wildlife of saltmarsh and estuary habitats, either by direct predation or by habitat modification. A wide range of vulnerable wildlife occurs in such habitats including many waterbirds, Orange-bellied Parrot Neophema chrysogaster, Swamp Skink Egernia coventryi and Southern Brown Bandicoot Isoodon obesulus obesulus. Foxes are the main problem.


Baiting of foxes is being undertaken in the wildlife reserve to protect the Orange-bellied Parrot (Figure 7.15). Rabbits are also baited within the reserve. Feral deer are being controlled within the Reedy Lake area by the Australian Deer Association under the supervision of Parks Victoria.


Figure7.15: Fox baiting to protect Orange-bellied Parrot, lower Barwon River.

Necessaryaction

• Undertake pest animal control as appropriate.• Ensure adequate monitoring of pest animal populations and impacts.

mosquito control

Mosquitoes are a human health issue and a cause of pain and irritation in saltmarsh at times. The most important mosquito in saltmarsh is the Southern Saltmarsh Mosquito Ochlerotatus camptorhynchus, which occurs along the coast of Victoria and is an important vector of Ross River Virus. Insecticides are used to control mosquitoes in Victoria (Department of Sustainability and Environment 2004a).

Mosquitoes are an important part of the aquatic food web, with larvae eaten by fish and adults eaten by birds and bats, but there has been little or no research on the subject. In Victoria, no research has been done on the sensitivity of critical aquatic species to larvicides, the role of mosquitoes in the food web, or the impacts of various forms of habitat modification on saltmarsh characteristics. There has been little research on the environmental impact of control materials and methods under Victorian conditions (Department of Sustainability and Environment 2004a).

Of prime concern is the lack of information on the environmental impacts of treatments on coastal saltmarshes in Victoria, many of which are designated as areas of national and international significance. Data are available from northern states and overseas, but there are no local studies on indicator organisms and ecosystems subjected to physical, chemical and biological intervention for mosquito management. Research on the impacts of control chemicals and other materials on fish species of fresh water and marine environments is also lacking.

Choosing the most appropriate pesticide materials and delivery methods for mosquito management depends on the environmental sensitivity of a site and the area to be treated (Department of Sustainability and Environment 2004a). Bacillus thuringiensis and methoprene (a growth inhibitor for larvae) are recommended for use in areas of very high and high environmental sensitivity. They are the most targeted materials for larval reduction with studies demonstrating minimal impact on a range of non-target species overseas and in


Australia. Larvae ingest these materials over the short time (maybe five days) that they are feeding and fail to develop. Methoprene is used where sites are difficult to monitor and manage and where a longer-term slow-release treatment (over a month) would be more effective (Department of Sustainability and Environment 2004a).

The use of adulticides to treat mosquitoes is not common in Victoria, except in some cases where significant disease outbreaks require rapid reductions in mosquito numbers. The insecticides registered for use in Victoria are mainly malathion and pyrethroids. These chemicals have a more broad-scale impact on non-target species and may have a much smaller impact on overall mosquito numbers than larvicides (Department of Sustainability and Environment 2004a).

Some saltmarshes in Australia and overseas have their surface topography modified in order to reduce mosquito habitat. Runnelling involves linking ponds with the sea enabling better access for predatory fish. It has the potential to modify saltmarsh hydrology, the chemical characteristics of marsh soil, marsh topography, and natural vegetation patterns. Of particular concern is the issue of acid sulfate soils that are found in some estuary sites and that may exposed by channel construction leading to acidification of water (Department of Sustainability and Environment 2004a).


Methoprene is applied to parts of the Barwon River estuary by helicopter.

Necessaryaction

• Follow Departmental guidelines on the application of mosquito insecticides.

stock grazing

Grazing by domestic stock generally has negative effects on saltmarsh: the surface becomes pugged, compacted and lowered in elevation, plants are destroyed or damaged, and weeds may be introduced and spread. Because of their weight, cattle and horses have the greatest impact; sheep usually cause less mechanical damage and soil compaction. Provided the surface topography is not altered and the hydrology is not altered (drains or levees are not constructed), there is considerable potential for the recovery of saltmarsh vegetation following the removal of stock.

Notwithstanding the generally negative impacts of grazing, sheep grazing may lower the intensity of weed infestations by preventing weeds setting seed. Invasion by mediterranean annual weeds at The Spit Flora and Fauna Reserve may be in part due to the removal of sheep grazing. In parts of the reserve, the re-instatement of sheep grazing is likely to control weeds and promote some indigenous species (Carr et al. 2002).


Stock grazing occurs on most of the private land within the Barwon River estuary. There are many examples where the vegetation is severely depleted and, in some cases, destroyed (Figure 7.16). Shrub (Tecticornia spp.)-dominated samphire communities are particularly vulnerable, as the shrubs are brittle and easily destroyed. Their destruction converts Tecticornia shrubland to Sarcocornia or Disphyma herbland and, under the most severe pressure, can result in the total loss of native vegetation and its replacement with introduced species.


In 1983 the exotic annual grasses *Polypogon monspeliensis and *Hordeum marinum were invading bare areas in Salt Swamp where samphire shrubland had been completely destroyed by cattle. There was no sign of samphire recovery. An associated easement for an electric fence had been colonised by these grasses, resulting in their introduction to the central area of the swamp. The easement had left a long-term scar in the vegetation (Yugovic 1985).

Figure7.16: Damage to saltmarsh caused by stock trampling and grazing.

Necessaryaction

• Prevent stock grazing in saltmarsh, except in rare cases where sheep grazing may have a net ecological benefit, for example in terms of weed control.

• Carefully monitor any grazing that is permitted for licensing requirements and to gauge environmental impacts.

shell-grit mining

Shell-grit mining has caused immense damage to the Lonsdale Lakes system, and has permanently destroyed saltmarsh and altered landforms and vegetation patterns. Most mining occurred between 1959 and 1973, when the shell-grit was transported by rail to Melbourne for glass manufacture. Lake Victoria and the area to the north have been particularly affected. There was no attempt to rehabilitate sites by levelling them, so unsightly mounds and bunds now occur throughout the mined areas. The industry was unsustainable; little or no mining of saltmarsh occurs in the area at present, and the last operator will cease operation in 6–12 months.

Despite the extensive destruction of saltmarsh and associated vegetation by shell-grit mining in the Lonsdale Lakes system, mined areas may develop important biodiversity values (see Chapter 1.11). In the proposed Lonsdale Lakes residential development area – formerly mined with seasonal or permanent ponding of saline water – now supports 32 ha of Saline Aquatic Meadow, an endangered EVC in the bioregion (Carr et al.


2005; North et al. 2007). These Saline Aquatic Meadows have the same floristic composition and structure that characterise the rare natural examples: they are dominated by the submerged macrophytes Ruppia spp. and Lepilaena spp. and have no exotic plant species. This situation – saltmarsh destroyed and transformed by shell-grit mining – is analogous to the conversion of saltmarsh to salt production in evaporation pans. These novel systems may have high biodiversity values, particularly as bird habitats.


Shell-grit mining has damaged Salt Swamp and has left numerous scars in the landscape (Figure 7.17; see also Figure 1.34). Murtnagurt Swamp has been severely damaged, with much of the dry saltmarsh destroyed. Salt pans or sparse Sarcocornia herbland now occur where the original saltmarsh existed.

Figure7.17: Scar in saltmarsh vegetation created by shell-grit mining, Salt Swamp.

Necessaryaction

• Protect saltmarsh from all mining activity.• Rehabilitate, where appropriate, those areas that have been mined.

rubbish dumping

Rubbish dumping is often a problem in coastal saltmarsh, especially when the material dumped is hard waste. It is unsightly and may involve the introduction of foreign geological material such as bricks and concrete, as well as posing a pollution threat (Figure 7.18).


Rubbish dumping occurs throughout the Barwon River estuary on private land, presumably by the landowner. Within the reserve, it is a minor but growing issue as residential development expands.

Necessaryaction

• Prevent rubbish dumping within saltmarshes and estuaries.• Remove rubbish where it has been deposited, ensuring that no unacceptable environmental damage

occurs in the process.


Figure7.18: Rubbish dumped on saltmarsh, eastern side of Lake Connewarre.

incursion into public lands

Adjacent landowners may attempt to incorporate public land with saltmarsh or saltmarsh buffer into their property where there is no fencing in the first place, and may install fencing which is not aligned with title boundaries. The process is termed incursion (Figure 7.19).

Figure7.19: Large area of reserve illegally fenced and grazed, Salt Swamp.

ExamplefromBarwonRiverestuary

Some areas of the wildlife reserve are illegally fenced off from the reserve and grazed as if they were private property. On the north shore of Lake Connewarre, one area is included in a private garden where beach sand has been imported, probably killing a mature Boobialla Myoporum insulare in the process.


Some residents in Barwon Heads mow saltmarsh within the reserve adjacent to their property. Another example of incursion in the reserve is more complex: the constructed fence is not aligned with title boundaries, and the net result is that more private land is left outside the fence than public land is included within the fence. Due to resources shortages, Parks Victoria is unable to patrol and review boundaries.

Necessaryaction

• Prevent incursions into reserves.• Fence public land where necessary.• Consider taking no action where, for a particular property, more private land is left outside the fence than

public land is included within the fence. This should be formalised on title if there is any possibility of an adverse possession claim.

unauthorised use

Unauthorised use of saltmarsh becomes an issue when natural values are threatened. Vehicle access, including trailbike access, is highly detrimental to soils and vegetation, and interferes with wildlife.


In at least two cases in the Barwon River estuary, stock have unrestricted access to the wildlife reserve via constructed gates. There is evidence of stock grazing on the edges of the lake inside the reserve. Damage is evident also from unauthorised vehicular access (Figure 7.20).

Figure7.20: Damage to coastal saltmarsh by vehicle access, The Sheepwash.

Necessaryaction

• Prevent unauthorised use of saltmarsh.


boat wash

The wake left by boats may, in some cases, accelerate the erosion of channel banks. Enhanced erosion may result in loss of substrata and saltmarsh vegetation, inhibited recruitment of mangroves and saltmarsh plants, and threats to physical infrastructure.


Boat wash in the Lower Barwon at Barwon Heads (particularly The Sheepwash) is a problem as bank erosion is exacerbated and expensive stabilisation measures have had to be implemented (Figures 7.21 and 7.22). The signposted speed limit of 5 knots is not always observed and is not policed effectively. Parks Victoria is not authorised under the Marine Act 1988 and in any case has no boat in the area; both factors force Rangers to shout at offenders from the river bank. Marine Safety Victoria is currently undertaking a review and may declare Barwon Heads a ‘no wash’ zone, meaning that no boat wake is allowed. A decrease in boat wash could be achieved by lowering the maximum speed limit even further but, as with the current limit, would be ineffective without adequate enforcement.

Figure7.21: Erosion and uprooting of mangroves, The Sheepwash.

Figure7.22: Bank erosion and collapse accelerated by boats, The Sheepwash.

Necessaryaction

• Prevent boat wash by introducing and enforcing boat speed limits.


boardwalks

Boardwalks in less-sensitive areas of coastal wetlands are appropriate to enable people to gain access to areas of saltmarsh, mangrove and estuaries. Access may be desirable for passive recreation (e.g. walking, photography, etc.) or slightly more active pursuits (e.g. fishing). Boardwalks should be elevated structures that do not interfere with water flow, or else the sensitive hydrology and ecology of the vegetation will be compromised. Walking tracks constructed on fill, even with culverts, are not acceptable because they cause significant disruption to the hydrology and thus the vegetation pattern of the marsh. They also create a substratum for weeds. Boardwalks should not be too high above the ground, as this type of construction requires handrails to be installed in accordance with Australian design standards. Handrails on wetland boardwalks conflict with the open landscape and have an over-engineered appearance. There may be a pollution issue also with the materials used to construct boardwalks, especially the leaching of contaminants such as arsenic from treated wood (see Chapter 1.11). Sensitive areas such as lagoons should be avoided to prevent wildlife disturbance. Boardwalks that are well designed in terms of structure, materials and location are appropriate, but poor design can damage or compromise the natural values the boardwalk is meant to allow access to.


The boardwalk at The Sheepwash is a well designed, low but elevated structure (Figure 7.23).

Figure7.23: Well-constructed elevated boardwalk, The Sheepwash.

Necessaryaction

• Undertake detailed site assessment during the design stage to prevent impacts on significant species of vegetation.

• Ensure boardwalks are elevated structures that do not impede water flows.• Avoid sensitive areas, especially lagoons, where wildlife may be disturbed.


signage

In some cases, signs are appropriate to identify reserves, regulate visitor behaviour and inform visitors of the value of reserves. Signage should not be visually intrusive in itself.


Signs are installed at many access points around the reserve, but they are ad hoc, not strategic and, in some cases, have conflicting messages. Some simply state the relevant regulations (Figure 7.24), which may be appropriate in hunting zones, but the existing signs are uninviting to visitors and uninformative about conservation values. Signs on the boardwalk at The Sheepwash, for example, inform visitors about the estuary, but they focus on fauna and contain little or no interesting information on the vegetation. Parks Victoria proposes to review all signage in the reserve.

Figure7.24: Regulations on information sign, Lake Connewarre.

Necessaryaction

• Install signs of suitable design in appropriate locations to identify reserves, regulate visitor behaviour, and inform visitors of the natural value of area under protection.

spread of mangroves

Mangroves are replacing saltmarsh in many places along the New South Wales coast, but the evidence for a similar spread in Victoria is less clear, in part because suitable studies have not been undertaken (Chapter 1.11). The relatively limited and restricted distribution of mangroves in Victoria, which are at their southern geopraphical limit, would mean that the occurrences of encroachment and habitat replacement are few. Interspecies competition provided by Shrubby Glasswort Tecticornia arbuscula would also limit the ability of mangroves to encroach when the stature of plants are similar (Figure 7.25).


As global sea levels are rising, it is anticipated that mangroves in some places along the coast will replace saltmarsh by colonising higher ground. Changes to sedimentation patterns also may affect the relationship between mangrove and saltmarsh. A shift in vegetation is not necessarily a problem where saltmarsh and other types of estuarine wetland have inland areas to which they can migrate, such as within large reserves that lack alienating structures such as sea walls. In more developed regions, however, there are few or no areas for landward migration and saltmarsh may be squeezed out by mangroves on the seaward side. In some cases, mangroves have been planted in areas in which they are not indigenous where they potentially reduce the mudflat foraging area for waterbirds. It is a problem on Mud Islands (Yugovic 1998) and in the Gippsland Lakes (Darcy Duggan, pers. comm.). The Mud Islands population of mangroves is being eradicated by Parks Victoria and the Friends of Mud Islands.

Figure7.25: Shrubby Glasswort Tecticornia arbuscula on the left compared with Avicennia marina on the right. Mangroves would have difficulty in out-competing, encroaching or replacing the saltmarsh in this situation.


Mangroves are spreading dramatically in the Lake Connewarre area (Figure 7.26). Twenty-five years ago they were present only in the tidal delta area as isolated seedlings and stunted shrubs (Yugovic 1985) but now they are abundant and have formed belts along the edges of the delta islands. The change, along with recent dieback of Tangled Lignum Muehlenbeckia florulenta, may indicate rising sea levels.

The lake and island shores of Lake Connewarre have always been wet and tidal, and thus apparently suitable for mangroves in terms of flooding and salinity regimes. Within estuaries mangroves are killed inland by low salinity and frosts, especially at low tide (Ashton 1971). Both limiting factors are likely to become relaxed around the lake as a result of climate change: salinity is higher now because of the decrease in river discharge. The limited water-quality data suggests that the lake has not experienced freshwater conditions in recent years (Dahlhaus et al. 2007).


Figure7.26: Colonising mangroves at the tidal delta, Lake Connewarre.

Necessaryaction

• Do not remove mangroves from sites they colonise naturally.• Monitor the distribution and extent of mangroves and undertake investigations to determine the cause

of mangrove spread where detected. Removal of mangroves where they do not occur naturally may be tackling the symptom rather than the cause and hence generate a non-sustainable course of action.

fencing

Fencing is expensive to construct and maintain and, if possible, is best avoided in order to minimise disturbance and allow wildlife free movement across the landscape. In many situations, however, fencing is necessary to exclude undesirable impacts arising from grazing by domestic stock, vehicle access or pedestrians. Fencing may also be installed to protect regenerating or planted vegetation. The Crown is not obliged to pay for fencing (Fences Act 1968, Section 31).


Fencing has been necessary throughout the Barwon River estuary to exclude domestic stock and vehicles on private land from entering the wildlife reserve (Figure 7.27). Fencing is usually undertaken at the cost of the adjacent landholder, although the Bellarine Ark Project provides some funding.

Protective fencing has been used in the Barwon River estuary to protect naturally established mangrove seedlings and mangroves planted as a result of a development elsewhere on the estuary (Figure 7.28). Parks Victoria undertook fencing in 2002 as part of a project to protect the river bank from erosion and to improve management of pedestrian and recreational fishing access along the river. New boardwalks and fishing platforms were also erected to better manage human pressure on the river.


Figure7.27: An example of effective fencing in restricting stock access along the boundary of the reserve, Hospital Swamp.

Figure7.28: Fencing used to protect mangrove seedlings. The fencing has been successful in not only protecting these mangroves, which have survived quite well, but also assists in increasing community awareness of their value in protecting the river environment.

Necessaryaction

• Construct and maintain fencing to protect natural areas where necessary.• Construct fencing with minimum impact on vegetation.


fire

Fire is rare in saltmarshes but can occur at times, and upper level saltmarsh is most likely to burn (see Figure 1.44). Ongoing and future climate change is likely to see an increased incidence and severity of fire. At The Spit Flora and Fauna Reserve, a fire in 2001 caused high mortality of Gahnia tussocks but reduced the cover of exotic annuals and stimulated the growth of Distichlis and Sarcocornia, which suggests that fire could have a useful role in saltmarsh management (Carr et al. 2002).


Fire is rare within the estuary but does occur occasionally. Fire can move slowly in Gahnia sedgeland, and a spread rate of 1 m min–1 has been observed at Salt Swamp (Yugovic 1985). The fire had been lit by the adjacent farmer within an area of the reserve leased for grazing. Yugovic (1985) showed that grazing of saltmarsh by domestic stock of Gahnia that was regenerating after fire was highly detrimental. A fire originating in Geelong spread into Reedy Lake between 2005 and 2007 (S. Willsher, Parks Victoria, pers. comm.).

Necessaryaction

• Allow fire to burn into saltmarsh; do not construct fire breaks within saltmarsh.• Protect regenerating saltmarsh from disturbance, especially grazing.• Monitor recovery of any burnt saltmarsh vegetation and, in particular, invasion by exotic species or

increases in exotic species.• Undertake weed control if required in fire-affected areas.

visitor management

Visitors are generally desirable around and within saltmarsh and estuary vegetation for community social health and to increase awareness and support for the protection of natural areas. Even so, visitor pressure may need to be managed to prevent impacts on natural features, especially those arising from pedestrian passage through the mangrove or saltmarsh itself. Thus visitor management often requires a range of infrastructure, including fencing, boardwalks and signage.


Boardwalks, signage and fencing are placed at various access points around the wildlife reserve, and is concentrated at The Sheepwash, Barwon Heads. Anglers have access to the river bank by foot and by car. Cars cause problems especially when they become bogged, and physical damage to saltmarsh results during both the bogging itself and the subsequent attempts at recovery.

Necessaryaction

• Undertake measures to manage visitor pressure on natural features.• Provide interpretation material to visitors as appropriate.


regeneration and revegetation

Revegetation projects are often poorly planned, and plantations purporting to be revegetation can consist of non-site indigenous species, in which case they are horticulture and not revegetation. Such failures reflect a general lack of understanding of both saltmarsh ecology and the highly variable and site-specific nature of wetland vegetation. Such plantings usually do poorly or die, with the result that time and resources are wasted, community goodwill exhausted, and the integrity of the site’s ecology is compromised. Revegetation is a last resort to be implemented after all natural recruitment options have been exhausted and should be carried out using strictly site indigenous plant material.


A number of plantations purporting to be revegetation occur within the Barwon River estuary, but few are site indigenous and some include plants not indigenous to the region. There is a general tendency to plant trees and shrubs below their natural zone on sites that are naturally treeless (Figure 7.29). In many cases, this seems to be done in order to provide screening for duck shooting. In one plantation Moonah Melaleuca lanceolata has been planted to provide roosting habitat for Orange-bellied Parrot when the site is below the natural elevation for this species and the plantation is probably doomed in the long term. The site naturally supports the shrub Tangled Lignum Muehlenbeckia florulenta which should have been planted instead. Blue-winged Parrots roost in lignum and the Orange-bellied Parrot is assumed to do likewise. As noted earlier, mangroves have been planted onto the river bank at The Sheepwash, where they are not site indigenous.

Figure7.29: Inappropriate planting of locally indigenous but not site-indigenous species at Salt Swamp, resulting in the almost complete death of young plants.

Revegetation works are often associated with rehabilitation programs, which as mentioned above can often fail without scientific rigour to support the purpose and design of such works. Mangrove and coastal saltmarsh rehabilitation projects have now reached a level of sophistication where success has been achieved, such as the Kooragang Island Restoration Project in Newcastle, NSW. A number of manuals and best-practice guidelines are now available for New South Wales specifically (e.g. Department of Environment and Climate Change


2008a,b) and more generally (Adam 2009b). Similar types of guiding documents need to be made available in Victoria to support both government agencies and the community who are enthusiastic to undertake projects but require guidance to ensure that projects are appropriate, successful and avoid failure.

Necessaryaction

• Facilitate natural regeneration of vegetation.• Undertake revegetation only where natural regeneration cannot occur.• Apply the site-indigenous principle when undertaking revegetation and ensure that the composition and

structure of the vegetation mimics natural models.• Develop best practice guidelines or manuals to assist, facilitate and support rehabilitation projects

involving mangroves and coastal saltmarsh.

wetland construction

Artificial wetlands are sometimes created in coastal saltmarsh to provide habitat for waterbirds, provide hunting opportunities, or as treatment ponds. Often they are created with little or no regard for the existing natural vegetation and topography. In one recent case at Williamstown, rare Tecticornia dry saltmarsh on public land was destroyed for the constructed Paisley-Challis wetlands, allegedly without planning permission. Adding insult to injury, the wetlands are signed as an environment project with several government agencies seeking credit for it. To quote from Hobsons Bay City Council (2008):

A feature of the parklands are the Paisley-Challis wetlands, formed in 2002 by restructuring two stormwater drains to form a filtration wetland, adjacent to the coast. The project embodies principles of multi-objective planning, bioremediation, habitat consolidation and landscape enhancement. And it’s produced a shiny new swamp.

Figure7.30: Outlet structure which controls water levels, Reedy Lake.



Large freshwater wetlands have been created from tidal saltmarsh in the Barwon River estuary to provide duck habitat for hunting. Reedy Lake and Hospital Swamp are managed as freshwater systems, while the attempt at Salt Swamp failed. Levees, channels, inlet and outlet structures and tracks have been constructed but, to date, there has been no excavation of wetland basins (Figure 7.30). The artificial wetlands have held little or no water in recent years due to drought. Waterholes in Salt Swamp were deepened and enlarged when dry to encourage water retention for duck hunting (Dahlhaus et al. 2007).

Necessaryaction

• Prevent construction of ‘wetlands’, especially by excavation, within saltmarsh.

enforcement

A visible presence of management personnel and a willingness to enforce regulations and undertake prosecution, in court if necessary, is beneficial to natural areas.


Limited resources are a problem for agencies such as Parks Victoria, which currently does not have a boat with which to patrol the river and lake.

Necessaryaction

• Enforce regulations and undertake prosecution as necessary.

Documents

7 management template - OzCoasts 7: management template 309 Information on the vegetation ecology and management of the Barwon River estuary is available in Yugovic (1985, 2006), Yugovic