Category Archives: Fauna & habitat

Project Eden: Fauna reintroductions, Francois Peron National Park, Western Australia

Per Christensen, Colleen Sims and Bruce G. Ward

Key words. Ecological restoration, pest fauna control, captive breeding, foxes, cats.

Figure 1. The Peron Peninsula divides the two major bays of the Shark Bay World Heritage Area, Western Australia.

Figure 1. The Peron Peninsula divides the two major bays of the Shark Bay World Heritage Area, Western Australia.

Introduction. In 1801, 23 species of native mammals were present in what is now Francois Peron National Park. By 1990 fewer than half that number remained (Fig 1.). Predation by introduced foxes and cats, habitat destruction by stock and rabbits had driven many native animals to local extinction.

Project Eden was a bold conservation project launched by the WA government’s Department of Conservation and Land Management (CALM -now Dept of Parks and Wildlife) that aimed to reverse extinction and ecological destruction in the Shark Bay World Heritage Area.

The site and program. Works commenced in Peron Peninsula – an approx. 80 km long and 20 km wide peninsula on the semi-arid mid-west coast of Western Australia (25° 50′S 113°33′E) (Fig 1). In the early 1990s, removal of pest animals commenced with the removal of sheep, cattle and goats and continued with the control of feral predators. A fence was erected across the 3km ‘bottleneck’ at the bottom of the peninsula where it joins the rest of Australia (Fig 2) to create an area where pest predators were reduced to very low numbers.

Figure 2. The feral proof fence was erected at the narrow point where Peron Peninsula joins the mainland.

Figure 2. The feral proof fence was erected at the narrow point where Peron Peninsula joins the mainland.

Once European Red Fox (Vulpes vulpes) (estimated at 2500 animals) was controlled and feral Cat (Felis catus) reduced to about 1 cat per 100 km of monitored track, sequential reintroductions of five locally extinct native animals were undertaken (Figs 3 and 4).  These included: Woylie (Bettongia penicillata – first introduced in 1997), Malleefowl (Leipoa ocellata – 1997), Bilby (Macrotis lagotis – 2000), Rufous Hare-wallaby (Lagorchestes hirsutus – 2001), Banded Hare-wallaby (Lagostrophus fasciatus -2001), Southern Brown Bandicoot (Isoodon obesulus – 2006) and Chuditch (Dasyurus geoffroi geoffroi -2011?)

Methods. Cat baiting involved Eradicat® cat baits, which were applied annually during March–April at a density of 10 to 50 baits/km2. Cat baiting continued for over 10 years, supplemented with a trapping program, carried out year round over a 8 -year period. Cat trapping involved rolling 10 day sessions of leghold trapping along all track systems within the area, using Victor Softcatch No. 3 traps and a variety of lures (predominantly olfactory and auditory).Tens of thousands of trap nights resulted in the trapping of up to 3456 animals. Fox baiting involved dispersal of dried meat baits containing 1080 poison by hand or dropped from aircraft across the whole peninsula. Baiting of the peninsula continues to occur annually, and removes any new foxes that may migrate into the protected area and is likely to regularly impact young inexperienced cats in the population, with occasional significant reductions in the mature cat population when environmental conditions are favourable.

Malleefowl were raised at the Peron Captive Breeding Centre from eggs collected from active mounds in the midwest of Western Australia. Woylies were reintroduced from animals caught in the wild from sites in the southwest of Western Australia, with Bilbies sourced from the Peron Captive Breeding Centre, established by CALM in 1996 to provide sufficient animals for the reintroductions. The centre has since bred more than 300 animals from five species

Monitoring for native mammals involved radio-tracking of Bilbies, Woylies, Banded Hare Wallabies, Rufous Hare-Wallabies, Southern Brown Bandicoots, Chuditch and Malleefowl at release, cage trapping with medium Sheffield cage traps and medium Eliots, as well as pitfall trapping of small mammals. The survey method for cats utilized a passive track count survey technique along an 80 km transect through the long axis of the peninsula. The gut contents of all trapped cats were examined.

Fig. 3. Woylies were first introduced in 1997 from animals caught in the wild at sites in southwest Western Australia.

Figure 3. Once foxes were controlled and cats reduced to about 1 cat per 100 km of monitored track, sequential reintroductions of five locally extinct native animals were undertaken. Woylies were first introduced in 1997 from animals caught in the wild at sites in southwest Western Australia.

Once European Red Fox (Vulpes vulpes) (estimated at 2500 animals) was controlled and feral Cat (Felis catus) reduced to about 1 cat per 100 km of monitored track, sequential reintroductions of five locally extinct native animals were undertaken.

Figure 4. Tail tag being fitted to a Bilby. (Bilbies were re-introduced to the Peron Peninsula in 2000, from animals bred in the Peron Captive Breeding Centre.)

Results. Monitoring has shown that two of the reintroduced species – the Malleefowl and Bilby – have now been successfully established. These species are still quite rare but they have been breeding on the peninsula for several years The Woylie population may still be present in very low numbers, but despite initial success and recruitment for six or seven years, has gradually declined due to prolonged drought and low level predation on a small population. Although the released Rufous Hare-wallabies and the Banded Hare-wallabies survived for 10 months and were surviving and breeding well, they disappeared because of a high susceptibility to cat predation and other natural predators like wedge-tailed eagles. Although some predation of Southern Brown Bandicoot has occurred and the reintroduction is still in the early stages, this species has been breeding and persisting and it is hoped that they will establish themselves in the thicker scrub of the peninsula.

Lessons learned. We found that the susceptibility to predation by cats and foxes varies considerably between species. Malleefowl are very susceptible to fox predation because the foxes will find their mound nests, dig up their eggs up and eat them – consequently wiping them out over a period of time. As cats can’t dig, Malleefowl can actually exist with a fairly high level of cats. Bilbies live in their burrows and are very alert so they can persist despite a certain level of cats. But the Rufous Hare-wallaby and the Banded Hare-wallaby are very susceptible to cat predation and fox predation due to their size and habits.

Examination of the period of time when species disappeared from the Australian mainland showed that there was a sequence of extirpations, reflecting the degree to which the species were vulnerable to pest predators. The ones that survived longest are those that are less vulnerable. This suggests that if complete control of predators is not possible (considering cat control is extremely difficult), it is preferable to focus on those animals that are least vulnerable. While it could be argued that reintroductions should be delayed until such time as all the cats and foxes have been removed, such a delay (which might take us 10, 20 or even 100 years) is likely to exceed the period of time many of these species will survive without some sort of assistance. It is likely to be preferable to proceed with reintroductions although we might be losing some animals.

Future directions. As with the majority of mainland reintroduction projects, level of predator control is the key to successful establishment of reintroduced fauna. The Project is currently under a maintenance strategy and future releases, which included the Western Barred Bandicoot (Perameles bougainville), Shark Bay Mouse (Pseudomys fieldi), geoffroi), Greater Stick-nest Rat (Leporillus conditor) and Red-tailed Phascogale (Phascogale calura) are on hold until improved cat control techniques are available. Despite the uncertain future for reintroductions of these smaller species, ongoing feral animal control activities and previous reintroductions have resulted in improved conditions and recovery for remnant small native vertebrates (including thick billed grass wrens, woma pythons and native mice), and new populations of several of the area’s threatened species which are once again flourishing in their original habitats.

Acknowledgements: the program was carried out by Western Australia’s Department of Parks and Wildlife and we thank the many Departmental employees, including District and Regional officers for their assistance over the years, and the many, many other people that have volunteered their time and been a part of the Project over the years, for which we are very grateful.

Contact: Colleen Sims, Research Scientist, Department of Parks and Wildlife (Science and Conservation Division, Wildlife Research, Wildlife Place, Woodvale, WA 6026, Australia, Tel: +61 8 94055100; Email: colleen.sims@dpaw.wa.gov.au). Also visit: http://www.sharkbay.org.au/project-eden-introduction.aspx

Further detail and other work in WA:

Per E. S. Christensen, Bruce G. Ward and Colleen Sims (2013) Predicting bait uptake by feral cats, Felis catus, in semi-arid environments. Ecological Management & Restoration 14:1, 47-53.

Per Christensen and Tein McDonald (2013) Reintroductions and controlling feral predators: Interview with Per Christensen. Ecological Management & Restoration, 14:2 93–100.

 

Tasmanian Northern Midlands Restoration Project

Neil Davidson

Introduction. The Midlands Restoration Project is a long-term (multi decade) landscape-scale environmental restoration initiative designed to increase connectivity and biodiversity in the Northern Midlands, an area with a long history of agricultural production. It is intended to provide a demonstration of how strategic native vegetation restoration at an industrial scale can reconnect native animal habitat in a fragmented agricultural landscape.

Design of the project complies with the Conservation Action Plan for the biodiversity hotspot and ecological models that identified optimum pathways to reconnect existing vegetation remnants through ‘corridors’ and ‘stepping stones’, to improve habitat and facilitate the movement of native mammals and birds across the landscape from the Eastern Tiers to the Central Highlands and provide better resilience to predicted climate change impacts.

The landscape and its ecosystems. The Tasmanian Northern Midlands is recognised as being one of Australia’s 15 “Biodiversity Hotspots” – a place with exceptionally high numbers of native plant and animal species. Although over half of Tasmania’s land area is protected in national parks and reserves, the Northern Midlands biodiversity hotspot is mostly on private land, not formally protected, and its natural values are in a state of decline – with real risks of further species extinctions.

The low dry landscapes in the Midlands of Tasmania are predominantly privately owned and have been farmed for more than 200 years. The distinctive dry native vegetation communities are now present as small fragments in a sea of intense agricultural production. Most remnant patches are degraded through loss of understorey, tree decline and invasion by exotic weeds, and are at greater risk of further decline as a result of climate change. A consequence of this is that habitat values for native fauna are compromised, leading to fewer types and numbers of animals present.

Macquarie River near Ross: Part of the Ross wildlife corridor in the early stages of revegetationPhoto taken in June 2014

Fig 1. Macquarie River near Ross: Part of the Ross wildlife corridor in the early stages of revegetation. (Photo taken in June 2014.)

Aims and objectives. The aim of the project is to reverse the decline in species richness and habitat values in the Tasmanian Midlands biodiversity hotspot.  A primary objective is to re-establish functional connectivity for native mammals (quolls, bandicoots, bettongs, Tasmanian devils, bats) and woodland birds in the Northern Midlands, where less than 10% of native vegetation and less than 3% of native lowland grasslands remain.

Specifically the project aims to restore 6,000ha in two wildlife corridors across the Northern Midlands. We are doing this by strategic restoration using local native species to buffer and connect existing vegetation through the construction of two wildlife corridors, the Ross Link and Epping Forest Link (see Figs 1 and 2).

Map 1: Biodiversity Corridors in the Tasmanian Northern Midlands

Figure 2. Biodiversity Corridors in the Tasmanian Northern Midlands

Works to date. The first 1,000ha in Stage 1 is nearly complete, with 200,000 native plants planted in more than 600ha of grassy woodland and riverflats, and a further 400ha of existing native vegetation being secured for conservation purposes. We are currently planning Stage 2 of the project, to revegetate a further 5,000ha, including 1,000ha of riverine revegetation to complete the two corridors.

We are employing two revegetation approaches to best suit the open grassy woodland and river system landscapes:

  1. Woodland restoration: so far we have buffered and restored 410ha of native woodland remnants near Ross and Cressy. The wide-spaced plantings recreate an open grassy woodland suitable for more mobile animals and birds (Fig 3) .
  2. Riparian restoration: to date we have replanted 16km of the banks of the Macquarie River, Isis River and Tacky Creek (>200ha) with local native riparian plants. These are dense plantings (625 to 830 stems/ha) that provide habitat for less mobile and secretive animals and birds. Our Macquarie riparian restoration work is recognised as being currently the largest riverine revegetation project in Australia.
Grassy woodland restoration at ‘Connorville’. Caged trees & shrubs planted August 2014 – photo May 2015

Fig 3. Grassy woodland restoration at ‘Connorville’. Caged trees and shrubs planted August 2014 – photo May 2015

Fig 4.Tas Midlands

Fig. 4. Some of the important plant and animal species in the biodiversity hotspot.

Science. The project has strong scientific support from the University of Tasmania (UTAS), where Greening Australia is an industry partner for three Australian Research Council (ARC) supported research projects embedded in our revegetation and restoration activities:

  1. Professor Brad Potts is leading a large scale field experiment investigating whether it’s best to use local native provenance eucalyptus seed or seed collected from elsewhere for restoration plantings in an area already experiencing climate change;
  2. Associate Professor Menna Jones’s team is researching midlands native mammal and bird populations, how they move across fragmented agricultural landscapes and their habitat preferences; and,
  3. The new ARC Centre for Forest Value, where students are currently being selected and the projects are being determined.

Through these research projects we have more than 15 PhD candidates and post-doctorate staff assisting us to better design and undertake our on-ground restoration activities. In addition to the UTAS projects we have research trials underway to improve tree and shrub direct seeding and native grass seeding methodologies.

Cultural restoration. Whilst we place a high emphasis on ecological restoration in the midlands, we recognise that we must engage with the people in the landscape and their enterprises. In order to effectively communicate and engage with the local and Tasmanian communities and visitors we are working with artists, schools, businesses and Aboriginal people to better interpret the natural environment and involve them in our restoration activities.

We recognise the importance of supporting vibrant and profitable agricultural and rural businesses and complementing commercial enterprises in the midlands at the same time as improving the natural values and ecosystem wellbeing across the landscape.

Education. Greening Australia employs a teacher on an education project associated with the Midlands Restoration Program. The teacher works with the local Oatlands, Campbell Town and Cressy District schools and several urban schools to engage local and city children and communities in all aspects of the restoration project. The education program aligns with the Australian Curriculum across all subject areas and provides students with a great link between indoor and outdoor learning.

Landscape artworks. The University of Tasmanian College of the Arts is currently conducting a pilot landscape arts project to engage local schools and township communities in developing sculptural artworks to be placed in the landscape. The artworks will include functional features that are beneficial for native animals, which may include nesting hollows and/ or bird perches.

The project’s principle financial supporters in Stage 1 have been the Australian Government, the Ian Potter Foundation, John Roberts Charitable Trust, the ARC Linkage program, Pennicott Wilderness Journeys, Targa Australia, Stornoway, Dahl Trust, and the Foundation for Rural and Regional Renewal.

Future directions. In order to complete Stage 2 of the project (to restore a further 5,000ha in wildlife corridors across the midlands) we need to raise AUD$25m. Work is underway on landscape planning, community consultation, landholder engagement and the establishment of a fundraising campaign. We expect that the Tasmanian midlands will be transformed in the next five years, with two green bands of native vegetation connecting the Western Tiers to the Eastern Tiers and measurable improvements in native fauna habitats and populations.

Project partners. Greening Australia is working in partnership with many individuals and organisations to deliver the project and associated scientific research. Delivery partners include midland farmers, the Tasmanian Land Conservancy, Bush Heritage Australia, Australian Conservation Volunteers, Green Army program, Department Primary Industry Parks Water and Environment, UTAS, NRM North, CSIRO, Tasmanian Farmers and Graziers Association, Northern Midlands Council, Department of Education and Independent Schools.

Contact. Neil Davidson, Restoration Ecologist (Greening Australia) and Adjunct Senior Lecturer,  School of Biological Sciences, University of Tasmania, Sustainability Learning Centre, 50 Olinda Grove, Mt Nelson 7007,
GPO Box 1191, Hobart, TAS 7001 Australia. Tel: +61 (0)3 6235 8000 Mobile; 0427 308 507 . Web:  www.greeningaustralia.org.au

Peniup Ecological Restoration Project

Justin Jonson

Key words: reconstruction, planning, direct seeding, monitoring, innovation

Introduction. The Peniup Restoration Project was initiated in 2007, when Greening Australia and Bush Heritage Australia jointly purchased a 2,406 hectare property as a contribution to the conservation and restoration objectives of Gondwana Link. The property has an average annual rainfall of approximately 450mm per year and had previously been farmed in a traditional broad acre sheep and cropping rotation system. The site is located within a highly diverse mosaic of varying soils and associated vegetation associations across Mallee, Mallee Shrubland, and Woodland type plant communities.

Planning and 2008 Operational Implementation. In 2008, Greening Australia’s Restoration Manager Justin Jonson developed a detailed ecological restoration plan for 950 hectares of cleared land on the northern section of the property. Information and procedures applied for that work are detailed in the EMR Journal article Ecological restoration of cleared agricultural land in Gondwana Link: lifting the bar at ‘Peniup’ (Jonson 2010). Further information is also available for the specific vegetation associations established via the Peniup Restoration Plan, with species lists according to height stratum, including seedlings planted by hand which were nitrogen fixing or from the Proteaceous genera. Funding for the initial 250 hectares of restoration were raised and the project implemented in 2008 (Fig.1).

Figure 1. Map showing the 2008 operational areas at Peniup with replanted communities replanted by direct seeding, and GPS locations of permanent monitoring plots (n=42), patches of hand planted seedlings (n=31) and seed (n=61), pre-planning soil sampling sites (n=115) and contour oriented tree belts to ensure establishment across the site (direct seeded understory consistently here).

Figure 1. The 2008 operational areas at Peniup showing communities replanted by direct seeding, and GPS locations of permanent monitoring plots (n=42), patches of hand planted seedlings (n=31) and seed (n=61), pre-planning soil sampling sites (n=115) and contour oriented tree belts to ensure establishment across the site.

Figure 2: Map showing GPS locations of permanent monitoring plots established at Peniup.

Figure 2. Location of 42 Permanent Monitoring Plots established in 2008 Peniup Ecological Restoration Project. Recruits from the direct seeding were measured 5 months after implementation, and then annually to assess persistence and long term development

Monitoring. A total of 42 monitoring plots were laid out across seven of the nine plant communities established (Fig.2). Details of the methodology, results and ongoing evaluation have been published (Jonson 2010; Hallet et al. 2014; Perring et al. 2015).

Results to date.  Monitoring indicates approximately 3.8 million plants were re-established by the direct seeding across the 250 hectare project area.  The numbers established in each plant community are shown in Fig.3 and represent the majority of plant species in each reference model. After 8 years it is clear that the project’s objectives are on track to being achieved, considering: a) absence of agricultural weeds; b) nutrient cycling through build up and decomposition of litter and other detritus;  seed-rain by short-lived nitrogen-fixing Acacia shrubs, c) diverse structural development of re-establishing species; and,  d) presence of many target animals using the site. Peniup’s progress in terms of recovery of the National Restoration Standards’s 6 ecosystem attributes is depicted and tablulated in Appendix 1.

Figure 3: Chart showing per hectare estimates of plant establishment counts by restoration plant community.

Figure 3. Per hectare estimates of Peniup plant establishment counts by restoration plant community.

Figure 4. Photo of riparian/drainage Tall Yate open woodland community with mid and understory shrubs and mid-story trees.

Figure 4. Riparian/drainage Tall Yate open woodland community at Peniup – with mid and understory shrubs and mid-story trees.

Innovation. As an adaptive management approach, small, discrete patches of seedlings of the proteaceous family were hand planted to make best use of small quantities of seed. Planting of these 5,800 seedlings in small patches, termed ‘Nodes’, provided further resource heterogeneity within relatively uniform seed mixes (by soil type). The impetus for this approach was to create concentrated food sources for nectarivorous fauna, while increasing pollination and long-term plant species viability (Jonson 2010).

Figure 5. Map showing distribution of Proteaceous Nodes.

Figure 5. Distribution of Proteaceous Nodes.

Lessons learned. Continuity of operational management is a critical component to achieving best practice ecological restoration. Project managers must be involved to some degree in all aspects of works, because flow on consequences of decisions can have high impact on outcomes. Detailed planning is also needed with large scale projects; otherwise the likelihood of capturing a large percent of site specific information is low. Finally, the use of GIS software for information management and site design is an absolute necessity.

Figure 6. Photo showing Banksia media and Hakea corymbosa plants with seed set.

Figure 6. Banksia media and Hakea corymbosa plants with seed set after 5 years.

Figure 7. hoto showing bird nest built within re-establishing Yate tree at Peniup within 5 years.

Figure 7. Bird nest within 5-year old Yate tree at Peniup.

Figure 8. Photo showing ecological processes in development including, a) absence of agricultural weeds, b) nutrient cycling and seed-rain deposition by short-lived nitrogen-fixing Acacia shrubs, c) diverse structural development of re-establishing species, and d) development of leaf litter and associated detritus for additional nutrient cycling.

Figure 8.  Five-year-old vegetation is contributing to a visible build up of organic matter and decomposition is indicating cycling of nutrients.

Stakeholders and Funding bodies. Funding for this Greening Australia restoration project was provided by The Nature Conservancy, a carbon offset investment by Mirrabella light bulb company, and other government and private contributions.

Contact information. Justin Jonson, Managing Director, Threshold Environmental, PO Box 1124, Albany WA 6330 Australia, Tel:  +61 427 190 465; jjonson@thresholdenvironmental.com.au

See also EMR summary Monjebup

See also EMR feature article Penium project

Watch video: Justin Jonson 2014 AABR presentation on Peniup

Appendix 1. Self-evaluation of recovery level at Peniup in 2016, using templates from the 5-star system (National Standards for the Practice of Ecological Restoration in Australia)

Fig 9. Peniup recovery wheel template

Evaluation table2

Piccaninnie Ponds Conservation Park, South Australia

Mark Bachmann

Key words: wetland restoration, Ramsar, rising springs, drainage, hydrology

Piccaninnie Ponds Conservation Park is situated 30 km south east of Mt Gambier in South Australia. For 15-20 years after the park was proclaimed in 1969, there was considerable local interest in trying to address previous changes that had been made to the hydrology of the wetland system.

Although it was protected, reserved and supporting a diverse suite of habitats and range of resident threatened species, Piccaninnnie Ponds was far from intact from a hydrological perspective. Prior to European settlement, water that discharged from the karst, rising-spring wetlands in the system flowed eastward across the State border into the Glenelg River Estuary, in far South West Victoria.

This is how the system remained until 1906, when the first of several attempts to drain the wetlands of Piccaninnie Ponds directly to the sea occurred. What ensued was a turbulent 9 year period during which the fishermen successfully lobbied to have the creek re-directed to the Glenelg River in 1915; a step which was ultimately unpopular with affected landholders and resulted in an alternative flow path again being cut to the sea two years later in 1917. Subsequent ad hoc drainage and development of portions of the wetland system continued and by the time the Piccaninnie Ponds Conservatioon Park was proclaimed in 1969, a new main artificial outlet drained the ponds directly to the sea.

The first attempts at advocacy to restore environmental flows to the Glenelg River in the 1970s and 80s to counter this long-term drying trend in the Park were unsuccessful, until the concept was revisited and a series of steps undertaken, starting in 2001, to achieve hydrological restoration. These steps culminated in the following actions.

 Fig. 1 – Stage 1 weir and fishway under construction in 2006.

Fig. 1,  Stage 1 weir and fishway under construction in 2006.

Actions taken to correct hydrology

  1. 2006 – Stage 1 weir and fishway constructed at Piccaninnie Ponds (Figure 1) regulated outflows on the artificial outlet. This had the effect of increasing inundation in a small area immediately upstream of the structure, under the direct influence of the weir pool created by the new structure, as shown in Fig 2.
  2. 2013 – The stage 2 weir and fishway upgrade (Fig 3) resulted in the structure height being lifted to increase future management flexibility, including providing the future ability to completely block outflows, should the option of re-instating the original flow path one day become a reality.

The stage 2 upgrade was completed at the same time as providing a new flow path to physically reconnect the isolated eastern and western basins at Piccaninnie Ponds. These wetlands had been separated for several decades by a combination of lower water levels, sand drift and the impact of the Piccaninnie Ponds Road. An aerial photographic view of the new flow path is shown in Fig 4.

These works within the original Conservation Park, have occurred in in a complementary way with those that have occurred in the neighbouring, newly reserved area at Pick Swamp, each contributing to the wider vision for restoration of this wetland complex.

Fig. 2. Drained condition of habitat in 2006

Fig. 2a. Drained condition of habitat upstream of the Stage 1 weir (prior to construction  in 2006).

Fig. 3. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Fig. 2b. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Results to date.

  • Increase in quality and area of available habitat for native freshwater fish, including the nationally threatened Dwarf Galaxias (Galaxiellla pusilla)
  • Protection of hydrological processes that support a wide range of other threatened species, from a number of taxonomic groups
  • A positive trajectory of change in the distribution of wetland habitats in the vicinity of the works (increased aquatic habitat and reversal of a drying trend that was causing terrestrialisation of vegetation communities)
  • Re-establishment of connectivity between the western and eastern wetlands in the Park for the first time in several decades
Figure 4 – The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig. 3. The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig 5a. Piccaninnie

Fig. 4a. Before works – in January 2003

Figure 5 – TOP – Before works image: January 2003. BOTTOM – Post-construction/restoration image: January 2014.

Fig, 4b. After construction/restoration – in January 2014.

Future directions. The works and outcomes described here were delivered by staff working for the South Australian Department of Environment, Water and Natural Resources (DEWNR)

  • Ongoing management of the works and associated ecological monitoring in Piccaninnie Ponds Conservation Park is managed by DEWNR
  • Nature Glenelg Trust staff continue to provide specialist ecological advice and monitoring for the site when required by the site manager, DEWNR

Acknowledgements. The outcomes of the restoration project described can be attributed to a wide range of people who, in addition to the author (see current contact details below), worked at the South Australian Department of Environment, Water and Natural Resources during the period described. DEWNR project ecologists overseeing the works described here include Ben Taylor (stage 1 weir) and Steve Clarke (stage 2 weir and associated works).

The project was generously funded and supported by a range of different grants and programs administered by the South Australian Government, Australian Government and the South East Natural Resources Management Board.

Contact. Mark Bachmann. Nature Glenelg Trust, PO Box 2177, Mt Gambier, SA 5290 Australia; Tel +61 (0)8 8797 8181; Mob+61 (0) 421 97 8181; Email: mark.bachmann@natureglenelg.org.au Web| www.natureglenelg.org.au

See also:

Bradys Swamp EMR short summary

Long Swamp EMR short summary

Long Swamp, Discovery Bay Coastal Park, Victoria

Mark Bachmann

Key words: wetland restoration, Ramsar, hydrology, Glenelg River, drainage

Long Swamp is a 15 km long coastal freshwater wetland complex situated in Discovery Bay Coastal Park, approximately 50 km north-west from Portland in south-western Victoria. The wetland system supports a diverse suite of nationally threatened species and is currently undergoing a Ramsar nomination process. Despite its size, reserved status and impressive biodiversity values, including recognition on the Directory of Important Wetlands in Australia, the local community in Nelson had expressed concern for over a decade about the impact that two artificial outlets to the ocean were having on wetland condition. The outlets were cut during an era when the swamp was grazed, many decades before being dedicated as a conservation reserve in the 1970s.

The wetland originally discharged into the ocean via Oxbow Lake and the Glenelg River mouth at Nelson. These changes to hydrology caused an interruption of flows, contributing to a long-term drying trend within the wetland complex.    This was not immediately obvious to many as the gradual drying of wetlands in a natural area is often less noticeable than in a cleared agricultural area, driven by a seamless and gradual shift towards more terrestrial species within the composition of native vegetation (Fig. 1).

Figure 1. Shrub (Leptospermum lanigerum) encroachment into sedgeland underway in Long Swamp.

In 2012, Nature Glenelg Trust (NGT) became actively involved in Long Swamp, working closely with Parks Victoria, the Nelson Coast Care Group, and the Glenelg Hopkins CMA. The initial involvement was to undertake a scientific review of the aquatic ecological values that might be impacted by the ecological shifts anecdotally observed to be underway. This early work identified that the more remote artificial outlet to the sea (White Sands) had in fact naturally closed, with a dune forming in front of the former channel several years earlier during the Millennium Drought (c. 2005). This formed an area of aquatic habitat immediately upstream of the former outlet that is now home to a diverse native freshwater fish community, including two nationally threatened fish species, the Yarra Pygmy Perch (Nannoperca obscura) and Dwarf Galaxias (Galaxiella pusilla). This observation and other investigations led to the planning of a restoration trial aimed at regulating or possibly blocking the second and final artificial outlet at Nobles Rocks to increase the availability, diversity and connectivity of aquatic habitats throughout Long Swamp, in order to benefit a wide range of wetland dependant species.

As well as undertaking basic monitoring across a broad range of taxonomic groups (birds, vegetation, frogs), the project has a particular emphasis on native freshwater fish populations as a primary indicator of project success.

Figure 2 – Aerial view of Nobles Rocks artificial outlet, detailing the location of the three trial sandbag structures.

Figure 2 . Aerial view of Nobles Rocks artificial outlet, detailing the location of the three trial sandbag structures.

Figure 3 - NGT staff members celebrate the completion of the third and final sandbag structure with some of the many dedicated volunteers from the local community.

Figure 3. Nature Glenelg Trust staff members celebrate the completion of the third and final sandbag structure with some of the many dedicated volunteers from the local community.

Reversal of artificial outlet impact over three phases.

The first two stages of the restoration trial in May and July 2014 involved 56 volunteers from the community working together to construct low-level temporary sandbag structures, initially at the most accessible and technically feasible sections of drain under flowing conditions. Tackling the project in stages enabled us to learn sufficient information about the hydrological conditions at the site in 2014, before commencing the third and final stage of the trial in March 2015. On the 27th April 2015, the main structure was completed, following two days of preparation and nine days of sandbagging (using about 6,600 sandbags), which were put in place with the dedicated help of over 30 volunteers (see Figs 3 and 4). To achieve our target operating height, the structure was raised by a further 30 cm in August 2015.

A series of gauge boards with water depth data loggers were also placed at key locations in the outlet channel and upstream into Long Swamp proper, to monitor the change in water levels throughout each stage of restoration and into the future.

Fig 4a. Long swamp

Figure 4a. View of the Phase 3 Restoration Trial Structure location prior to construction in March 2015.

Fig 4b. Long swamp

Figure 4b. Same location in June 2015, after construction of the Restoration Trial Structure.

Results to date.

Water levels in the swamp immediately upstream of the final structure increased, in the deepest portion of Long Swamp, from 34 cm (in April 2015) to 116 cm (in early September 2015). Further upstream, in a shallower area more representative of the impact on Long Swamp in the adjacent wider area, levels increased from being dry in April 2015, 14 cm deep in May, through to 43 cm deep in early September 2015, as shown in Figure 5. This is a zone where the shrub invasion is typical of the drying trend being observed in Long Swamp, and hence will be an important long-term monitoring location.

To evaluate the response of habitat to short and longer-term hydrological change, we also undertook longer-term landscape change analysis through GIS-based interpretation of aerial photography. This showed that we have currently recovered approximately 60 hectares of total surface water at Nobles Rocks, not including larger gains across downstream habitats as a result of groundwater mounding, sub-surface seepage and redirected surface flows that have also been observed.  These initial results and longer-term outcomes for targets species of native plants and animals will be detailed fully in future reports.

Fig 5a. Long swamp

Figure 5a. Further inland in the swamp after the Phase 3 structure was complete, shown here in May 2015. Depth – 14 cm.

Fig 5b. Long swamp

Figure 5b. Same photopoint 4 months later in September 2015. Depth – 43 cm.

Lessons learned and future directions.Meaningful community participation has been one of the most critical ingredients in the success of this project so far, leading to a strong sense of shared achievement for all involved. Monitoring will continue to guide the next steps of the project, with the ultimate aim of informing a consensus view (among those with shared interest in the park) for eventually converting the trial structure to a permanent solution.

Acknowledgements. Project partners include Parks Victoria, Nelson Coast Care Group, the Glenelg Hopkins CMA and the Friends of the Great South West Walk. Volunteers from several other groups have also assisted with the trials. Grant funding was generously provided by the Victorian Government.

Contact. Mark Bachmann, Nature Glenelg Trust, PO Box 2177, MT GAMBIER, SA 5290 Australia, Tel +61 8 8797 8181, Mob 0421 97 8181, Email: mark.bachmann@natureglenelg.org.au  Web: www.natureglenelg.org.au

See also:

Video conference presentation

NGH newsletter – including a link to a video on the project

Bradys Swamp EMR short summary

Picanninnie Ponds EMR short summary

 

Brady Swamp wetland complex, Grampians National Park, Victoria

Mark Bachmann

Key words: wetland restoration, Wannon River, hydrology, drainage, Gooseneck Swamp

A series of wetlands associated with the floodplain of the Wannon River (Walker, Gooseneck, and Brady Swamps), situated approximately 12 km north east of Dunkeld in western Victoria, were partially drained from the 1950s onwards for grazing purposes (Fig 1). A portion of these wetlands was later acquired and incorporated into the Grampians National Park (and other peripheral reserves) in the mid-1980s, managed by Parks Victoria. However, the balance of the wider wetland and floodplain area remained under private ownership, creating a degree of uncertainty surrounding reinstatement of water regime – an issue that was left unresolved for over two decades.

Many years of planning work, including modelling studies and biological investigations by a range of organisations, never quite managed to adequately resolve the best way to design and progress wetland restoration work in this area. To address the impasse, at the request of the Glenelg Hopkins CMA in early 2013, Nature Glenelg Trust proposed a staged restoration trial process which was subsequently agreed to by landowners, neighbours, government agencies, and local community groups.

Figure 1. Image from the present day: showing artificial drains (red lines/arrows) constructed to drain Walker, Gooseneck and Brady Swamps, as it operated from the 1950s–2013.

Figure 1. Image from the present day: showing artificial drains (red lines/arrows) constructed to drain Walker, Gooseneck and Brady Swamps, as it operated from the 1950s–2013.

Trials and permanent works undertaken.

Initial trials. The restoration process began in August 2013 with the installation of the first trial sandbag weir structure to regulate the artificial drain at Gooseneck Swamp. Its immediate success in reinstating wetland levels led to similar trials being initiated at Brady Swamp and Walker Swamp (Fig. 2) in 2014.

Figure 2. The volunteer sandbagging crew at the artificial drainage outlet from Walker Swamp - August 2014.

Figure 2. The volunteer sandbagging crew at the artificial drainage outlet from Walker Swamp – August 2014.

Permanent works were ultimately undertaken to reinstate the breached natural earthen banks at Brady and Gooseneck Swamps (Figure 3), implemented by Nature Glenelg Trust in early 2015.

Figure 3a. Trial Structure on the Brady Swamp outlet drain in 2014

Figure 3b. The same view shown in Figure 3a, after the completion of permanent works in 2015

Results. The works have permanently reinstated the alternative, original watercourse and floodplain of the Wannon River, which now activates when the water levels in these wetlands reach their natural sill level. This is predicted to have a positive impact on a wide range of flora and fauna species.

Monitoring is in place to measure changes to vegetation and the distribution and status of key fauna species, such as waterbirds, fish and frogs. Due to drought conditions experienced in 2015, to is too early to describe the full ecological impact of the works at this time.

4. Gooseneck Swamp in Sept 2014: the second season of the restoration trial, just prior to the implementation of permanent restoration works

Figure 4. Gooseneck Swamp in Sept 2014: the second season of the restoration trial, just prior to the implementation of permanent restoration works

Lessons learned. The success of these trials has been based on their tangible ability to demonstrate, to all parties involved, the potential wetland restoration outcome for the sites; made possible by using simple, low-cost, impermanent methods. To ensure the integrity of the trial structures, the sandbags used for this purpose are made of geotextile fabric, with a minimum field service life of approximately 5 years.

The trials were critical for building community confidence and collecting real operational data for informing the development of longer-term measures to increase the depth and duration of inundation.

A vital aspect of the trials has been the level of community participation, not only at the sandbagging “events”, but also the subsequent commitment to ecological monitoring, for helping evaluate the biological impacts of hydrological reinstatement. For example, the Hamilton Field Naturalists Club has been undertaking monthly bird monitoring counts that are helping Nature Glenelg Trust to develop a picture of the ecological value of these wetlands and their role in the wider landscape, including the detection of international migratory species.

Acknowledgements. Project partners include Parks Victoria, Hamilton Field Naturalists Club, the Glenelg Hopkins CMA, Macquarie Forestry and other private landholders. Volunteers from several other groups have also assisted with the trials. Grant funding was generously provided by the Victorian Government.

Contact. Mark Bachmann, Nature Glenelg Trust, PO Box 2177, MT GAMBIER, SA 5290 Australia. Tel +61 8 8797 8181, Mob 0421 97 8181; Email mark.bachmann@natureglenelg.org.au. Web| www.natureglenelg.org.au

See also:

Long Swamp EMR short summary

Picanninnie Ponds EMR short summary

Victorian Northern Plains Grasslands Protected Area Network: formation and future management

Nathan Wong

Key words: ecosystem decline, conservation planning, grassland restoration, threatened species

Building the network. Since the early 1990s Trust for Nature (Victoria) (TfN) in partnership with State and Federal government agencies and local land owners have been working to protect, restore and improve the condition and extent of Grasslands in the Victorian Riverina. This critically endangered ecosystem has been degraded, fragmented, and cleared over the past 200 years by a range of impacts largely associated with the exploitation of these areas for agricultural production. This use has resulted in the loss of over 95% of the original grassland extent in Victoria and the degradation of all remaining remnants.

The first major achievement of this program occurred in June 1997 when Trust for Nature acquired the 1277 ha ‘Davies’ property following many years of negotiations. This land was transferred to the Crown in April 1999 to form the Grassland section of what is now Terrick Terrick National Park. Since this initial acquisition a significant number of purchases have been added to the public estate with the support of both State and Federal National Reserve Systems Programs. These additions have resulted in Terrick Terrick National Park now covering over 3334ha (Table 1) and the establishment of Bael Bael Grasslands NCR during 2010 and 2011 which now covers 3119ha.

Running concurrently with this increase in the public estate has been a program to build and secure private land under conservation covenant as well as Trust for Nature establishing a number of reserves to build its private reserve network in the Victorian Riverina. These efforts have resulted in the addition of 2804ha owned by Trust for Nature, including Glassons Grassland Reserve (2001), Kinypanial (1999), Korrak Korrak (2001), Wanderers Plain (2009-2010) and 1036ha of private land protected under conservation covenant.

As a result of these efforts the area of grasslands within the Protected Area Network in the Victorian Riverine Plains has grown from virtually nothing in the mid-1990s, to in excess of 10,000ha and continues to expand.

OLYMPUS DIGITAL CAMERA

Fig 1. Very high quality Northern Plains Grasslands in Spring, note the inter-tussock spaces and diversity of flowering herbs (Photo: Nathan Wong).

Table 1. Acquisitions that have resulted in Terrick Terrick National Park, now covering over 3334ha.

Table 1

Current remnant condition. Whilst these grasslands are the best examples of the remaining ecosystem and protected under State and Federal government legislation, all of them have been degraded by past land-use. Therefore the need to not only protect but restore them is critical to the successful management of these systems in-perpetuity. Despite this past loss of a range of grazing-sensitive plant species many still persist in small isolated populations across the reserve network. Management of grazing, when it is applied, to ensure that continued losses do not occur whilst maintaining biodiversity values is one of the key aims of management. As a result of loss of quality, quantity and fragmentation of habitats, a range of important faunal species have also historically declined (Figs 2 & 3).

Need for management and restoration. There is great potential for management regimes to manipulate the composition of grasslands to enhance the likelihood of restoration success. Restoration of a range of grazing sensitive plant species which now either regionally extinct or remain in small isolated population will almost certainly require changes to grazing regimes, reintroduction of fire regimes and species reintroductions to ensure viable populations. Reintroducing faunal species will also require attention to connectivity and habitat availability issues in this context as many are dependent on the existence of large, interconnected territories e.g. Hooded Scaly-foot (Pygopus schraderi).

The Northern Plains Grasslands Protected Area Network: Strategic Operational Plan (SOP) is a landscape-scale strategic operational plan for the conservation management of the Northern Plains Grassland community within Victoria’s Protected Area Network, developed by the Northern Plains Technical Advisory Group in 2011. This Operational Plan now guides TfN and Parks Victoria in the implementation of an adaptive management plan for the landscape. This plan aims to establish and implement a restoration program across the public and private protected areas and is a marked shift from the previous management intent of maintenance of the system.

Fig 2. The area, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Fig 2. The northern plains grasslands, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Strategies for management and restoration. There are two main strategies that are being implemented. The first involves the extension of protected areas through a range of mechanisms; and the second involves active management to restore habitat quality and diversity to the extent possible.

Extent. Expansion of the current approach of reserve acquisition and covenanting that has been undertaken by the range of partners is likely to able to target and establish large areas (20,000+ ha) in the Lower Avoca and Patho Plains landscape. Both these areas are high priorities for Trust for Nature and form significant sections of the Trust for Nature’s Western Riverina Focal Landscape. The Patho Plains is significant as it is an Important Bird Area and a focus of Birdlife Australia to ensure the long term persistence of the Plains-wanderer (Pedionomus torquatus). The Lower Avoca also provides important habitat for the Plains-wanderer (Draft National Recovery Plan) and is one of the main population centres for Hooded Scaly-foot in Victoria.

Diversity. The increase of diversity and quality of these systems requires direct intervention in management as well as the introduction and establishment of the many rare and regionally extinct species from the system.

Plant species: Over the past decade, TfN and others have successfully trialled the reintroduction of a number of threatened and common plant species through hand sowing seed into grasslands. These species include: Hoary Sunray (Leucochrysum molle), Leafless Bluebush (Mairena aphylla), Rohlarch’s Bluebush (Maireana rohlarchii), Bladder Saltbush (Atriplex vesicaria), Plains Everlasting (Chrysocephalum sp. 1), Beauty Buttons (Leptorhynchos tetrachaetus), Small-flower Goodenia (Goodenia pusilliflora), Minnie Daisy (Minuria leptophylla) and a range of Wallaby species (Rytidosperma spp.) and Spear Grasses (Austrostipa spp.).

Animal species: Local habitat variability for a range of fauna has been achieved through the modification of grazing regimes and the introduction of burning regimes at a range of sites. This work aims to maximise niches and thus opportunities for a broad range of species.

Fig 3. Hooded Scaly-foot adult by Geoff BrownCOMP

Fig 3. Hooded Scaly-foot adult, a critically endangered legless lizard that occurs in the Northern Plains Grasslands, preferring habitat much like the Plains-wanderer. Photo: Geoff Brown.

Table 2.  Triggers required for various grazing and other management regimes to maintain appropriate intertussock spaces in Northern Plains Grasslands

Table2

Monitoring. The SOP includes a method for rapid assessment of habitat and functional composition of sites to support decision making and track habitat change over time. This is stratified by soil type as grazing and habitat values and floristic communities vary between soil types within the grassland mosaic. Triggers for action or management bounds have been set based on the structure of inter-tussock spaces on red soils. These have been established using the “Golf ball” method which calculates a golf ball score by randomly dropping 18 golf balls into a 1m x 1m quadrat and then establishing a count based on the visibility of the golf balls (>90% visible = 1, 90%-30% visible = 0.5, <30% visible = 0). For red soil grasslands the aim is to maintain the inter-tussock spacing within a golf ball range of 13-16 using the range of tools identified in Table 2. When a paddock reaches a golf ball score of 16 and it is being grazed, stock are to be removed. When the paddock reaches a score of 13 they are then to be reintroduced, within the bounds of the regime that is to be applied.

Additional to this there has also been collection of data in relation to the functional composition of sites with golf ball quadrats also assessed for the presence of a range of functional groups including Native C4 grasses, Native C3 Grasses, Exotic annual grasses, Exotic Perennial Grasses, Native forbs, Exotic Forbs, Native Shrubs, Moss cover, Other Crytptograms (i.e. Lichen, Algae, Liverworts), Bare Ground and Litter. At all these sites photos are also taken of each quadrat with and without golf balls and a landscape photo is also taken.

The capturing of these data and the region wide approach across both public and private areas will increase our knowledge of how to manage and restore these important sites as well as track progress of management actions and their effectiveness in providing protected areas for a range of threatened species.

Acknowledgements. A wide range of partners and individuals are involved in the protection of the Northern Plains Grassland and the development of the Northern Plains Strategic Operations Plan including Parks Victoria, Department of Environment, Land, Water & Planning (DELWP), La Trobe University, Charles Sturt University, Arthur Rylah Institute for Environmental Research, North Central Catchment Management Authority, Northern Plains Conservation Management Network, Elanus Consulting and Blue Devil Consulting.

Contact: Nathan Wong, Conservation Planning Advisor, Trust for Nature (Level 5, 379 Collins Street, Melbourne VIC 3000, Australia;Tel: +61 (0)3 8631 5888; Freecall: 1800 99 99 33; Mob 0458 965 329;Email: nathanw@tfn.org.au, www.trustfornature.org.au).

 

 

 

Update of landowner and community engagement in Regent Honeyeater Habitat Restoration Project – Lurg Hills, Victoria

Ray Thomas

Key words: community engagement, environmental education, habitat restoration

The Regent Honeyeater Project in the Lurg Hills, near Benalla in Victoria, is a habitat restoration project that emphasises that a key to biodiversity conservation is working well with the people who live in the landscape.  In fact the biodiversity gains in the 21 years of remnant protection, plantings and habitat provision in the Lurg Hills, would not have been possible without the support of landowners (who have given their land, their enthusiasm and time to the project) and the many community groups and individuals who come to help with the plantings.  The latest update on landowner and community engagement quoted from the  March 2016 update is as follows.

Increased social engagement. In the last 6 years we have increased the number of visits to planting days by 50 per cent. There has been a steady growth in the number of new local landholders involved and the total number is now 160 landholders engaged, compared with 115 in 2009. Everyone we come across knows of the project and anyone new to the area hears about it from one of their neighbours. Very few people (you could count them on one hand), say they would rather not be involved. In fact we increasingly get cold calls from new people who have observed what has happened on their neighbour’s place and then phone us to say they want to be involved. It’s a positive indication that the project is part of the spirit of the area. This was further confirmed by the inclusion, of a very detailed Squirrel Glider (Petaurus norfolcensis) mural in a recent street art painting exhibition. The permanent artwork is the size of a house wall, and situated prominently in the heart of the parklands of Benalla.

Much of our work has relied heavily on volunteers, with a total of 10,344 students and 24,121 community volunteers involved over the past 21 years. City folk have fewer opportunities to be in nature, with the bushwalking clubs, university students and scouts in particular, really keen to come and roll up their sleeves.

Typically about 17 to 20 of the local schools, primary and secondary, help us with propagating the seedlings at the start of each year and then planting their own seedlings back out into the field in the winter and spring. And we are increasingly getting interest from metropolitan schools that come to the country for a week-long camp. Some of the schools even have their own permanent camps up here and they want to be involved with our hands on work too. “It’s simply part of our environmental responsibility”, is the way they express it.

Contact: Ray Thomas, Coordinator of the Regent Honeyeater Project Inc (PO Box 124, Benalla, Vic. 3672, Australia; Tel: +61 3 5761 1515. Email: ray@regenthoneater.org.au

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Penrhyn Estuary Habitat Enhancement Plan: Habitat Rehabilitation for Migratory Shorebirds in Botany Bay, NSW

Peggy O’Donnell

Keywords: estuarine, restoration, saltmarsh, seagrass, roosting habitat, feeding habitat

Introduction: The Penrhyn Estuary Habitat Enhancement Plan (PEHEP) is an ambitious rehabilitation project undertaken to compensate for habitat loss due to the expansion of Port Botany. Development in Botany Bay, NSW, has caused substantial biophysical changes since the 1940s. Shorebird habitat has decreased due to airport development and expansion and Foreshore Beach is greatly reduced. Penrhyn Estuary is the only remaining significant shorebird roosting and feeding habitat along the northern shoreline but has legacy pollution. The PEHEP was prepared as part of development approval and implemented from 2012 to 2017.

Figure 1: Penrhyn Estuary 2008, before port expansion.

Figure 1: Penrhyn Estuary 2008, before port expansion.

Figure 2: Penrhyn Estuary 2015, four years after port expansion works.

Figure 2: Penrhyn Estuary 2015, four years after port expansion works.

Broad aims and works: The PEHEP aims to rehabilitate the estuary by expanding roosting and feeding grounds for migratory shorebirds and thereby increase their populations in line with Australia’s international responsibilities for shorebird conservation. Key works included levelling of sand dunes to create saltmarsh habitat and expansion of existing intertidal sand flats by filling deeper parts of the estuary with dune sand. A flushing channel was constructed to ensure adequate tidal exchange and to provide habitat suitable for seagrass beds. Protected seagrass, Strapweed (Posidonia australis) was transplanted prior to works and remaining Eelgrass (Zostera capricorni) and Paddleweed (Halophila ovalis) were protected from damage during construction using silt curtains. Local saltmarsh species planted were optimal for use as roosting habitat and extensive weed removal and maintenance was undertaken. Sound barriers, lighting and fencing around the estuary and port structure were designed to favour shorebirds and deter predators.

Monitoring programs compared baseline and post-rehabilitation conditions to assess rehabilitation efficacy. Surveys were done within the estuary and at appropriate reference locations within a BACI experimental design framework. Indicators included: abundance of key shorebird species, benthic infaunal communities, planted and transplanted saltmarsh, remnant and transplanted seagrasses off Foreshore Beach, and water quality.

Results to date:

Water Quality. Four years after habitat enhancement, physiochemical properties (temperature, pH, dissolved oxygen, salinity, total suspended solids, key nutrients) and a productivity indicator (chlorophyll a) were not significantly different from pre-construction or reference values. The configuration of the flushing channel simulated modelled estuary flushing times No algal blooms have been identified to date, suggesting the absence of eutrophic conditions within the now shallower estuary.

Saltmarsh habitat. After planting propagules the total area of saltmarsh habitat in Penrhyn Estuary exceeds 40,000 m2, a 76% increase post port construction and habitat creation (see Sainty 2016 and Dalby-Ball & Olsen 2016 for details of saltmarsh design and planting methodology). Following the works, saltmarsh species diversity, abundance and condition all improved.

The newly-planted saltmarsh vegetation appeared healthy showing continued growth with variability mainly at the margins of planted beds. The main roosting habitat species Salt Couch (Sporobolus virginicus) increased in all treatments, while Seablight (Suaeda australis) decreased slightly consistent with its removal in strategic locations to maintain plant height favourable for shorebird roosting habitat. The ecological function of planted saltmarsh areas was similar to that at reference locations (including other constructed saltmarsh habitats) and a trend of increasing biodiversity was observed throughout the three post-rehabilitation surveys. Some habitats treatments have not responded as well, including those transplanted prior to enhancement works and areas that were cleared of mangroves and weeds. Overall, the majority of ecological targets set with respect to the saltmarsh vegetation within Penrhyn Estuary were met.

Benthic intertidal habitat. Unvegetated intertidal feeding habitat for migratory shorebirds increased by 307% as a result of filling deeper parts of the estuary with dune sand. To enhance invertebrate abundance and diversity, dune sand was augmented with seagrass wrack and river mud as it was profiled in the estuary. Earthworks were staged such that tidal exchange with Botany Bay was altered and/or restricted but never eliminated during the two year construction period.

Criteria for the success of habitat creation were derived from comparison to target values based on pre-enhancement surveys and reference locations. Physical indicators were median grain size and percentage of fine sediments (% clay and silt fractions). Biological indicators were invertebrate abundance and biomass.

After habitat enhancement targets for invertebrate biomass were exceeded, but were not significantly different to those at reference locations. Invertebrate abundance reached only 61% of the target value and decreases resembled those in reference locations. Median grain size and percentage fines in newly created sand habitats were similar to pre-enhancement levels.

The taxonomic composition of benthic assemblages shifted post enhancement. Polychaete worms were characteristic of the assemblage before enhancement while gastropods and bivalve molluscs drove assemblage patterns after enhancement. Polychaetes declined from 76% of all invertebrates before enhancement to 47% after, while molluscs increased from 16% before to 49% after.

Seagrass habitat. Prior to construction, seagrasses off Foreshore Beach had undergone a significant natural decline. Strapweed patches within the footprint of the new boat ramp were transplanted to southern Botany Bay and are now indistinguishable from local plants. Condition of remaining seagrass patches off Foreshore Beach was monitored as was recolonization in the created flushing channel and lower reaches of the estuary.

Three post–construction monitoring surveys have documented a narrow, large bed of Paddleweed containing small patches of Eelgrass and Strapweed that extends off Foreshore Beach in 2-3 m water depth. Small isolated patches of Eelgrass and Strapweed persist at Foreshore Beach. Post-construction conditions are suitable for their survival and larger seagrass beds may be able to re-establish given normal processes of succession. Although numerous patches of the colonising Paddleweed and Eelgrass have been recorded in the flushing channel and in the inner estuary, typically these have not persisted. Turbidity may be limiting light penetration to the deeper parts of the flushing channel and offshore movement of sediments may be smothering seagrasses in the shallower areas of the flushing channel before they can fully establish.

Shorebird populations. Six key species of shorebirds were selected to indicate the success of the rehabilitation project: Bar-tailed Godwit (Lamosa lapponica), Red-necked Stint (Calidris ruficollis), Double-banded Plover (Charadrius bicinctus), Curlew Sandpiper (Calidris ferruginea), Red Knot (Calidris canutus) and Pacific Golden Plover (Pluvialis fulva). Abundance, diversity, health and habitat usage were monitored for these species and compared to target numbers derived from pre-construction data in 2006, as well as counts at reference sites. The frequency and sources of disturbance and observations on predation were recorded in peak and off-peak seasons.

The population of Pacific Golden Plover appears to be responding positively to the works, with the target exceeded in five consecutive seasons. Mean numbers of Double-banded Plover have increased at Penrhyn Estuary throughout both tidal phases, though is yet to meet its target peak count. Bar-tailed Godwit and Red-necked Stint have declined in this period, and there were no sightings of Red Knot or Curlew Sandpiper in the 2015 peak season surveys.

Disturbances to shorebirds in Penrhyn Estuary have been reduced with the completion of the sound barrier around the port side perimeter and exclusion of the public. Predation was high in the peak 2014 season, emphasising the need to control foxes and cats.

Monitoring reports for the PEHEP are available at:

http://www.sydneyports.com.au/sustainability/penrhyn_estuary_rehabilitation/monitoring_and_reporting2

Lessons learned and future directions:

  • Achievement of the desired profile for the site based on modelling and watering of saltmarsh plants in the initial stages likely set the stage for the success in establishing the large tracts of saltmarsh habitat. The initial removal and subsequent maintenance of a mangrove-free estuary, including a floating trash boom is supporting regular weed removal to improve the chances of long-term sustainability.
  • The relatively poorer response of transplanted saltmarsh areas, and those weeded but otherwise undisturbed suggests that for large habitat creation projects, propagating and planting local saltmarsh species is an efficient, appropriate approach the showed good results in the short term.
  • Earth moving works were staged such that the tidal exchange within the inner estuary was never completely blocked. This is likely to be a factor in the rapid reestablishment of benthic invertebrates, whose pattern of succession and composition differs from those reported for similar projects. Together with the improvement of dune sand by the addition of seagrass wrack and river mud, the fundamentals for a sustainable feeding habitat for shorebirds have been laid.
  • Tidal erosion removed a small portion of saltmarsh habitat along the inner estuary margin which was reshaped and repaired without further habitat damage or disturbance to roosting birds. The lesson: despite careful planning, erosive forces can alter habitats unpredictably as created habitats mature, and timely adaptive management is required to rectify damage and reduce further loss.
  • Shorebird populations and invertebrate abundance in the first two years of post-construction monitoring showed a generally positive correlation and similar trajectories of, suggesting that created intertidal habitat provided sufficient prey items to support increased shorebird populations in the longer term, despite considerable variability and failure of both populations to meet some target indicators. The abundance, biomass and community composition of benthic invertebrates in the most recent sampling (November 2014) fell within the range of variation seen in the five previous sampling events, however overall shorebird abundance fell to a minimum. Shorebird observations for the three months up to March 2015 showed an increasing trend, however targets for all but one species (Pacific Golden Plover) have not been achieved.

Comparisons to data from reference locations suggest that some factors may be operating at a range of spatial scales observable along the east coast of Australia. For all but Bar-tailed Godwit they suggest an overall decrease in key migratory species that is not limited to Penrhyn Estuary. Predation (or displacement due to presence of predators) may reduce the population of some shorebirds at some times, but no observations suggest that habitat quality, including roosting habitat and availability of prey items deter or limit the level of shorebird habitat use in Penrhyn Estuary.

Stakeholders and Funding bodies: Port Authority of NSW (Formerly Sydney Ports Corporation) fund and manage all aspects of the project, beginning with EIS studies and construction through to ongoing maintenance and monitoring. NSW Ports provides funding for ongoing maintenance and monitoring. Shorebird monitoring was done by as subcontract to Cardno (NSW/ACT) by Avifauna Research & Services, Email www.avifaunaresearch.com.au

Contact information: Dr Peggy O’Donnell Practice Lead Ecology, Water & Environment, Cardno (NSW/ACT). Tel: +61 2 9496 7700 Mobile +61 422 858 827. Postal PO Box 19, St Leonards NSW 1590. Email peggy.odonnell@cardno.com.au

WATCH VIDEO: Peggy O’Donnell 2014 pesentation to AABR seminar

Saltmarsh translocation and construction, Penrhyn Estuary, Port Botany, NSW

Mia Dalby-Ball and Andre Olson

From June 2008 to June 2011, ecological restoration work was conducted by Port Authority of NSW in association with the expansion of the port at Port Botany, Sydney, NSW. The purpose was to expand and rehabilitate Penrhyn Estuary.

The saltmarsh works at Penrhyn Estuary involved 2.4 hectares being densely planted with saltmarsh species. In addition to this 3000m2 of saltmarsh was translocated within Penrhyn Estuary. The key driver for the saltmarsh design and plant selection was the requirement for the project to provide habitat for migratory wading birds.

There were many key aspects to the project. Primary among them was the engagement of an expert to undertake a pre-words evaluation and design the wetland construction. It was also important that planning involved representatives from different disciplines including those who would be doing the on-ground work and those monitoring migratory birds. Another key aspect was that approvals and licenses were identified and obtained early.

Saltmarsh construction. Seed collection (from local sources) and plant growing was carried out more than a year before plants were required. (This is because saltmarsh plants are slow to grow, there is a narrow window of time for seed collection and permits are required to collect seed or pieces.)

Implementation works first involved removal of dune weeds (Bitou-Bush, Chrysanthemum monilifera ssp. rotundifolia) and saltmarsh weeds, in particular Spiny Rush (Juncus acutus) of which large plants were hand removed and or cut and painted with herbicide. Germinating seedlings were irrigated with Saltwater. Monthly inspections undertaken with immediate removal of new plants.

This was followed by excavation of land so that it became inundated by monthly high tides. (Monitoring of tidal inundation was carried out to test that levels were appropriate and areas that had water pooling in excess of five days were filled.)

Soil conditioner (organic rich soil) was spread over the sandy substrate and mixed to 100mm, using cultivation equipment. This was followed by planting of over 250,000 saltmarsh plants including of Beaded Glasswort (Sarcocornia quinqueflora) and Salt Couch (Sporobolus virginicus). All saltmarsh plantings were irrigated with fresh water via a sprinkler system.

Fig 1. Translocating Beaded Glasswort via electric boat. (Photo: Dragonfly Environmental)

Fig 1. Translocating Beaded Glasswort via electric boat. (Photo: Dragonfly Environmental)

Translocation of saltmarsh. A 3000m2 area of Beaded Glasswort and Salt Couch was growing on an area that was to be excavated to become mudflats. This area was cut into ~ 20cm x 20cm blocks with 100mm deep soil and lifted by hand (shovels) and put onto wooden sheets (plywood) and transported to the recipient site. Transportation was chiefly by a small boat with electric motor (Fig 1).

The saltmarsh was translocated to the site where the Spiny Rush had been removed. At the recipient site it was planted into the substrate (Fig 2). Spaces between blocks were filled with soil from the donor site. The entire area was irrigated thoroughly with salt water. Irrigation continued for six months while the transplanted material established.

Monitoring. Monitoring existing saltmarsh and proposed saltmarsh creation sites prior to, during and for 2 years post works. Additional monitoring has been conducted for a further 3 years.

Fig 2. Transplanting clumps of Beaded Glasswort and Salt Couch into areas where Spiny Rush had been removed. (Photo: Dragonfly Environmental)

Fig 2. Transplanting clumps of Beaded Glasswort and Salt Couch into areas where Spiny Rush had been removed. (Photo: Dragonfly Environmental)

Fig 3. Sprinkler irrigation during saltmarsh planting. Fresh water irrigation continued for at least 6 months post-planting. (Photo: Dragonfly Environmental)

Fig 3. Sprinkler irrigation during saltmarsh planting. Fresh water irrigation continued for at least 6 months post-planting. (Photo: Dragonfly Environmental)

Lessons learned. At over 230,000 saltmarsh plantings, to our knowledge this is the largest recorded saltmarsh construction project recorded to date. A number of findings have resulted from the project, particularly our trials to arrive at a suitable growing medium for the plantings. We sought a soil that had free drainage good moisture retention properties and contained available nutrients. Fertiliser tablets alone are insufficient in sandy soils. We trialed a range of soil conditioners, with the most successful having high organic content and did not float. Irrigation is required as tidal inundation is not adequate to keep soil moist for seedlings. We found that irrigation was required for at least 6 months

Acknowledgements: Design and pre-works site evaluation was conducted by Geoff Sainty of Sainty and Associates and BioAnalysis.  Implementation and monitoring of saltmarsh during construction and establishment phase (two years monitoring) was carried out by Dragonfly Environmental.  Cardno (NSW/ACT) has been conducting environmental monitoring post establishment phase.

Contact: Mia Dalby-Ball, Ecological Consultants Australia, 30 Palmgrove Road,  Avalon NSW 2107, Australia (Tel: 0488 481 929; Email: ecologicalca@outlook.com) or Andre Olson, Dragonfly Environmental, 1/33 Avalon Parade, Avalon NSW 2107 Australia (andre@dfe.net.au).