Developments in Big Scrub Rainforest Restoration: UPDATE of EMR feature

Tony Parkes, Mark Dunphy, Georgina Jones and Shannon Greenfields

[Update of EMR feature article: Parkes, Tony, Mike Delaney, Mark Dunphy, Ralph Woodford, Hank Bower, Sue Bower, Darren Bailey, Rosemary Joseph, John Nagle, Tim Roberts, Stephanie Lymburner, Jen Ford and Tein McDonald (2012) Big Scrub: A cleared landscape in transition back to forest? Ecological Management & Restoration 12:3, 212-223. https://doi.org/10.1111/emr.12008]

Key words: Lowland Subtropical Rainforest, ecological restoration, seed production, landholder action, corridors

Figure 1a. Rainforest regenerators undertake camphor injection, leaving bare trees standing creating light and an opportunity for seed in the soil to naturally regenerate. (Photo © Envite Environment)

Figure 1b Aerial photo showing camphor conversion by injection
(Photo © Big Scrub Regeneration Pty. Ltd.)

Introduction. The Big Scrub, on the NSW north coast, was once the largest tract of Lowland Subtropical Rainforest (LSR) in Australia. It was reduced to less than 1% of its original extent by he end of hte 19th century after clearing for agriculture. Big Scrub Landcare (BSL) is a non-profit organisation dedicated to improving the long-term ecological functionality of what remains of this critically endangered ecosystem –  lowland subtropical rainforest.  Our 2012 EMR feature reported on remnant restoration and revegetation works overseen by BSL to 2012. At that time, 68 remnants were identified as significantly affected from the impacts of environmental degradation including weed invasion and cattle access. These remnants had been undergoing treatments, with 20 substantially recovered and on a ‘maintenance’ regime.  Approximately 900,000 trees had been planted to establish 250 ha of young diverse well-structured rainforest.  A comparatively small area of forest dominated by the highly invasive exotic, Camphor Laurel (Cinnamomum camphora) (Camphor), which  has colonised much of the Big Scrub landscape had been converted to early phase LSR by skilled removal of a range of weeds and facilitating natural regeneration. 

Progress since 2012. Substantial progress in restoring critically endangered lowland subtropical rainforest in the Big Scrub has been achieved over the past seven years in the following areas.

• Assisted regeneration of remnants has continued and become more focused
• Re-establishment of LSR through plantings has expanded
• Camphor conversion has developed in scale and techniques
• Greater security of funding has been achieved
• Community engagement has greatly improved and expanded
• Genome science is being applied to produce seed with optimal genetic diversity for rainforest restoration.

Assisted regeneration of remnants. This work continues to be the major focus of on-ground restoration work. About 2000 regenerator days (9 years Full Time Equivalent) of work has been undertaken in 45 remnants. BSL’s remnant restoration program has become more strategic, with more focus on Very High Conservation Value (VHCV) remnants, particularly those in the NSW National Parks Estate, including the VHCV sites in Nightcap National Park (NP) including Big Scrub Flora Reserve, Minyon Falls and Boomerang Falls; Andrew Johnston’s Scrub NR; Snow’s Gully Nature Reserve (NR); Boatharbour NR; Victoria Park NR and Davis Scrub NR, plus the Booyong Flora Reserve. Rehabilitation work at these sites is prioritised in the major new four-year Conservation Co-funding project funded jointly by BSL and the NSW government’s Saving our Species program. Big Scrub Foundation (BSF) funding has enabled BSL to continue maintenance work in remnants that have reached or are approaching the maintenance stage.

Monitoring outcomes has become more rigorous and has demonstrated ongoing improvements in vegetation structure, with decreasing levels of weed invasion and improvements in native species cover.

BSL’s partner Envite Environment, with some assistance from BSL, is creating an important linkage between Nightcap NP and Goonengerry NP by the restoration of rainforest through the progressive removal of weeds that had dominated the 80 ha Wompoo/Wanganui corridor between these two NPs.

 Re-establishment of rainforest by planting. The area of LSR is being re-established by planting on cleared land has also continued to expand.   In the last 7 years  more than 0.5 million rainforest trees have been planted in the Big Scrub region, contributing to the restoration of another 175 ha of LSR, expanding total area of re-established rainforest by another 13%. While landscape-scale landholder driven work is inevitably opportunistic rather than strategic, the establishment of new patches of LSR enhance valuable stepping-stone corridors across the Big Scrub. Since 2012 the number of regenerators working fulltime in the Big Scrub region has increased by approximately 50%.  Another trend that has strengthened in the last 7 years is that larger plantings are now being carried out by well-resourced landowners. This is accounting for about 40% of the annual plantings. Offsets for residential development account for another 40% of trees planted. The remaining 20% is made up by small landowners, cabinet timber plantations, large-scale landscaping, and other planting of Big Scrub species. This is a significant change from the more dominant grant-based small landowner/Landcare group plantings prior to 2012.

 Camphor conversion. Larger areas of Camphor forest are being converted to rainforest, with project areas increasing substantially from less than a hectare to ten and twenty hectares. BSL estimates that more than 150 ha of Camphor forest are currently under conversion. Some landowners underake camphor injection which leaves bare trees standing, creating light and an opportunity for existing native seedlings and seed in the soil (or seed dropped by perching birds) to naturally regenerate (Fig 1). Others are choosing the more expensive option of physically removing the Camphor trees and carefully leaving the rainforest regrowth (Fig 2).  Improved techniques and landholder capacity building continue to progress and camphor conversion is now a significant component of rainforest restoration.

BSL alone is facilitating the conversion of almost 40 ha of Camphor forest to LSR funded by two 3-year grants from the NSW Environmental Trust, together with contributions from the 19 landholders involved in these projects. The ecological outcomes being achieved are significant and less costly than revegetation via plantings.

Figure 2a. Camphor forest under conversion using heavy machinery leaving rainforest regrowth intact (Photo © Big Scrub Landcare)

Figure 2b. Aerial photo showing camphor conversion by removal
(Photo © Big Scrub Landcare)

Greater security of funding. Australian Government funding for biodiversity conservation is at a very low level. Competition for existing NSW state government funding is increasing. BSL therefore has continued to  develop new strategies for fund raising to ensure continuity of its long-term program for the ecological restoration of critically endangered LSR in the Big Scrub and elsewhere. Ongoing funding of at least $150,000 annually is needed to ensure the great progress made  over the past 20 years in rehabilitating remnants is  maintained and expanded to new areas of large remnants. These funds finance weed control and monitoring; weeds will always be a part of the landscape and an ongoing threat to our rainforest remnants.

Establishment of the Big Scrub Foundation in 2016 was a major development in BSL’s fund raising strategy. The Foundation received a donation of AUD $1M to establish a permanent endowment fund that is professionally invested to generate annual income that helps finance BSL’s remnant care program and its other activities. Generous donors are also enabling the Foundation to help finance the Science Saving Rainforest Program.

Figure 3a. Australian gardening celebrity Costa Gregoriou at a Big Scrub community tree planting (part of the 17th annual Big Scrub Rainforest Day) in 2015 (Photo © Big Scrub Landcare)

Figure 3b. Founder of the Australian Greens political party Bob Brown and Dr. Tony Parkes at the 18th annual Big Scrub Rainforest Day in 2016. (Photo © Big Scrub Landcare)

Community engagement. The  Big Scrub Rainforest Day continues to be BSL’s  major annual community engagement event, with the total number of attendees estimated to have exceeded 12,000 over the past 7 years; the 2016 day alone attracted more than 4000 people (Fig 3). Every second year the event is held at Rocky Creek Dam.  A new multi-event format involving many other organisations has been introduced on alternate years.

BSL’s Rainforest Restoration Manual has been updated in the recently published third edition and continues to inform and educate landowners, planners and practitioners.

BSL in partnership with Rous County Council produced a highly-commended book on the social and ecological values of the Big Scrub that has sold over 1000 copies. BSL’s website has had a major upgrade: its Facebook page is updated weekly; its e-newsletter is published every two months. BSL’s greatly improved use of social media is helping to raise its profile and contribute to generating donations from the community, local businesses and philanthropic organisations to fund its growing community education and engagement work and other activities.

Science saving rainforests program. BSL, the Royal Botanic Gardens Sydney, the BSF and their partners have commenced an internationally innovative program to apply the latest DNA sequencing and genome science to establish plantations to produce seed of key species with optimal genetic diversity for the ecological restoration of critically endangered lowland subtropical rainforest. This program will for the first time address the threat posed by fragmentation and isolation resulting from the extreme clearing of Australia’s LSR, which is estimated to have resulted in the destruction of 94% of this richly biodiverse Gondwana-descended rainforest.

Many  key  LSR species are trapped in small populations in  isolated remnants  that  lack the genetic diversity needed to adapt and survive in the long term, particularly faced with climate change Necessary  genetic diversity is also lacking in many key species in the 500 ha of planted and regrowth rainforest. The first stage of the program, already underway, involves collecting leaf samples from approximately 200 individual old growth trees in 35 remnant populations across the ranges of 19 key structural species of the ‘original’ forest. DNA will be extracted from the leaf samples of each species and sequenced. The  latest genome science will be applied to select the 20 individual trees of each species that will be cloned to provide planting stock with optimal genetic diversity for the establishment of a living seed bank in the form of a plantation that will produce seed  for use in restoration plantings. As the individual trees in the restoration plantings reproduce, seed with appropriate genetic diversity and fitness will be distributed across the landscape. The project focuses on key structural species and thus helping the survival of Australia’s critically endangered Lowland Subtropical Rainforest in the long term.

Lessons learned and current and future directions. A key lesson learned some five years ago was that BSL had grown to the point where volunteers could no longer manage the organisation effectively. BSL took a major step forward in 2015 by engaging a part-time Manager, contributing to BSL’s continuing success by expanding the scope, scale and effectiveness of its community engagement activities and improving its day to day management.

The principal lesson learned from BSL’s on-ground restoration program is to focus on rehabilitation of remnants and not to take on large planting projects, but rather support numerous partnered community tree planting events. Large grant-funded multi-site tree planting projects are too difficult to manage and to ensure landholders carry out the necessary maintenance in the medium to long term.

Acknowledgements.  BSL acknowledges our institutional Partners and receipt of funding from the NSW government’s Saving our Species program, NSW Environmental Trust and Big Scrub Foundation.

Contact:  Shannon Greenfields, Manager, Big Scrub Landcare (PO Box 106,  Bangalow NSW 2479 Australia; . Tel: +61 422 204 294; Email: info@bigscrubrainforest.org.au Web: www.bigscrubrainforest.org.au)

Donaghy’s Corridor – Restoring tropical forest connectivity

Key words: tropical forest restoration, habitat connectivity, small mammal recolonisation, ecological processes, community partnerships.

Introduction. Closed forest species are considered especially susceptible to the effects of forest fragmentation and habitat isolation. The Wet Tropics of north Queensland contains many forest fragments between 1ha and 500ha, mostly surrounded by dairy and beef pastures, and crops such as maize, sugar cane and bananas. Larger blocks are often internally fragmented by roads and powerlines. The Lake Barrine section of Crater Lakes National Park is a 498ha fragment that is 1.2km distant from the 80,000ha Wooroonooran N.P, and ecologically isolated since the 1940s with detectable effects on genetic diversity of rainforest mammals.

In 1995 the Qld Parks and Wildlife Service, along with landholders and the local ecological restoration group TREAT Inc., began riparian forest restoration along Toohey Creek to re-connect the Barrine fragment to Wooroonooran and to document colonisation by small mammals and native plants typically associated with rain forest environments (Fig 1).

Fig 1. Donahy’s Corridor, Atherton Tablelands, linking Crater Lakes NP and Wooroonooran NP, Qld (Photo TREAT).

Connectivity Works. Prior to works commencement, small mammal communities (e.g. Rattus spp. and Melomys spp.) along and adjacent to Toohey Creek were sampled, along with a full vegetation survey, to determine base-line community composition and structure. Permanent stock exclusion fencing was erected and off-stream stock watering points established.

A 100m wide corridor of vegetation was established over a four year period using local provenances of 104 native species comprising around 25% pioneer species, 10% Ficus spp., and the remainder from selected primary and secondary species. In total, 20,000 trees, shrubs and vines were planted along the creek, and a three-row shelterbelt was planted adjacent to the corridor to reduce edge effects. Species were selected on a trait basis, including suitability as food plants for targeted local fauna e.g. Cassowary (Casuarius casuarius johnsonii).

Ecological furniture (e.g., rocks, logs) was placed prior to planting. On completion, the 16ha Donaghy’s Corridor Nature Refuge was declared over the area, recognising the Donaghy family’s significant land donation and the corridor’s protection by legislation. A three year monitoring program, conducted quarterly, commenced on completion of planting.

Fig. 2. Developing rainforest in Donahys Corridor (Photo Campbell Clarke)

Monitoring. Flora monitoring was conducted along transects bisecting the four annual plantings (1995/96/97/98), and small mammal colonisation in 11, 20m x 20m plots located in the plantings, adjacent open paddocks, and in forests at either end. Small mammal sampling included mark-recapture and DNA studies, to determine colonisation and movement patterns and genetic effects.

Results. Three years after establishment, over 4000 native plants were recorded – representing 119 species from 48 families. This included 35 species naturally dispersed from the adjacent forest (Figs 2 and 3). Small mammal sampling showed 16 long-distance movements by Rattus species and the appearance of an FI hybrid Bush Rat (Rattus fuscipes) in the central section of the corridor in the third year of the study. The rainforest rodent Fawn-footed Melomys (Melomys cervinipes) had established territories in the second year of the study. A study of wood-boring beetles (Coleoptera)in ecological furniture showed 18 morpho-species in a three year period. Many other orders/families were also recorded.

Water quality in Toohey Creek was not studied but has continued to increase since the replacement exotic grasses with woody vegetation, and the exclusion of cattle from accessing the stream. There is increased shade available for stock and less pressure on the limited number of existing paddock shade trees.

 Fig. 3. Indicators of rainforest structure (species and layering) and functions (habitat providion, nutrient cycling, recruitment) are now highly evident. (Photo Campbell Clarke).

What we learned.

• Plant colonisation was rapid, dominated by fleshy-fruited species (10-30mm diameter), of which a proportion are long-lived climax species
• Plant colonisation was initially highest in the interior, close to the creek margin, but has become more even over time
• Vegetation structural complexity and life form diversity have continued to increase since establishment
• Small mammal communities changed in response to habitat structure, grassland species dominate until weeds are shaded out when they are replaced by closed forest species
• Many long distance mammal movements occurred that were only detected by genetic analysis
• Monitoring showed small mammals used the new habitat to traverse from end to end until resources were worth defending: at that time long distance movements declined and re-capture of residents increased
• Partnerships between government, research bodies, community groups, and landholders are essential if practical solutions to fragmentation are to be developed and applied

Acknowledgements: Trees for the Evelyn and Atherton Tableland acknowledges and appreciates the support of all the volunteers involved in this project, staff from the Qld Parks and Wildlife Service-Restoration Services, , James Cook University, University of Qld, Griffith University and UCLA Berkely. In particular we would like to acknowledge the Donaghy family.

Contact: TREAT Inc. PO Box 1119, Atherton. 4883 QLD Australia. http://www.treat.net.au/

SEE ALSO:

Global Restoration Network Top 25 report: http://www.treat.net.au/projects/index.html#donaghy

Watch the video on RegenTV – presented by Nigel Tucker

 

 

 

 

 

 

 

 

Update on Regent Honeyeater Habitat Restoration Project (7 years on) – Lurg Hills, Victoria

Ray Thomas

Key words: Agricultural landscape, faunal recovery, community participation, seed production area

Twenty-one years of plantings in the Lurg Hills, Victoria, have seen a consolidation of the work described in the 2009 EMR feature Regent Honeyeater Habitat Restoration Project.  The priorities of the Project are to protect and restore remnants and enlarge them by add-on plantings. Together, this work has protected relatively healthy remnants by fencing; restored depleted remnants by planting or direct seeding; and revegetated open areas that had been cleared for agriculture. Other restoration activities include mistletoe removal, environmental weeding, environmental thinning; feral animal control, kangaroo reduction, nest box placement, and systematic monitoring of a range of threatened and declining woodland birds and hollow-dependent mammals.

Updated outputs since 2009. A further 540 ha of private land has now been planted (150 additional sites since 2009). This means the total area treated is now 1600ha on over 550 sites. The oldest plantings are now 19 years old and 10m high (compare to 12 years old and 6m high in 2009) (Fig 1).

The total number of seedlings planted is now approx. 620,000 seedlings compared with 385,000 in 2009. Some 280km fencing has been established compared with 190 km in 2009. Mistletoe now treated on scores of heavily infested sites

Fig. 1. Ecosystem attributes developing in 19-year-old planting at Dogleg Lane (Foster’s). Note pasture grass weeds are gone, replaced by leaf litter, logs, understorey seedling recruitment, open soil areas.

Improvements in genetics and climate readiness. As reported in 2009, seed collection is carried out with regard for maximising the genetic spread of each species, to prevent inbreeding and more positively allow for evolution of the progeny as climate changes. This has meant collecting seed in neighbouring areas on similar geological terrain but deliberately widening the genetic base of our revegetation work. We are also attempting to create as broad bio-links as possible so that they are functional habitat in their own right (not just transit passages). This may allow wildlife to shift to moister areas as the country dries out. With a species richness of 35–40 plant species for each planting site, we also enable natural selection to shift the plant species dominance up or down slope as future soil moisture dictates.

2016 Update: In recent years we have engaged with geneticists from CSIRO Plant Division in Canberra, to improve the genetic health of our plantings. Many of our local plants that we assumed to be genetically healthy, have not recruited in our planting sites. For example, Common Everlasting (Chrysocephalum apiculatum) produces very little if any fertile seed each year because it is sterile to itself or its own progeny (Fig 2 video). In fragmented agricultural landscapes, it seems that many of our remnant plants have already become inbred, and it is seriously affecting fertility, form and vigor. The inbreeding level has affected fertility in this particular case, but we have several other cases where form and vigor are seriously affected as well.

Fig 2. Andie Guerin explaining the importance of collecting seed from larger populations. (Video)

Seed production area. We have now set up a seed production area (seed orchard) for about 30 local species that are ‘in trouble’, to ensure that the plants have sufficient genetic diversity to reproduce effectively and potentially adapt, should they need to as a result of a shifting climate. This will allow these populations to become self-sustaining. Each species is represented in the seed production area by propagules collected from typically10-15 different sites (up to 20kms and sometimes 50kms distant) and as many parents as we can find in each population.

We aim for at least 400 seedlings of each species, to ensure the genetic base is broad enough to have the potential for evolution in situ. The planting ratios are biased towards more from the bigger populations (that should have the best diversity), but deliberately include all the smaller populations to capture any unique genes they may have. We plant each population in separate parallel rows in the seed orchard to maximise the cross pollination and production of genetically diverse seed for future planting projects. We have noticed that the health of some of these varieties is greatly improving as a result of increasing the genetic diversity. On one site we direct-sowed Hoary Sunray, sourced from a large population, and it has since spread down the site very quickly (Fig 3).

Fig 3. Small sub-shrubs and herbaceous species are generally not planted in stage 1 of a project, as the weed levels are often too high for such small plants to succeed. These plants are only introduced in stage 2, when the weeds have diminished up to a decade later. This approach has been very successful with direct seeding and planting some of our rarer forbs.

Recruitment of Eucalypts now evident. Nearly 20 years on from the first plantings, we can report that quite a number of sites have eucalypts old enough to be flowering and seeding, and some of them are now recruiting. We are delighted that our early efforts to broaden the planting genetics are demonstrating success with such natural processes (Figs 1 and 3). Ironbark recruitment from our plantings commenced in 2014 and Red Box commenced in 2015.

Recruitment can also be seriously affected by herbivore problems, particularly rabbits. In recent years we have been undertaking careful assessments of rabbit load on a potential planting site and have gained some advantage by deploying an excavator with a ripper attached to the excavator arm. The excavator allows us to rip a warren right next to a tree trunk (in a radial direction), or work close to fence without damaging either. We’re finding this is providing a very good result. On one site we suspected there were a few warrens but it turned out to be just short of 30 warrens within 100 m of the site – each with 30-40 rabbit holes. After ripping all of those, we ended up with activity in only 2 of the warrens, which were then easily retreated.

We have had such good results with the rabbits on some sites that we are trialing planting without tree guards – it’s much more efficient on time, labour, and costs. And adjacent to bush areas, where kangaroos and wallabies are a significant threat to plantings, this process has an extra advantage. It seems that macropods learn that there is something tasty in the guards, so a guard actually attracts their attention. Our initial trials are producing some good results and given us confidence to expand our efforts with thorough rabbit control.

Faunal updates. An important objective of the project is to reinstate habitat on the more fertile soils favoured for agriculture, to create richer food resources for nectarivorous and hollow-dependent fauna including the Regent Honeyeater (Anthochaera phrygia). In 2009 the Regent Honeyeater was nationally Endangered and was thought to be reduced to around 1500 individuals. By 2015, it was thought to be reduced to 500 individuals, and so has been reclassified as Critically Endangered.

Regent Honeyeaters have turned up in recent years in gully areas where the soils are deeper, the moisture and nectar production is better, and there is a bit more density to provide cover against the effects of aggressive honeyeaters like the Noisy Miner (Manorina melanocephala). The Regent Honeyeaters have been able to remain on such sites for around for a week or more, but have not bred on the sites to date. But breeding has occurred about 15kms away on the eastern edge of our project area. Radio-tracking showed that these breeding birds were some of the captive-bred birds released at Chiltern 100km further NE, and that the birds came towards Lurg after the Chiltern Ironbarks had finished flowering. We consider it to be just a matter of time before the Regent Honeyeaters will find the many habitat sites we’ve planted on higher productivity soils in the Lurg area.

Formal monitoring of Grey-crowned Babbler (Pomatostomus temporalis temporalis) for the past last 13 years has documented a rapid rise (due to some wetter years) from 60 birds in 19 family groups to approx. 220 birds in 21 family groups. There is also exciting evidence that the endangered Brush-tailed Phascogale (Phascogale tapoatafa) is returning to the Lurg district. The distinctive shredded Stringybark nests are now found in scores of our next boxes (up to 10km from the site of our first records of 2 dead specimens in the south of our project area in the mid 1990s). This dramatic population spread is presumably a direct result of our carefully located corridor plantings that have bridged the habitat gaps all across the district.

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

READ MORE

• Global Restoration Network Top 25 Report: http://regenthoneyeater.org.au/grn.php
• Landcare: http://www.landcareonline.com.au/?page_id=8350
• EMR full feature article: Regent Honeyeater Habitat Restoration Project, Lurg Hills, Victoria

 

 

Management of genetic resources within the Murray-Darling Basin

Key words: Murray- Darling Basin, fish, genetic diversity, genetic resources, Native Fish Strategy.

The Native Fish Strategy aims to rebuild all fish stocks within the Murray-Darling Basin (MDB) to 60 percent of pre-European settlement levels within 50 years. To achieve this target, management responses would be assisted by an understanding of the underlying genetic diversity of species. Many species have genetically distinct populations. For example, Murray Cod (Macculochella peelii) are known to have little genetic difference throughout most of the southern range of the MDB, however, several populations (Lachlan, Macquarie and Gwydir catchments) were found to be genetically distinct.

Maintaining genetic diversity is critical to species and ecosystem resilience, particularly in the face of changing environmental conditions. Despite the explicit recognition within legislation that genetic diversity is a key component of biodiversity, until now there remains no consistent or practical guidelines for the management of these resources.

Project objectives and methods: The objectives of this project were to create a resource able to be used to guide the management of genetic diversity within the Basin.

Specific objectives:

• Review current genetic management practices across the MDB;
• Review the current knowledge base for genetic structure within native fish species in the MDB and identify knowledge gaps;
• Hold an international workshop to define the level of genetic management required to maintain distinct evolutionary significance of native fishes within the MDB;
• Suggest a consistent approach to the management of genetic resources for native fish in the MDB.

A survey of fisheries agencies was conducted to identify current genetic management protocols for hatchery management, restocking, translocations, conservation captive breeding programs, fish rescues and interventions and the monitoring of threatened species. Protocols for the collection, preservation and storage of genetic material (e.g. fin clips, biopsy material, scales, bones, cryopreserved sperm, etc.) were also identified.

Previous and contemporary genetic research of MDB species was reviewed to highlight and map inferred genetic boundaries within the Basin. All available published and unpublished molecular data were compiled to assist in determining genetic structuring, ecologically sustainable units and management units. Strengths, weaknesses and implications of these data were considered, knowledge gaps highlighted and methods for addressing these gaps were discussed.

A workshop was held to determine what level of genetic management is appropriate for fish in the MDB and bring together experts to present the latest thinking on defining conservation units, to help inform development of a framework for prioritising and managing evolutionary distinction. Review findings and workshop outputs were then used to inform development of guidelines for management of genetic diversity in Australian native fish within the MDB which includes:

• a review of current genetic issues and management practices across the MDB;
• a review of the genetic structuring for native fish and crustacean species in the MDB including knowledge gaps;
• guidelines and recommendations for genetic management within the MDB;
• a genetic management template for fish stocking; and,
• recommendations from the Management of Genetic Resources for Fish and Crustaceans in the Murray-Darling Basin workshop.

Figure 1. Studies have indicated there may be up to five discrete populations of Golden Perch (Macquaria ambigua) in the Basin (Photo courtesy of Jamin Forbes)

Figure 2. Studies have shown there to be five distinct genetic populations of Murray Cod in the Basin (Photo courtesy of Jamin Forbes)

Findings and recommendations: Available data on genetic subdivision for 65 fish and crustacean species across the MDB were reviewed and discussed in the context of management for these species. This review highlighted significant genetic differences between populations of native fish and crustaceans within the Basin. These genetically different populations potentially contain unique evolutionary heritage that will require specific approaches to manage.

A number of recommendations were provided from this project:

• Populations that are defined as distinct genetic management units should be treated as unique populations with limited transfer of individuals between units (Figs 1 and 2).
• Information provided through this project should be used to develop a unified approach to the management of genetic diversity within the MDB.
• The substantial knowledge gaps for species with insufficient genetic data (outlined in species profiles) should be addressed to allow the identification of genetic management units for the MDB.
• Adequate stocking and hatchery genetic protocols should be adhered to for all breeding programs within the MDB.

Stakeholders and Funding bodies: This project was funded through the Murray-Darling Basin Authority’s Native Fish Strategy.

Contacts: Dr Andy Moore, Department of Agriculture Fisheries and Forestry. Tel: + 61 2 6272 3090, Email: anthony.moore@daff.gov.au.

Assessing the impacts of native fish stocking on fish within the Murray-Darling Basin (MDB)

Key words: fish stocking, impacts, native fish, Murray-Darling Basin

Fish stocking (i.e. hatchery production of fish to a size or stage so that they can be released into an area) has been practiced worldwide for centuries, but it is only recently that the environmental and ecological risks have been recognized. Stocking has been undertaken largely to enhance recreational angling but also to aid conservation of a species. Regardless of the objectives, appropriate and effective management of stocking activities is required because a number of risks exist, which are not always well understood.

Broad aim and methods: This project reviewed the impacts of native fish stocking on fish within the Murray-Darling Basin (MDB), and also provided a summary of stocking activities within the MDB. Potential impacts on abundance and behaviour, genetics, disease and ecosystem level effects were considered.

A review of literature was undertaken to consider the impacts of native fish stocking on fish within the MDB. Research papers were evaluated using the following criteria: a) whether the research was relevant to native fish stocking; b) whether the design was confounded; and, c) whether the analysis and interpretation of data were correct and the conclusions valid. Studies that did not meet these criteria but provided useful information to generate hypotheses were also considered.

The review focused on four potential impacts of stocking: abundance and behavioural responses; genetic implications; spread of disease; and ecosystem level effects.

Figure 1. There is a need to ensure that potential risks associated with stocking are acknowledged and managed. (Photo courtesy of Michael Hutchison)

Findings: Changes to abundance and behaviour of fish from stocking were reported to arise mainly through competition between stocked and wild fish. These effects can be either direct (for food and habitat) or indirect (habitat alteration, behavioural changes, expansion of species range and displacement of wild stocks). Generally, there has been a lack of research on abundance and behavioural responses to fish stocking on native Australian species.

Genetic impacts of hatcheries and hatchery fish on wild populations were noted to have received a lot of attention, but the literature is mainly theoretical in nature. Genetic effects can be direct (e.g. hybridisation) and indirect (e.g. reduction in population size caused by predation, competition and diseases). Artificial breeding of fish also alters the genetics of captive bred populations. At the time of this project, very little was known about the genetic structure of native fish populations in the MDB.

Impacts of introducing diseases, parasites and exotic organisms unintentionally when stocking fish were noted to have received little attention. The accidental introduction of a disease with the stocking of native species is most likely to have a negative impact on wild populations. Several examples of the spread of pathogens through stocking exist for the MDB.

Ecosystem alteration from stocking fishes is extremely difficult to demonstrate, and has mostly been attributed to introduced species rather than native species.

Figure 2: Fish stocking can assist fish conservation or enhancing recreational fisheries, but can also impact on wild populations and ecosystems if not managed correctly. (Photo courtesy of Lee Baumgartner)

Lessons learned and future directions: The review concluded that targeted research on MDB species is needed for all potential impacts and highlighted a need for sound baseline data and monitoring programs. Many species of native fish in the MDB are stocked in some way and the potential impacts outlined in this review should be considered when designing or reviewing stocking programs to maximise desired effects (i.e. boost numbers of stocked species) and minimise negative effects on resident native fish species (Figs 1 and 2). The study identified potential benefits in undertaking a risk assessment of potential impacts prior to stocking and conducting experimental evaluation and monitoring of any stocking program.  Only with such an approach will the success of stocking programs be evaluated and the risks mitigated.

Stakeholders and Funding bodies: This project was funded through the Murray-Darling Basin Authority’s Native Fish Strategy, and conducted by Bronwyn M. Gillanders, Travis S. Elsdon and Andrew R. Munro University of Adelaide and Woods Hole Oceanographic Institution.

Contact: Professor Bronwyn Gillanders, University of Adelaide, bronwyn.gillanders@adelaide.edu.au or +61 8 830 36235.

Seagrass meadow restoration trial using transplants – Cockburn Sound, Western Australia

Jennifer Verduin and Elizabeth Sinclair

Keywords: marine restoration, seagrass, Posidonia australis, transplant, genetic diversity, microsatellite DNA, provenance

Cockburn Sound is a natural embayment approximately 16 km long and 7 km wide, to the west of the southern end of the Perth metropolitan area. Its seagrass meadows have been reduced in area by 77% since 1967, largely due to the effects of eutrophication, industrial development and sand mining. To answer a range of questions relevant to seagrass restoration, we (i) carried out a transplant trial, (ii) monitored the impact and recovery of the donor site, and (iii) retrospectively assessed genetic diversity in the transplant site.

Methods. (i) The transplant trial was conducted between 2004 and 2008 in an area totalling 3.2 hectares of bare sand at 2.2–4.0 m depth on Southern Flats, Cockburn Sound. Donor material was sourced from a naturally occurring seagrass meadow on Parmelia Bank, north of Cockburn Sound, approximately 16 km away from the transplant site. Sprigs (15–20 cm length) of a dominant local seagrass, Posidonia australis Hook.f., were harvested from donor material and each sprig tied to a purpose-designed degradable wire staples (30 cm in length) and planted and secured into a bare sandy area at 50 cm shoot spacing by SCUBA divers (Figure 1). Sprig survival was periodically monitored in 10 m x 10 m representative sub-plots (15–20 plots per hectare).

(ii) For the meadow recovery study, several plug (a clump of seagrass excavated) extraction configurations were examined in P. australis meadows to monitor shoot growth into plug scars, with metal rings placed into the resulting bare area to monitor shoot growth into it at 3, 10, 13 and 24 months. Rings of 8.3 cm diameter were placed into adjacent undisturbed meadows to act as reference plots. (iii) Shoot material was collected from established plants for microsatellite DNA genotyping from the donor site in 2004, and from the 2007/2008 plantings in the restoration site in January 2012. Genetic sampling from the restoration site was done from mature shoots only, to ensure we were sampling original donor material. DNA was extracted from shoot meristem and genotyped using seven polymorphic microsatellite DNA markers (Sinclair et al. 2009).

Figure 1. Transplants in situ, prior to the pegs being covering with sediment (Photo Jennifer Verduin)

Results. (i) The transplants have grown well to fill in gaps and become a healthy, self-sustaining meadow, with first flowering in July 2010, three years after initial transplant in 2007. There has also been considerable natural recruitment in the area through regrowth from matte and new seedlings (Figure 2). (ii) No significant differences in shoot growth between extraction configurations were observed in the donor meadow, and there was an increase in shoot numbers over two years. Based on the number of growing shoots, the predicted recovery time of a meadow is estimated at three years. (iii) Genetic diversity was very high in the restored meadow (clonal diversity R = 0.96), nearly identical to the donor meadow.

Figure 2. Aerial view of the restoration site (within yellow markers), with natural recruitment occurring from vegetative regrowth and new seedling recruits (Photo Jennifer Verduin, 2010).

Important considerations for long-term success and monitoring. While several important questions have arisen from this trial, it demonstrated that (i) the transplants achieved a high level of establishment within a few years; (ii) the high genetic diversity in the donor site was captured and retained in the restored meadow; and (iii) surrounding sandy substrate is being colonised by P. australis through regrowth from the matte and natural recruitment from seeds dispersed within and/or from other meadows, (the latter potentially helping to ensure the long-term viability of restored seagrass meadows.)

Partners and Investors: This project was carried out as part of the Seagrass Research and Rehabilitation Program through Oceanica Consulting Pty Ltd, with Industry Partners Cockburn Cement, Department of Commerce (formerly Department of Industry and Resources), WA, Department of Environment and Conservation WA, The University of Western Australia, and the Botanic Gardens and Parks Authority, WA.

Contact: Jennifer Verduin, School of Environmental Science, Murdoch University, Murdoch, WA 6150 Australia Email: J.Verduin@murdoch.edu.au; Elizabeth Sinclair, School of Plant Biology, University of Western Australia, Crawley, WA 6907 Australia Email: elizabeth.sinclair@uwa.edu.au. If you are interested in becoming involved with seagrass rehabilitation through student projects please contact us.