Rivers and estuaries are important components of the ecosystem providing habitat for many fish, aquatic invertebrates, birds, amphibians and reptiles. Estuaries are places of transition from freshwater to seawater and are subject to marine and freshwater influences. The health or condition of rivers,
estuaries and associated vegetation communities can be negatively impacted by increasing salinity, sedimentation, pollution, removal and destruction of instream habitat, and altered flow regimes. These threatening processes can impact on the fauna directly, through toxic effects, or indirectly, including
by the loss of suitable breeding, sheltering and feeding sites and isolation of populations due to loss of water connectivity between floodplains and river systems. Restoration of aquatic habitats aims to return these systems back to a natural state and minimise threats. By measuring the condition of
aquatic systems we can establish the severity of detrimental impacts and threats and develop strategies for restoration efforts.
Fishways and fish movements - why keeping fish habitat connected is important
Fish need to be able to move freely among habitats to successfully complete all stages of their life-history. Fish move upstream and downstream (often up to many hundreds of kilometres), as well as into and out of connected wetlands and floodplains. Fish undertake these movements for various reasons
including spawning, feeding and dispersal.
Connectivity of waterways is a key characteristic of a healthy aquatic ecosystem as it enables fish movements to be unrestricted. Aquatic habitats and waterways have been modified by the construction of dams, weirs and culverts to provide hydropower, irrigation and navigation. This provides important
community benefits, but it has also changed how rivers flow, altered water quality, and reduced river connectivity. These changes have led to reductions in population sizes and distribution of many fish species. To help alleviate some of these impacts there are a number of solutions that can improve
ARI has a long history in creating ways for fish to move past barriers, including the design of structures known as fishways. Fishways are complex to design and install, and vary from multiple rows of rocks, to series of connected concrete chambers. Designs are based on the ability of fish to swim and
manoeuvre against a current, which varies depending on size and species. Numerous attributes contribute to the design of a fishway including water velocity, turbulence and light levels, and they can vary in success due to factors such as the size of fish using them. For example, fishways are often effective
for large individuals, but it is more challenging for fish less than 40 mm in length to pass upstream. ARI works closely with Catchment Management Authorities, water authorities and the community to reconnect rivers across Victoria with the aim of helping to improve native fish populations.
For more information contact: firstname.lastname@example.org or email@example.com
The report below provides a framework for developing site-specific guidelines for fishways
Assessing the benefits of environmental water in Victoria
'Environmental water' is water that is released into rivers, floodplains, wetlands and estuaries to improve waterway health, and to protect environmental values. The development and implementation of environmental watering programs in Victoria occurs as a collaborative process between state and commonwealth
government agencies, land managers and water authorities. Understanding how to maximise the benefits of environmental watering requires the support of ecological data, and underpins the decision-making processes of these programs. In view of this, the Victorian Government established the Victorian Environmental
Flows Monitoring and Assessment Program (VEFMAP) in 2005, to monitor and evaluate the ecological benefit of environmental water use in Victoria. VEFMAP is currently being implemented in eight major regulated rivers where there has been an allocation of environmental water.
DELWP have worked with ARI and the University of Melbourne to review and analyse data collected by VEFMAP and other complementary research, and to explore the relationship between environmental water releases and ecological responses of native fish and vegetation.
VEFMAP has provided valuable baseline information on fish communities to support managers. Some other key findings include:
of the threatened status of 11 native fish species, and the dominance of non-native fish species such as Carp
in abundance and distribution of particular native and non-native fish species have been identified. These include recovery of Murray Rainbowfish in some northern rivers, range expansions of several native coastal fish species, and some spawning responses of Carp to flooding events
case studies of Australian Grayling, Golden Perch and Silver Perch have identified ecological responses to environmental flows which can inform planning
encroachment of terrestrial vegetation into river channels in response to prolonged periods of inundation
abundance of native riparian vegetation in response to short periods of inundation
Important findings such as these help to inform decision-making for future environmental watering.
For more information about key program and research findings contact firstname.lastname@example.org (fish) or email@example.com (vegetation)
For more information about VEFMAP contact: firstname.lastname@example.org
ARI has developed four fact sheets that summarise some of the key results:
Finbox: a Demonstration Reach river restoration toolbox
A Demonstration Reach is a proven river restoration model that has been tested over the last 10 years throughout the Murray-Darling Basin, including two locations in Victoria. Its success in rehabilitating river reaches for native fish is largely due to the emphasis on the four components, or pillars,
of community involvement, planning, on ground interventions and monitoring and evaluation. These pillars are all considered essential for a Demonstration Reach to be effective. The model also embraces the concept of adaptive management so that interventions can be modified as required depending on monitoring
To share this model, so that it can be used more widely, a toolbox has been developed by numerous contributors and ARI, to provide a valuable resource for all those interested in river restoration. Finbox outlines how to effectively establish and implement each pillar, and includes case studies and further reading. Finbox explains the importance of genuine, committed and long-term engagement with the community; the
necessity for integrated and strategic planning and implementation of works; and the fundamental need for effective monitoring and evaluation.
Demonstration Reaches have significant potential to be implemented across Australia. People identify with fish and Demonstration Reaches represent an effective method of harnessing community interest and participation in river rehabilitation where results are measurable and can be celebrated. Finbox
provides the tools to do this. Demonstration Reaches were developed under the Murray-Darling Basin Authority's Native Fish Strategy, and included ARI involvement in its Victorian program.
For more information contact: email@example.com
River restoration - Victorian Demonstration Reach Program
Native fish populations within the Murray-Darling Basin have declined dramatically since European settlement, due to habitat degradation, decreasing water quality, impediments to fish passage, lack of environmental flows and the presence of introduced pest species. In an attempt to increase fish populations
and improve fish habitat, the Murray-Darling Basin Authority implemented a rehabilitation program targeted at specific stretches of river, referred to as a 'Demonstration Reach'. Another aim of the Victorian Demonstration Reach Program was to involve the community in rehabilitating waterways and to show
how this can improve river health. Two locations, in north-east Victoria, were included in the program: the Ovens River and Hollands Creek.
ARI conducted annual monitoring of the fish community from 2008 to 2014, starting prior to rehabilitation works, which were implemented by local Catchment Management Authorities. Rehabilitation activities included the removal of weeds such as Willows from river banks, fencing off rivers to prevent stock
damage, and re-vegetating riparian zones. Snags (large woody debris such as logs) were also placed into the water to enhance fish habitat. The extensive community engagement component included regular events to remove pest fish species, such as Carp, and enjoyed strong support from the public with high
levels of participation.
Fish monitoring has shown that where the river rehabilitation occurred, there have been spectacular increases in the numbers of key fish species including the threatened Murray Cod, Trout Cod and Macquarie Perch. The proportion of native fish compared to introduced species has also increased. Following
the demonstrated success of these Demonstration Reaches, there are plans to apply the process on a larger scale within the Murray-Darling Basin and in other river systems to contribute to improving the health of Victorian waterways.
For more information contact: firstname.lastname@example.org
Videos produced during this project provide more information on pest fish removal, the release of Macquarie Perch, and the Ovens and Hollands Creek Demonstration Reaches:
Growth response of native fish to flows in the mid-Murray River
River regulation, whereby flows are controlled for use such as irrigation supply, have had detrimental effects on rivers throughout the world. Environmental water delivery, where water is released into a river aimed at restoring natural flows, is increasingly being used to improve river health. Fish
populations are often used to track the success of environmental water delivery, however there is limited knowledge on how a river's flow regime is linked to the life-history of fish species. If we can better identify how fish respond to particular flow conditions, particularly the timing, volume and
variability, it will increase our ability to effectively use environmental water to benefit fish and river health. The Murray-Darling Basin Authority (MDBA) funded ARI to examine links between flow regimes and the growth of long-lived native fish, given the link between fish growth (which indicates food
availability) and river health.
We calculated annual growth rates of several fish species, including the nationally endangered Trout Cod Maccullochella macquariensisover a 23 year period, by examining bands on otoliths (inner ear bone of fish). Data were from the highly regulated Murray River, and the unregulated Ovens River. Events affecting river flow that occurred during the study period included major drought, floods and
environmental water delivery. Higher growth rates of Trout Cod in both rivers was related to increased water volume and flow variability, particularly in spring, summer and autumn. This same pattern occurred in Murray Cod Maccullochella peelii and Golden Perch Macquaria
ambigua in the Murray River, indicating that fish in regulated rivers will respond to flow variables in a similar way to those in unregulated systems.
Modelling of this data also predicts Trout Cod growth in the Murray River would be much higher under unregulated flows. This supports the view that increased river regulation, which reduces important natural variations in flows, has been a major factor in the decline of native fish populations in the
Murray-Darling Basin. In addition, high fish growth in the Murray River appeared to coincide with environmental water delivery. This provides support and guidance for the effective use of environmental water to enhance fish populations, which can be applied in similar systems.
The following fact sheet provides more information on the project aims and activities:
The Murray River resnagging experiment - demonstrating the benefits of large scale river restoration
Historical widespread removal of structural woody habitat (snags) in the Murray River is recognised as a significant factor in the decline of native fish populations. To alleviate this decline, the Murray-Darling Basin Authority's 'The Living Murray' program
undertook a large-scale habitat restoration project in 2006 to restore 4,450 snags in the Murray River between Lake Hume and Lake Mulwala. To date, this project is the largest restoration (and subsequent monitoring) project of its kind within Australia.
ARI scientists conducted a seven-year monitoring program (2007-2013) to assess the effectiveness of the program at increasing fish populations. We studied the population responses of four iconic large-bodied native species: Murray Cod Maccullochella peelii, Trout Cod Maccullochella macquariensis, Golden Perch Macquaria ambigua ambigua, and Silver Perch Bidyanus bidyanus. Our monitoring strategy was designed to estimate annual changes in fish population sizes within areas that had been resnagged, as
well as areas where no restoration was undertaken. An extensive mark-recapture program was carried out at up to 424 sites per year using boat electrofishing techniques. We also obtained information on fish age, length and weight relationships, and fish movement, the latter of which was determined by
tracking around 1400 radio-tagged individuals. Information from angler logbooks was also utilised.
Specific findings include a three-fold increase in the Murray Cod population within the resnagged area, with our movement data indicating that part of this increase was due to fish immigrating into the restored stretch of the river. This study has shown that this large-scale river restoration effort
has enhanced native fish populations, which will have multiple ecological and recreational fishing benefits within the Murray River. This study also included activities that increased community awareness and actively engaged multiple stakeholders in building knowledge around the importance of healthy
habitat for native fish and river health.
For more information contact: email@example.com or firstname.lastname@example.org
The following fact sheet on the project, and article on electrofishing techniques used during this study is available:
The Native Fish Strategy - bringing native fish back 2003-2013
In 2003 the Murray-Darling Basin Authority launched the Native Fish Strategy (NFS). The NFS recognised that native fish populations across the Murray-Darling Basin had declined to just 10% of levels at European settlement. The strategy aimed to restore native
fish back to 60% of those pre-settlement levels, through partnerships and collaboration (jurisdictions, policy and management, research and communities) across the Murray-Darling Basin. ARI was a key partner in the strategy, through a suite of research projects, working with other partners in implementing
on ground actions, and hosting a full time NFS Coordinator for Victoria. The NFS used a multi-pronged approach of research (identifying the threats and priority actions), partnerships and action.
ARI undertook NFS research to develop new population modelling approaches for Murray cod; non-lethal methods to discriminate between wild and stocked fish; a more integrated approach to river rehabilitation through two Demonstration Reach projects; a scientifically-based methodology for resnagging; and development of the award-winning Williams' Carp cage, which separates adult carp moving through fishways while automatically releasing native fish. ARI work under the NFS also provided
us with a significantly improved understanding of the ecology of some threatened species (including Murray Cod, Macquarie perch, Murray Hardyhead, Barred Galaxias and Freshwater catfish) better security of species (such as Barred Galaxias and Macquarie perch) affected by emergency events such as fire
and an improved understanding of the management of environmental flows for fish (including, for example, in the Barmah Forest).
The NFS Coordinator at ARI played a key role in building partnerships for these projects; sharing news about NFS activities and research outcomes with a wide range of stakeholders; and building understanding and advocacy amongst other agencies, landholders, recreational fishers, schools, Landcare groups
and Indigenous communities.
For more information contact: email@example.com
For an overview of the NFS including research and publications see the Finterest website
Lower Snowy River monitoring and assessment program
The East Gippsland Catchment Management Authority (EGCMA) has been working with a range of stakeholders to improve the health of the Snowy River, including fencing and revegetation of riparian zones. Through the implementation of the Gippsland Region Sustainable Water Strategy, there is also potential to better use environmental water releases to benefit the river. In recent
years management efforts have concentrated on the lower reaches of the Snowy River including its estuary, with significant community and management interest, and indications that trial water releases had environmental benefits.
In 2013, ARI commenced four integrated programs to help inform and improve management of the lower Snowy River and associated wetlands. This will involve investigating environmental flows, native fish, wetland biota and habitat connectivity. Flow regimes will be studied to determine which regime is
optimal, how this can be delivered and what the environmental outcomes of water releases are. Flows influence riverine biota and processes such as fish spawning and are therefore an important component of river health. Fish surveys will focus on the high priority threatened species Australian Grayling Prototroctes maraena and the regionally iconic Australian Bass Macquaria novemaculeata to assess their population status and recruitment. There will be an inventory of wetland values, threats and condition, including surveys of amphibians, reptiles, fish, waterbirds and water quality.
These programs encompass mapping and modelling and will develop survey protocols which will provide a valuable resource for managers. ARI is working closely with the EGCMA, Parks Victoria and engineers to complete these programs over the next several years.
For more information contact: firstname.lastname@example.org
Helping fishers improve fish habitat in Victorian coastal and urban waterways
Healthy waterways that contain a diverse and abundant supply of fish habitat are essential for productive and sustainable recreational fisheries. Fish habitat (i.e. where fish live, including the water, plants, logs and rocks) provides fish with everything they need to complete their lifecycle: shelter,
food and areas to spawn. The connectivity between habitat components and the condition of streamside vegetation also contributes to fish habitat health and fish food. By improving fish habitat, we can help make more fish, while creating better, more sustainable fishing opportunities.
Victorian recreational fishers are increasingly becoming advocates for rehabilitating waterways due to an increased awareness of how improving fish habitat benefits our fisheries. ARI is aiming to harness that interest by facilitating the involvement of fishers in improving fish habitat in the estuaries
along Victoria's coast, and urban waterways within Melbourne and Geelong. ARI will be coordinating engagement events, and fisher participation in particular activities carried out by coastal catchment management authorities and Melbourne Water. Habitat rehabilitation activities may include installing
instream woody habitat and revegetating river banks.
There are over 700,000 recreational fishers in Victoria, many of whom fish in rivers, lakes and estuaries. Unfortunately, many Victorian waterways have undergone dramatic reductions in health, largely due to modifications of flow regimes and habitat degradation. This has reduced fish populations and
adversely affected recreational fishing opportunities. Victorian recreational fishers are continually becoming more aware of the benefits of improving fish habitat. Over the past decade, fishers have invested more than $3 million of Victorian recreational fishing licence trust funds in fish habitat rehabilitation
projects, including the Victorian Fishers for Fish Habitat Program.
In 2012, ARI, VRFish and Fisheries Victoria become partners to the Australia-wide Fish Habitat Network. The Fish Habitat Network focusses on 'making more fish naturally' by improving habitat that fish need to survive and reproduce. The
Victorian Fish Habitat Network partners successfully obtained funds to establish the Victorian Fishers for Fish Habitat Program. This program enables Victorian recreational fishers to more actively contribute and benefit from the Fish Habitat Network.
The program is being coordinated by ARI and aims to:
raise awareness of the Fish Habitat Network and the critical role of habitat condition on recreational fishing outcomes among recreational fishers
facilitate collaboration between recreational fishing organisations and Fisheries Victoria, Catchment Management Authorities and other resource managers to apply and secure funds for fish habitat related projects
encourage fisher involvement in on-ground actions to improve fish habitat
Instream woody habitat (IWH), commonly referred to as 'snags', consists of trees, branches and logs that fall or are washed into rivers and streams. IWH has a range of functions essential for maintaining the health of a waterway, and in turn supports recreational fisheries and other social and cultural
values. In the past, IWH has been removed from many Victorian rivers for boating purposes, property protection and to reduce flooding. Research has since shown that the removal of IWH has minimal impact on flood mitigation, and that such works impair river stability and degrade river health. The removal
of IWH has also been identified as a major factor in the decline of many freshwater fish populations. River restoration programs often involve the re-introduction of IWH, however more information on current levels of IWH are needed to help focus efforts.
ARI has been involved in a collaborative project to investigate past and current IWH densities in Victorian rivers. Field assessments of IWH densities were undertaken in 'pristine' rivers using GPS and underwater sonar technology. Predictive modelling of this data was then used to estimate natural IWH
densities in rivers across Victoria. Current densities of IWH were calculated using field assessments and high resolution aerial photographs. A comparison of the predicted natural and current IWH densities enabled researchers to assess the overall condition of IWH densities throughout Victorian rivers.Close
to 27,700 km of rivers were mapped for IWH densities. On average, current IWH densities were 41% below estimates of natural IWH levels. Nearly 17,000 km (62%) of rivers were classified as having IWH densities severely (80% below natural levels) or highly depleted (60% below natural levels).
Catchment managers can use this broad-scale assessment of IWH to identify areas in most need of rehabilitation activities. ARI is continuing to investigate what IWH levels are needed to maximise benefits for particular fish. This project was a collaboration with other DELWP divisions, Fisheries Victoria,
Catchment Management Authorities, the University of Melbourne and Melbourne Water, with funding from the Victorian Investment Framework. Establishing the Fish Habitat Network in Victoria and encouraging communities to participate in river restoration programs have also been key parts of this project.
For more information contact: email@example.com
Victoria's coastal aquatic systems encompass all rivers, estuaries and wetlands south of the Great Dividing Range. These environments play a vital role in the social, economic and environmental health of the state. To improve the management of native fish, large decapod crustaceans and large bivalve
molluscs in these systems, a suite of resources have recently been released. These include a published management guide, an on-line decision-support tool, and educational materials. These resources have been designed to assist local natural resource managers with various aspects of fish management, and
to increase awareness and understanding of fish ecology, habitat needs and impacts of threatening processes. The development of these products was funded by the National Heritage Trust.
The 'Guide to the Management of Native Fish: Victorian Coastal Rivers and Wetlands' provides information on fish biology and habitat requirements for native fish that occur in the coastal catchments of Glenelg Hopkins, Corangamite, Port Phillip, Western Port, West Gippsland and East Gippsland. It outlines
how various threats to river health may impact on particular species and will link closely with the existing implementation of regional River Health Strategies. Broad recommendations are provided on how to set priorities and make informed decisions about native fish management.
FAST (Fish Assessment Support Tool) is a web-based decision-support tool to help managers to more effectively consider fish requirements within existing and future river protection and rehabilitation programs. The educational materials include 15 stickers featuring 10 significant freshwater and estuarine
fish species, and five important habitats. There are also six fact sheets outlining key habitat features and issues important to coastal native fish. Three posters highlight over 50 important freshwater, estuarine fish and crayfish species and include distributional maps, information on altitudinal zones,
habitats, recreational and cultural values, threatened status, spawning calendars, and up and downstream movement of larvae, juveniles and adults. The crayfish poster also includes some key features to distinguish terrestrial, aquatic and semi-aquatic crays.
For more information and copies of these products contact: firstname.lastname@example.org
The following fact sheets provide information on five important coastal habitats:
Shorebirds and benthos at the Western Treatment Plant
The Western Treatment Plant (WTP) is managed by Melbourne Water to treat over half of Melbourne's sewage. The area is also an important habitat for shorebirds, with some species migrating each year to Australia from Arctic breeding grounds up to 12,000 km away. These extraordinary migrations are fuelled
by large amounts of food; birds need to build up enormous fat reserves to migrate successfully. Shorebirds are also known as "waders" because they forage by wading in mud and shallow water. They are attracted to the WTP because it provides rich foraging habitat, with very high densities of burrowing
invertebrates ("benthos") found in tidal flats along the foreshore. It is likely that decades of effluent discharges from the WTP have enriched this habitat. Some shorebirds also feed in the shallower freshwater ponds of the WTP. Melbourne Water has commissioned ARI to undertake research to help conserve
the shorebirds and their habitat.
Protecting or enhancing shorebird habitats is challenging, as the tidal flats and freshwater wetlands in which they live are complex, dynamic habitats. An ongoing study is investigating the relationship between the abundance of shorebirds and their food source at the WTP. Repeated shorebird surveys
were coupled with surveys of abundance of their benthic prey. These studies showed that shorebird abundance in the WTP is strongly correlated with abundance of benthos. Benthos abundance was found to fluctuate locally over time, and shorebirds moved their feeding grounds in response.
Many questions still need to be answered. For example, why does abundance of benthos vary so much over time? What prey densities are needed to make a foraging site suitable for shorebirds? With a more complete understanding of the relationships between shorebirds and their prey, we will be better placed
to ensure that their habitats are managed appropriately.
For more information contact: email@example.com