This section provides guidance on how to undertake on-ground management actions to rehabilitate ecosystem health for native fishes. It is important to involve the community in on-ground management interventions such as re-snagging and riparian rehabilitation, and to celebrate milestone achievements throughout the life of the demonstration reach.
The Whole of Life Plan (see Planning Pillar) will have identified the management interventions to be undertaken (e.g. riparian rehabilitation, alien fish management, fish passage restoration), and the sequence in which they are to roll out. Ideally, all management interventions would be undertaken simultaneously throughout the demonstration reach, however, this is generally not possible, so interventions must be planned over a number of years in relation to the resources and funds available.
The first steps are to:
- Undertake an assessment of the current condition of the reach and the existing threats to ecosystem health.
- Document the necessary steps (actions) to mitigate each threat.
- Engage the broad community and major stakeholders to identify shared goals for the reach.
- Prioritise actions on both biological and community needs (this builds a shared ownership of the project).
- Consult with appropriate experts to design how and where the interventions will be implemented, what the resource and cost requirements are likely to be, and consider undertaking a cost benefit analysis.
- Connect with jurisdictional agencies to determine the legislative and administrative constraints.
A works program can then be drawn up, scheduling the management actions over a period of time (e.g. 3 years) with the funds and resources required. When drawing up the works program it is important to be aware of all the issues that may arise, for example, accessing qualified contractors, ongoing maintenance costs, meeting legislative requirements etc. The program has to be realistic given the expected availability of funds and resources, but the interventions must be of sufficient scale that they are likely to have a measurable impact on native fishes. It is also vital that the works program and the biological monitoring and evaluation program are planned together and properly coordinated.
There are number of management interventions that have been used to rehabilitate degraded rivers throughout Australia and a number of these, together with some new innovative approaches have been trailed at existing demonstration reaches. Broad guidelines and examples of the more common interventions are provided.
- A works program is required to schedule management interventions and outline resourcing and funding requirements. This works program and the Monitoring and Evaluation Plan must be coordinated.
- The re-introduction of large woody debris (snags) should be based on the natural load of the particular river and native to the riparian zone but, ideally, not sourced from that location.
- Options such as the re-establishment of aquatic macrophytes, rock rubble etc. can be considered for providing instream habitat for small bodied fish.
- When rehabilitating the riparian zone, priority should be given to protecting healthy riparian vegetation by preventing clearing, stock and vehicle access. Rehabilitation of degraded riparian vegetation may be achieved by encouraging natural regeneration (e.g fencing) or through rehabilitation activities like direct seeding or planting of tubestock.
- Many water quality problems may be mitigated by other interventions such as riparian rehabilitation. Identifying water quality issues and their sources requires event based monitoring.
- Rehabilitation of flow regimes through the provision of environmental releases requires coordination with jurisdictional and Commonwealth agencies.
- Re-establishing fish passage involves identifying the movement requirements of fish to determine the location of potential barriers and the mitigation options available.
- Screening of irrigation offtakes may prevent large numbers of native fishes from being lost to the demonstration reach through water diversions. Demonstration reaches are well placed to trial different options for offtake screening.
- An integrated pest management approach must be taken when dealing with alien fish including the development of a separate management plan.
- Fish stocking should only be undertaken if there are no alternatives, fingerlings must be obtained from a hatchery where there is a recognised quality assurance program, and all hatchery released fingerlings should be tagged.
ACT Government 2010. Upper Murrumbidgee Demonstration Reach Implementation Plan. Department of Territory and Municipal Services, Canberra.
Boys, C.A., Lyon, J., Zampatti, B., Norris, A., Butcher, a., Robinson, W. and Jackson, P. 2014. Demonstration Reaches. Looking back whilst moving forward with river rehabilitation under the Native Fish Strategy. Ecological Management and Restoration, 15 (Supplement 1), 67-74.
Rutherfurd, I.D., Jerie, K. and Marsh, N. 2000. A Rehabilitation Manual for Australian Streams, Volumes 1 and 2. Land and Water resources Research and Development Corporation Cooperative research Centre for Catchment Hydrology, Melbourne.