The Edward-Wakool system is a system of multiple rivers and creeks and wetlands intersected by a network of irrigation channels. Listed as an endangered system because of its high biodiversity including threatened and endangered fishes, frogs, mammals, and riparian plants, it has been targeted for longer-term monitoring by the Australian Government.
In the Edward-Wakool system, environmental water is delivered as pulsed flows that remain within the river channels (i.e not overbank flows), so the focus of the assessment is on fish, in-stream ecosystem health and food webs.
In 2012/13 monitoring of responses to environmental watering is being undertaken in a single integrated, multi-disciplinary project involving a number of agencies with complimentary expertise. Collectively the team is monitoring water chemistry ( e.g. carbon, nutrients), algae, phytoplankton (from which estimates of river metabolism can be made), zooplankton, frogs, fish spawning, recruitment and diversity as well as fish movement and habitat assessment
The project's experimental design ensures that a robust assessment of the outcomes of the environmental flows can be undertaken. In the Edward-Wakool system there are multiple rivers of similar size geographically close to each other. As all the rivers can be regulated, some are receiving environmental water, others are not which means control rivers (subjected to usual river regulation management) can be compared with rivers receiving environmental water.
The first report from this study is at http://www.environment.gov.au/resource/monitoring-ecosystem-responses-commonwealth-environmental-water-delivered-edward-wakoollThe final report will be available late 2013.
As part of this project NSW Department of Primary Industries have studied the movements of fish in relation to environmental water delivery using acoustic telemetry methods. A linear array of 48 acoustic receivers was deployed in the Edward Wakool river system. The array incorporates the Wakool River from Gee Gee Bridge upstream to the Edward River offtake and along the length of the Yallakool Creek.
Acoustic tags were inserted in Murray cod (Maccullochella peelii), golden perch (Macquaria ambigua), silver perch (Bidyanus bidyanus) and alien common carp (Cyprinus carpio). The acoustic receivers record time, date and identity of acoustic tagged fish swimming within detection range of the receiver units. The movement of individual tagged fish can be visualised in the following videos that show time series movement of fish in relation to flow. Discharge (ML/D) for the Wakool River and Yallakool Creek is included on the left hand side of the video.
ILWS: A/Prof Robyn Watts (leader), Dr Nicole McCasker, Dr Keller Kopf, Dr Julia Howitt, Dr Susanne Watkins, Dr Skye Wassens, Tim Kaminskas and James Abell
NSW DPI: Dr Lee Baumgartner, Ian Wooden and Chris Smith and Rohan Rehwinkel
Murray CMA: Dr John Conallin, Josh Campbell and Dr Patricia Bowen
Monash University: A/Prof Mike Grace
NSW Office of Environment and Heritage: Sasha Healey and Emma Wilson
Photo from left: Chris Smith, Jim Abell,
Robyn Watts and Tim Kaminskas