There was a time you could throw a line into the Murrumbidgee River and be almost guaranteed of catching a native fish.
These days, the effects of river regulation, in combination with other pressures that impact native fish, mean that anglers have to be a little more patient.
But what if that wasn’t the case? What if there was something we could do to increase native fish numbers and improve the health of the river at the same time?
Well . . . there is.
Work is underway to restore the habitat of native fish to provide adequate food, shelter, spawning cues and connectivity across the Murrumbidgee floodplain. Water managers, fish experts and scientists are working to maximise the benefits of water managed specifically for environmental outcomes, including native fish.
And that work is paying dividends.
In the past few months, a population of Golden perch has been detected at wetlands near Hay during monitoring of a watering event managed by the NSW Office of Environment and Heritage. The finding provided evidence of the important role environmental water plays in creating ideal conditions for native fish to breed and grow in a variety of riverine and wetland habitats, and eventually repopulate the river.
OEH Water Management Officer James Dyer said monitoring was an important part of any watering event.
“In this case, it gives us confidence that we are on the right track in providing pulsed flows that encourage spawning, healthy habitat that can feed the growing fish, and flows that allow these fish to return to the river from their wetland feeding grounds,” Mr Dyer said.
At sites where water is being managed for the first time, scientific monitoring provides a baseline of information about the species present.
“Based on this information, we can develop management plans to protect and improve fish populations and conduct further monitoring to ensure these plans are achieving their objectives,” he said.
. . . a healthy river system must be able to provide for the lifetime of the fish – food year-round, shelter, and connectivity at key times to allow the fish to move in and out of the river to complete its lifecycle
“Managing water to a particular site generally provides a range of outcomes. In the early stages, water supports habitat – healthy plants that provide food and shelter. As the wetland grows stronger and more robust, it supports a greater diversity and population of plants and animals, including insects and crustaceans. These in turn become a food source for higher order predators, including fish.
“Importantly, a healthy river system must be able to provide for the lifetime of the fish – food year-round, shelter, and connectivity at key times to allow the fish to move in and out of the river to complete its lifecycle,” he said.
Depending on the site, scientific research may be carried out by a university, a Commonwealth funded program, another state government agency such as DPI Fisheries, or a private contractor.
The end result is increased efficiency in the use of available water, optimum outcomes for a range of species, including fish, and a healthier, more productive river system with flow-on benefits for riverine communities.
“Research and monitoring is ongoing,” Mr Dyer said.
“While environmental water plays a significant role in supporting our iconic fish species, native fish still face significant barriers to movement which isolates populations and makes them more vulnerable to drought.
“It also prevents movement of adults to spawning sites capable of supporting the young fish as they move and mature.
“Using the best available scientific knowledge, we are taking important steps to restore the health of rivers and wetlands in the Murrumbidgee valley.
“In doing so, we are helping to ensure a robust and sustainable native fish population which has added benefits for anyone who likes to cast a line,” he said.