Understanding how and where fish move can help us manage flows to better support healthy fish populations.
In 2021-22, scientists tracked the movement of 300 golden perch in the lower Darling / Baaka.
The monitoring project was funded by the Commonwealth Environmental Water Holder, managed by the NSW Department of Climate Change, Energy, Environment and Water, and undertaken by staff from the NSW Department of Primary Industries - Fisheries and Charles Sturt University, with project support from the Arthur Rylah Institute and NSW National Parks and Wildlife Service.
Watch the video to see the journey some of these fish took.
Video transcript
The Menindee Lakes are a productive nursery habitat for golden perch.
Dispersal of juvenile golden perch from the Lakes can support populations across the Murray-Darling Basin.
In 2021-22, juvenile golden perch were fitted with tracking tags and released into the lower Darling-Baaka River.
The visualisation you are about to see shows the journey some of these fish took.
River flows had a strong influence on the direction and speed the fish moved, with some fish making the journey all the way to the Murray River.
This information is being used to help guide future releases of water from the Menindee Lakes. A series of tracking stations monitored the movements of tagged golden perch over a period of 6 months.
This first visualisation shows the movements of golden perch in and around the release location between weir 32 and Menindee main weir as a series of moving yellow dots, with each dot representing a different fish.
Corresponding river flows are represented by the graph in the bottom left image, and as river flows increased, we saw heightened activity of fish including numerous movements up to main weir as the fish got to know their new environment.
We also start to see some downstream movements past weir 32 towards Pooncarie, as well as some exploration of Talywalka Creek to the East.
As river flows begin to drop you'll see the first of the tagged fish that makes it to the Murray River highlighted in blue start to make their move downstream.
Next we shift our focus further downstream to Pooncarie where you can see golden perch rapidly moving downstream during moderate river flows, including a mix of both yellow colours (which are fish that remained in the lower Darling Baaka) and blue colours which are fish that eventually made it to the Murray River.
We then pan back to a bird's eye view of the upstream reaches, where golden perch are moving in both upstream and downstream directions exploring their habitats.
Our next series of views show golden perch that have rapidly moved downstream, with those in blue making the almost 500 km journey downstream to the junction with the Murray River at Wentworth.
The last view highlights the journey of one tagged golden perch as it traverses the entire distance of the lower Darling-Baaka, enters the Murray River and rapidly travels downstream where it was last detected near lock 7.
Understanding how and where fish move can help us manage flows to better support healthy fish populations.
