They wouldn’t look out of place alongside Nemo on a tropical reef. Like Nemo, they have historically been hard to find, but that is all changing.

The stunning Murray Darling rainbowfish were once widespread across the Basin, including in the Loddon River. But the introduction of redfin and carp, as well as the impacts of river regulation, changed all that.

“They are still listed as vulnerable, but our water for the environment program is helping them make a comeback, in a big way,” North Central Catchment Management Authority (CMA) Environmental Water Manager Louissa Rogers said.

“We have done a lot of work in the past decade, especially since the end of the Millennium Drought to rebuild rivers like the Loddon and restore the habitat and conditions native fish love.

"We have put the right amount of water through the region at the right time which has created a productive environment for a lot of fish, frogs and other animals.

“Monitoring is showing it is working, with a significant increase in Murray Darling rainbowfish in a number of the region’s rivers, including the Loddon. In fact, these fish are booming.”

The monitoring was undertaken by the Arthur Rylah Institute under the Victorian Environmental Flows Monitoring and Assessment Program.

Murray Darling rainbowfish are a small-bodied fish, which can make them extra vulnerable during the hotter months.

“In summer, flows down sections of the Loddon River can stop, and pools are created,” Ms Rogers said.

“That means water quality can suffer and there are fewer areas for smaller fish to hide.

“That’s one of the reasons it’s important to put flows down the river at this time of year. It helps connect the pools, improve water quality and gives aquatic vegetation on the banks a much-needed drink.”

From 19 February, about 100 megalitres of water a day for three days will flow down the Loddon, and about 40ML a day for three days down Serpentine Creek.

“When you think that less than 20 per cent of Victoria’s water is allocated for the environment, and almost 60 per cent for irrigation, flows such as this one are really important,” Ms Rogers said.

“Everyone benefits from a healthy river, and river regulation has resulted in an artificial drought in some sections of our important waterways.

“Restoring native fish populations and building resilience in all our rivers, to prepare for whatever climate change throws at us, is something the community values strongly.”

The flows are part of the Victorian Government’s $222 million investment over the next four years to improve the health of waterways and catchments, and are authorised by the Victorian Environmental Water Holder in line with its Seasonal Watering Plan 2017-18.

The VEWH Seasonal Watering Plan 2017-18 is available for download from www.vewh.vic.gov.au, with regular watering updates posted here.