Fish to get help one step at a time
Native fish will be able to swim freely along the entire length of the Murray River with "fish ladders" now being installed along the river.
The ladders are gently sloping passages that will allow the fish to migrate upstream past weirs, locks and barrages.
Man-made barriers, first built 150 years ago to help steamships travel along the Murray and for irrigation, have long restricted fish from travelling along the river, including to areas with low fish populations.
Federal Environment Minister Ian Campbell, who was in Mildura yesterday to launch the $25 million project, said the ladders would help the breeding process, boosting fish numbers and genetic diversity.
He said the aim was to give native fish unrestricted access to the entire river - 2225 kilometres from the sea at Goolwa to the Hume dam - by the end of the decade.
"Over the past 200 years, the numbers of native fish populations in the Murray-Darling Basin have fallen dramatically and those that have survived have become fragmented and their movement seriously restricted," Mr Campbell said.
"Experts estimate that current levels are about 10 per cent compared to pre-European settlement."
The initiative is part of a Government plan to increase native fish populations over the next 50 years to 60 per cent of what they were before European settlement.
At least one-third of the 35 native fish species in the Murray-Darling Basin have been listed as vulnerable or endangered because of threats such as habitat degradation, poor water quality and man-made barriers.
A major report into environment flows to the river last year also recommended structural improvements, such as fish ladders, be introduced to restore the river to health.
The leading author of the report, Co-operative Research Centre for Freshwater Ecology chief executive Gary Jones, yesterday said: "Things like weirs, locks and dams are not particularly good for the environment, but what we're trying to do now, through smarter design is make them good for the environment as well as the irrigators."
He said the new ladders would replace some existing ladders that were installed in the river last century, but were inappropriately designed for stronger European fish.
"They're like a staircase almost, with little resting chambers or rooms on each level of the staircase where the fish can rest," Professor Jones said.
"It means it's not as hard for our wimpy Australian fish who don't swim as well as salmon and fish like that, to go up and down."