Rosalie Auricht, Chief Executive Officer, Renmark Irrigation Trust, Murray Pioneer

The states in the Murray-Darling Basin have been arguing, seemingly forever, about how to look after and share the rivers.

Even the thinkers behind Australia’s federation in 1900 had to concede in our first Constitution that “The Commonwealth shall not, by any law or regulation of trade or commerce, abridge the right of a state or of the residents therein to the reasonable use of the waters of rivers for conservation or irrigation”.

Yet the States and the Commonwealth still continue the debate on who regulates and controls our river, and “the reasonable use of the waters”, in the Murray-Darling Basin.

Yet the Murray-Darling Basin communities can agree that we want a healthy river. At the MDBA River Reflections conference in Albury, the audience was asked to explore ‘what does a healthy river mean to you?’

Members of the Basin Communities Committee were asked to captain tables to facilitate the discussion. Some tables said healthy communities (economically and socially), some said water security, some said healthy floodplains, some said a sustainable natural ecosystem, some said thriving towns and irrigated agriculture. Many visual concepts came forward.

I quickly found the majority of people sitting at my table were fish people (researchers, professors, conservationists and fishery experts). There is something about fish people that seems to cut through to the core. They said it is simple, we’ll have a healthy river when there are “no carp, native fish are increasing in abundance, and no dead fish (referring to the Lower Darling mass native fish kills) “.

This says it all.

The University of Adelaide has been monitoring conditions at the Lower Lakes since 2007.

In March 2022, 179 carp were counted at 19 sites. A year later, 38,111 were collected from 21 sites. Native fish numbers were significantly lower, with some species not found at all.

People participating in the annual SA Carp Frenzy, at Lake Bonney, would fail to be surprised by that. Researchers from Victoria’s Arthur Rylah Institute, monitoring the condition of native fish and crayfish in the Barmah-Millewa forest in 2022-23, produced similar results. Using drift net sampling, the researchers found “nine silver perch eggs, seven golden perch eggs and 3139 carp larvae”.

Experts from Charles Sturt University are also raising a red flag on the increasing density levels of carp to the detriment of our native aquatic species.

Some of us are lucky enough to remember when the waters of our river and lagoons ran clear. As a young child in the Riverland, I watched a fish being slowly reeled in by my uncle. I was mesmerised as the fish swam among the native grasses on the river bed, clearly visible in the dappled sunshine, closer and closer to my yummy dinner. Now that was a healthy river. The fish people in Albury are definitely onto something.

But then the carp came, muddying the waters, and now making up nearly all the biomass in the Murray-Darling Basin. Sorry, States and Commonwealth, it is the carp that have control of our river.

Farmers, communities and fish people in the Murray-Darling Basin have long been calling for the carp to be controlled. We agree, we have a common vision. Controlling the carp is a key step that must be taken to attain a healthy river.

Water quality and habitat will be improved and native fish, crayfish and yabbies will be given the desperately needed uplift to thrive.

Doing nothing is no longer an option – we cannot have the carp stay in control of our river.

Rosalie Auricht is a member of the Basin Communities Committee and CEO of Remark Irrigation Trust. This is her view and not an official representation of either the Committee or the Trust. 

This article appeared in the  Murray Pioneer,  11 September 2024.