THE MURRAY COD DOMAIN THE MURRAY-DARLING BASIN Last updated 27/03/2007

    The Murray Cod's domain is the mighty Murray-Darling basin that is spread across 4 states of Australia and covers much of south-eastern Australia. This huge river and natural drainage system encompasses parts of Queensland, New South Wales, Victoria, South Australia and the entire Australian Capital Territory (A.C.T.) and covers more than one million square km and is 5,300 river km long.

    The Murray Cod is the dominant predator and is only found in this river system. Compared to many countries around the world, this river system maintains a relatively low number of fish species and a very short history of human interference other than indigenous communities using this river system and it's fish species as a food source only. However, during this brief time of human involvement (200yrs-brief in historic terms), the Murray-Darling basin has suffered greatly due to many dams, weirs and regulators  that have been constructed. Irrigation has become the main use of this river system and has brought about many problems and still to this day there has not been any viable solutions applied to assist it's diminishing flora and fauna. There has been some minor projects that is slowing the degradation of the Murray-Darling basin, ie. Native fish stocking programs, re-snagging programs, removal of non-indigenous tree's, plants and re-vegetation of farmlands on the river system, but all these projects are far from solving the problems of salinity or returning the natural flows these waterways had before European settlement.

    The realm of the Murray Cod survives on seasonal river flows, spring floods, naturally occurring water temperatures, snags from fallen timber and access to upstream and flooded shallow spawning grounds. With many of these requirements being altered or not available it has forced the Murray Cod and the entire Murray-Darling basin's ecosystem to adapt to the new environments that we have left it. Although we do not expect to loose all life from this river system but it would be rather naive to say that we will not lose some of it's co-habitants in the future as there will never be a return of the natural river system in the pending future. At best we may be able to control some of the water releases to best suit some of the naturally occurring seasonal flows and to re-design  water impoundments to release the upper levels (warmer water) of its water system so there is no great inrush of cold water into the waterways in the warmer months of the year. Salinity can be vastly removed by re-vegetation of areas that were once covered with open woodland, although it's not the solution but has been shown in the past to make a great difference. All in all we have left the Murray Cod's domain in a very poor state and it will take years and many millions of dollars to at least stop further degradation. Then multiply this again by many time more and we might even start to bring this mighty river system into a healthy state although sadly it will never be the same as the years before European settlement.