The Sea to Lake Hume: Restoring fish passage in the Murray River
Barrett J (Ed) (2008) The Sea to Lake Hume: Restoring fish passage in the Murray River. MDBC Publication No. 32/08. Murray-Darling Basin Commission, Canberra, Australia. 121pp.
Protection of biodiversity and ecosystem processes is a priority for natural resource management in Australia. The construction of dams & weirs in Australian rivers has led to a dramatic decline in native fish populations and aquatic biodiversity generally by reducing opportunities for fish to complete important spawning and re-colonising migrations. In 2001, the Murray-Darling Basin Commission (MDBC) initiated a program to improve fish passage to over 2000 km of the Murray River, from the sea to Hume Dam by constructing 14 new fishways.
A monitoring and assessment program was established to determine if the reinstatement of passage was providing benefits to fish communities in the Murray-Darling Basin. The first fishway (a vertical-slot design) was completed at Lock 8 on the Murray River in 2003. Since then, nine further fishways have been constructed and the research team has performed biological assessments to determine overall improvements to fish populations in the Murray River.
Field assessments using electrofishing surveys, fishway trapping and the tagging and tracking of several fish species have produced data that clearly demonstrate that the 10 new fishways (to October 2007) are setting a new worldwide standard for riverine restoration. Whilst many overseas fishways are designed to pass only a few large-bodied and economically important fish species, the Murray River fishways are unique in their design objective of restoring passage for the majority of the migratory fish community. The fishways are allowing large numbers of fish (e.g., >50,000 over a 40 day period) from many species (13 recorded so far) and covering a wide size-range (31 mm to 1040 mm long) to travel much longer distances within this stretch of the Murray River.
Through collaboration with stakeholders, river management agencies and the wider community, practical on-ground strategies for the rehabilitation of native fish populations are being achieved in the Murray River. This work is securing the long-term conservation of fish communities in the Murray-Darling Basin. Further monitoring and assessment will continue during the final 3–4 years of the project to provide a sound scientific understanding of the benefits of using innovative fishway technology to ensure the long-term protection of riverine biodiversity.