Environment Protection Authority Victoria (EPA) is advising of fish deaths as a blackwater event continues to occur in parts of the Murray River and its tributaries.
The advice comes after EPA was informed of a fish death incident near Kenley, located in the rural city of Swan Hill, of 12 golden perch due to dissolved oxygen levels.
Blackwater, often associated with flood waters, can see reduced oxygen levels in some Victorian waterways which may cause fish to die.
The Murray Darling Basin Authority has issued a statement advising river users of the blackwater event following recent flood events, stating that similar blackwater responses could also be occurring in other tributaries.
“Flood waters during spring have mobilised large amounts of organic matter, such as leaves and wood, from the forest floor and floodplain. This organic matter is now decaying, resulting in low dissolved oxygen levels which may in turn cause fish to die. River users may also notice dead or distressed fish as a result of the sudden drop in oxygen levels.
“Similar blackwater responses could be occurring in tributaries such as the Goulburn and Murrumbidgee valleys,” the statement reads.
EPA investigates reported fish deaths and works closely with the Department of Environment, Land, Water and Planning (DELWP), water corporations and catchment management authorities to manage fish death events.
Suspected fish deaths should be reported to the EPA’s Pollution Hotline on 1300 372 842 (1300 EPA VIC). It is important that reporters record any observations of pollution that may be a cause.
More information on blackwater can be found at www.mdba.gov.au/managing-water/water-quality/blackwater.