Sweetwater Fishing Forums
General Category => News Views & Press Releases => Topic started by: Editor on October 16, 2012, 06:47:08 PM
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Disease and fungus likely causes of fish deaths
15 October 2012 - Qld Dept of E&HP
An investigation by the Department of Environment of Environment and Heritage Protection (EHP) into fish deaths at Lowood has found a disease-causing parasite and a freshwater fungus are the likely causes.
Executive Director Andrew Connor said a thorough investigation had been undertaken following the death of approximately 8000 fork-tailed catfish in the Brisbane River near Lowood in September.
“Extensive field inspections and laboratory testing of the catfish and water quality in the area has found the most likely causes of the catfish deaths are infections caused by the parasite Ichthyophthirius multifiliis, commonly known as white spot disease, and a freshwater fungus,” Mr Connor said.
“Fish samples taken from the river showed damage to the gills and skin of the fish which is consistent with symptoms of white spot disease.
“Catfish was the only affected species and white spot disease is known to cause high mortality in catfish.
“Laboratory testing also excluded pesticides and toxic algae from involvement in the fish kill.
“The investigation was conducted by EHP in consultation with the Department of Science Information Technology, Innovation and Arts and Department of Agriculture, Fisheries and Forestry.
“The department has received no further reports of dead fish in the area.”
Mr Connor said excellent support had been provided by a number of agencies and volunteers to assist with the clean up.
“Somerset Regional Council, SEQWater and a number of volunteers did a magnificent job in completing the massive clean up operation and disposing of the dead fish.”
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I hypothesise, but Lake Wivenhoe rolls, and colder than normal water is released through the hydro valve dropping water temperatures in the river dramatically. Catfish high tail it up Lockyer Creek to warmer water. Dramatic overcrowding exaggerates the already present fungal and white spot infections and fish die in their thousands. This is the only thing that would explain the huge numbers of dead fish in the bottom of Lockyer Creek and the total lack of dead fish upstream of the junction.
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The question that now needs to be asked, IMHO, is what stressed the fish to the extent where the fungal infection / parasites could hit so many fish in such a concentrated area, yet not further downstream.
My thoughts are cold water release from the Wivenhoe Dam...... aka thermal colution.