Pathology tests reveal Kimberley fish deaths caused by parasites
Released 13 Jun 2011
Fish pathology test results have revealed that the recent fish deaths in the popular swimming spot 'The Grotto' were caused by parasites that do not pose a risk to human health.
Approximately 40 fish were found dead or dying two weeks ago at the East Kimberley swimming spot near Wyndham.
Staff from the Department of Water and Department of Fisheries responded to the incident and carried out a series of water quality tests that found no algal blooms or toxic algae presence in the water.
Fish pathology tests from carcasses taken as part of the response plan have subsequently revealed the cause of death was as a result of parasite infestation of the fish gills.
"It is common for fish under stress to succumb to natural pathogens. The combination of low oxygen in the pool and the recent influx of organic matter from heavy rains has induced stress on the fish and provided a favourable environment for the growth of these pathogens," Department of Water Program Manager Duncan Palmer said.
"Fish pathology results indicated that parasitic infestation by ciliated protozoa and resulting thickening of the gills of the eel tail catfish are likely to have contributed to the fish death."
"These species of protozoa are naturally occurring in fresh water eco-systems and are not listed as being harmful to human health."
He said the pathology confirmation relates only to the eel tail catfish, as the samples of the Western Sooty Grunters were unusable due to the extent of decomposition.
"We know from our initial water quality tests that the water was poorly oxygenated to hypoxic which could have contributed to fish deaths particularly for individuals with gill damage," he said.
"The extra information on the cause of these fish deaths is available because we got to the kill site early before they all decomposed and could get good samples for Fisheries to conduct pathology tests.
"This highlights the value of the public notifying us immediately they see something suspicious like this in a waterway."
For further information or to report a fish kill or any other incident in waterway contact the Department of Water Kimberley region office on 91664100.
Contact: Peter Collins
Phone: (08) 6363 6848 / 0434 603 441