Signs warn swimmers to keep heads above water in Moore River at Guilderton due to amoeba risk

Amoeba warnings sign in Guilderton.
Amoeba warnings sign in Guilderton.


SIGNS urge swimmers to keep their heads above water in the Moore River at Guilderton.

In its January community notice, the Shire of Gingin reminded people “heading to rivers and estuaries – including the Moore River area – for the holidays to be mindful of amoeba risks”.

“Swimmers should be aware that when water temperatures rise above 20 degrees, amoeba organisms may be present, particularly in shallow waters,” it said.

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“Minimise the risk by keeping your head (and your children’s) above water.”

According to information from the Department of Health, supplied by the Shire, Moore River was one freshwater system in WA tested for amoebae, including Naegleria fowleri organisms.

That is responsible for the “extremely rare but fatal disease amoebic menigoencephalitis”, commonly known as amoebic meningitis.

“The Department of Health and the Shire of Gingin, along with other managing authorities, will be collecting water samples this swimming season from the Moore River,” the department said.

“They will also provide sanitary inspection activity updates to assess faecal pollution risks and provisional bacterial water quality classifications for each site that is sampled.

“Sample results for the Moore River carried out to date have indicated low level of thermotolerant coliforms and thermophilic amoebae.

“The presence of thermotolerant coliforms nearly always indicates faecal contamination.

“The presence of thermophilic amoebae is generally the precursor to conditions suitable for amoebic meningitis.

“Whilst this amoebae has not yet been identified in the Moore River, precautionary signs have been erected in prominent locations along the foreshore advising swimmers to keep their heads above the water and no jumping into the water and forcing water up the nose.”

The department said water monitoring allowed authorities to make sure water was safe to swim in and issue warnings when pollution occurred.

“Bacteria in water can come from a number of sources including farming activities, domestic animals, human effluent and wildlife,” it said.

“Swimming and/or swallowing water contaminated with high levels of bacteria can put you at risk of illness such as gastroenteritis, skin irritations, or respiratory, ear and eye infections.

“It is important to be aware of the common causes for high levels of bacteria in natural waterways so you can avoid swimming and other similar recreational activities during these times.”

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