Gardeners 'at fault' for algal bloom

The hideous build-up of yellow algae in the Leschenault Estuary could be the fault of residents in the region, according to ECU natural sciences associate professor Dr Mark Lund.

Dr Lund speculates the run-off from farmers along the Collie River might not be the major cause of the algal bloom in the waterway.

He said the blame could sit with residents not paying enough attention to their gardening habits.

“Unfortunately it doesn’t take much for a bloom to occur if the conditions are right,” Dr Lund said.

Dr Lund said it was hard to pinpoint the cause of the bloom, but attributed it to a number of nutrient sources, such as farming, the golf course and development along the Brunswick and Collie rivers.

He said growth in Kingston, Treendale and Eaton and the associated gardens were likely to be at fault.

“What you put in the garden can enter the ground water in places near the river,” Dr Lund said.

“Any fertiliser which is not absorbed could be washed into the drains.

“It could just be a small spike, but that is enough to start the bloom, which then supports itself.”

Dr Lund said the problem could be solved if residents and farmers paid more attention to how they handled their properties.

According to the Department of Agriculture and Food WA website, there are several possible strategies to alleviate the issue, namely using low or slow-release phosphorus fertilisers.

Department of Water regional delivery and regulation executive director Paul Brown agreed that following the Leschenault Water Quality Improvement Plan was the best option to protect the estuary.

“The plan sets out a number of management actions to improve water quality, including reduced urban nutrient use, horticultural best-management practices, improved irrigation and fertiliser practices and improved effluent management of dairy sheds,” Mr Brown said.