A Ballina councillor says the endemic north coast weed water hyacinth could be used strategically to remove excess phosphorous from Lake Ainsworth.
Cr Jeff Johnson said a recently completed Ballina Council report into the water quality in Lake Ainsworth revealed that phosphorus levels have increased by approximately 100 per cent over the last 20 years.
He added that the higher levels of phosphorus in the lake increase the frequency and severity of algal blooms, including blue green algae.
‘I was successful in getting the council to investigate the source of and feasibility of reducing the level of nutrients (i.e. phosphorus) in the water at Lake Ainsworth to improve the long-term health of the lake,’ Cr Johnson said in a letter to constituents.
‘Some possible reasons include an increase in sunscreen use (which contains phosphorus), urine, or leaking sewage pipes.
‘Identifying the cause is crucial to reducing the future impact that increasing nutrient levels will have on the long-term viability of this important natural area and its safe use for swimmers,’ Cr Johnson said.
He went on to praise Lennox Land care volunteers, who have been removing water hyacinth from the Lake, ‘which grows vigorously in the nutrient rich water.’
But he noted that water hyacinth ‘does remove phosphorus and other nutrients from the water and its removal might be able to be coordinated in a way that increases its ability to remove additional phosphorus.’
‘The key is to ensure that it is removed before it produces seed.
‘Lake Ainsworth is one of the jewels on the north coast and Ballina Council needs to do all it can to ensure its long-term health so that it can continue to be a swimming and recreation area long into the future,’ Cr Johnson said.