Dpi Monitoring Richmond River Water Quality Following Fish Kill

[Ken A]

NSW Department of Primary Industries (DPI) is closely monitoring water quality in the Richmond River following the discovery of more than 300 dead fish at Wardell.

DPI Director General, Mr Barry Buffier, said that following recent flooding rains in the Richmond catchment dissolved oxygen in the Richmond River below Corakai had fallen to levels lethal to fish.

“DPI and local government officers have been monitoring water quality in the river over recent weeks,” Mr Buffier said.

“Dissolved oxygen levels between Broadwater and Corakai have been below 2 milligrams/litre for the past two weeks.

“Levels below 2mg/L generally results in the death of many fish species and on Wednesday DPI officers observed more than 300 dead fish and others gasping for air on the river surface.

“The affected fish included adult and juvenile bream, flathead and garfish along with a number of juvenile eels.

“More dead fish have been reported at Wardell today and further monitoring by the Department indicates that dissolved oxygen levels are now below 0.5 mg/L between Pimlico and Woodburn, 1.0mg/L at Ballina and 2.2mg/L at the river mouth.

“It is possible that more fish deaths may occur as a result if the fish are unable to move to areas of better water quality.”

Mr Buffier said the decline in water quality was the result of the recent heavy rains combined with high temperatures.

“Rotting vegetation in wetlands along the coastal floodplain and the high temperatures lower the dissolved oxygen in wetland waters which can drain quickly to the river following heavy rainfall,” he said.

“Since a major fish kill in the Richmond River in 2001, DPI has been working closely with landholders, local government and the catchment management authority to progressively rehabilitate floodplain waterways in several north coast river systems, including the Richmond.

“This work has included infilling a number of drains and laser levelling the surrounding land to minimise the impact of the drainage system on river water quality.

“Also, more than 600 kilometres of floodplain waterways have been reopened to tidal flow to improve general water quality and fish passage.

“This is a long term challenge and DPI will continue to work with landholders and other authorities to upgrade the floodplain waterways and minimise the potential for major fish kills.

“In the meantime, we will continue to monitor the current situation.”

Media contact: Bill Frew on 02 8289 3922 or 0429 144 776.