WA Water Minister Terry Redman has announced that an independent expert will be appointed to undertake a review of the quality of local waterways.

The move follows community concern over an incident in April which saw more than 7,000 fish deaths near the Vasse River floodgates.

The incident resulted in the largest mass death of fish in the estuary at any one time.  It is believed the fish perished as a result of loss of oxygen due to the poor state of the estuary. Other water species such as crabs also died in the incident.

The mass fish death is the third such event to occur in the estuary in just the past five years.

Low flows, poor water quality and phosphorus were the likely cause of the fish deaths according to Dr Kath Lynch of the Department of Water. Along with warm weather and a dry summer following particularly low inflows in 2012 – the fourth lowest on record – this created conditions that can lead to fish deaths.

Busselton city’s environmental services manager Greg Simpson said the management of the Vasse Wonnerup waterway was shared between the Water Corporation, Department of Water, Department of Fisheries and Department of Environment.

“Each of these agencies has a different focus in terms of management, which means there is no one agency with sole responsibility. The problem is we have Water Corp focusing on the levels of the water because they’re thinking in terms of flood mitigation, but they are not thinking about the health of the river and the health of the fish,” Simpson said.

Following recommendations from a stakeholder workshop, Redman conceded there was a need for an independent review of management systems. He said the Department of Water would soon meet with key stakeholders to begin the process of commissioning the review.

“Major fish deaths have been reported in the Vasse-Wonnerup system since 1905, however reducing the frequency and severity of fish deaths and algal blooms in the system is a community goal,” Redman said. “Water quality data collected by the department has identified reductions in nutrients entering the wetlands as a result of focused on-ground works in urban and rural areas.”

“However, further nutrient reductions are required in some sub-catchments to achieve significant improvement in water quality.  The results to date are promising and hopefully the outcome of this review will identify priority actions to further this progress.”

The review will look at current management programs and make recommendations on the best action required to address the issue of water quality in the Geographe Bay catchment.

Since 2010, nearly $4 million in fertiliser management, fencing and urban stormwater retro-fitting has been completed or is currently being implemented in the Vasse-Wonnerup catchment by the Department of Water, GeoCatch and project partners.

The review is expected to take around six months to complete and will include consultations with local key stakeholders including the City of Busselton, Vasse Wonnerup Water Quality Workshop group, GeoCatch and South West Catchments Council.