Hon Mia Davies MLA

Hon Mia Davies MLA

Former Minister for Water; Sport and Recreation; Forestry

    Monitoring to help prevent Vasse fish deaths

    30/01/2014 12:00 AM
    • Increased monitoring to detect ‘aquatic stress’
    • Earlier response and intervention for algal blooms and fish deaths

    Upgrades to water monitoring equipment in the Vasse-Wonnerup estuary will provide authorities with earlier detection of possible algal blooms and fish deaths, Water Minister Mia Davies said today.


    “In the next fortnight the Department of Water will install new data loggers to improve water quality monitoring in and around the Vasse-Wonnerup estuary,” Ms Davies said.


    “The monitoring is a central part of our fish kill mitigation strategy and response plans for this summer. The program was set up as a direct response to last April’s fish deaths and is an inter-agency initiative with the Vasse Estuary Technical Working Group.”


    When low dissolved oxygen levels are detected in the Vasse-Wonnerup estuary a number of responses can be triggered including opening the floodgates, opening the Wonnerup Inlet bar (if it is closed) and installing pumps to circulate water and improve dissolved oxygen levels.


    “Knowing the oxygen levels at key locations means the department and its partners will be able to take early action to prevent major fish deaths during times of aquatic stress,” the Minister said.


    Ms Davies said increased monitoring by the department, which started in November 2013, had revealed the system was generally coping well with the summer conditions and reduced river flow.


    “Weekly monitoring from upstream of the floodgates shows dissolved oxygen levels have fluctuated and declined during periods of hot weather, but remained above the level that triggers further actions,” she said.


    “The department and the Water Corporation opened up the Wonnerup Inlet sand bar before Christmas.  Analysis shows the estuary on the sea side of the floodgates is mixing well and maintaining water quality.”


    The Minister said the Vasse-Wonnerup and Geographe Bay catchment waterways had received the benefits of above average rainfall in 2013.


    “The risk of fish deaths increases as the weather gets hotter because they are generally sparked following summer rains when nutrients are washed from the catchment into the estuary,” she said.


    “The upgraded monitoring equipment will help ensure a timely response if any fish deaths do look likely to occur.”


          Fact File

    • Vasse Estuary Technical Working Group comprises the departments of Water, Parks and Wildlife, and Fisheries; Water Corporation; and the City of Busselton and is set up to manage the frequency and reduce the severity of fish kills in the system
    • The independent review, conducted by Professor Barry Hart, started in October 2013 to assess and make recommendations on waterways management in the Geographe Bay catchment
    • The report is due in March 2014
    • More than $4million worth of work recommended under the Vasse-Wonnerup Wetlands and Geographe Bay water quality improvement plan has been completed or is under way by the Department of Water and GeoCatch to reduce nutrients and untreated organic matter entering the system from land, rivers and drains

     Minister’s office - 6552 5500