Fish Kill Events

The number of fish kill events appears to be stable between 2000 and 2017 with between zero and three events per year in rivers and estuaries across the South West NRM region. The exception to this was 2015 when six events occurred, however no events were recorded in the last two years (2016 and 2017). Many of these events were linked to poor water quality due to a number of man-made changes to rivers and their catchments including increased nutrients, clearing of riparian and catchment vegetation and reduced flushing of rivers due to installation of barriers and changes in flow.

Work being done

DWER and DPIRD coordinate efforts across state and local government in responding to fish kill events, based on the state fish kill response protocol.

There is also considerable work going on to better understand and manage fish kill events, for example the fish kill mitigation and response plan for the Vasse Wonnerup System.

Further information

Fish kills events are where 10 or more fish are reported in an area. The indicator does not include events caused by natural conditions (e.g. life-cycle events such as mortality of adults following spawning, e.g. pouched lamprey) or from dumping of by-catch (unwanted species caught during fishing).

> State fish kill response protocol

> Fish kill mitigation

> Fish Kill response for Vasse Wonnerup

Calls to action:

Fish kill events are typically associated with poor water quality, for further information see Fish kill events – factors contributing to fish kill and algal bloom events (DWER 2018).

Actions to improve water quality:

  • Reduce use and change the type of nutrients used in urban gardens and agriculture
  • Retain native vegetation around waterways and wetlands
  • Install fencing to exclude livestock from waterways

Rapid response is needed to understand the causes of fish kill events. If you see a fish kill please report it immediately to FishWatch 1800 815 507.

Case Studies

Data Source

  • Department of Water and Environmental Regulation (DWER). 2018.  Fish kill register.  Record of fish kill events in freshwater and estuarine waterways (not marine events) since 2000. (Note: marine events are recorded by DPIRD). [Accessed Feb. 2018].
  • Department of Water and Environmental Regulation. 2018. Fish kill events – Factors contributing to fish kill and algal bloom events. [online] Available at: [Link]. [Accessed Feb. 2018].