Fish Kills

Fish kills are defined as a sudden mass mortality of wild fish.

Fish kills can occur at any time although data indicates fish kills are more likely to occur:

  • in hot summer days resulting in high surface water temperatures
  • following sudden changes in temperature (thermal stratification and de-stratification)
  • during or post an algal bloom
  • during hypoxic blackwater – when there is a lot of organic material washed into the river, its rapid decay can consume dissolved oxygen from the water. If dissolved oxygen drops to very low levels, this can cause ‘hypoxic’ water which can be stressful for native fish and can lead to fish kills.

Please report any fish death incidents or observations to the Fishers Watch Phone line on 1800 043 536 and/or Council.

Useful links