Warm on land temperatures could result in natural fish kills this summer.
While fish kills are typically more common during warmer weather, with an El Niño summer bringing with it extreme temperatures, PIRSA is warning that fish kills are likely in shallow waters (freshwater, estuaries and marine tidal flats).
A fish kill is a sudden and unexpected mass mortality of fish or marine organisms. There are a range of causes, including water quality changes, pollution and infection, however most fish kills are the result of natural events and changes in the local environment.
Fish in smaller sized waterways such as dams, ponds and smaller creeks or in parts of estuaries or waters where tides and currents can isolate fish populations are particularly susceptible. This exposes them to high water temperatures and consequently lower dissolved oxygen levels that increase the risk of a fish kill.
PIRSA, through the department’s Biosecurity SA and Fisheries and Aquaculture divisions, are responsible for investigating fish kills in SA, and urge the community to report fish kills.
Detections of large numbers of dead fish or other aquatic animals, should be reported to the 24-hour Fishwatch hotline on 1800 065 522. Information to report includes:
- the location of dead fish
- your name and contact details
- the species of organisms involved or a description if unknown
- the number of dead organisms
- size of area affected
- when it occurred, if known
Water users are also reminded that dead or dying fish should not be eaten as they may present a health risk due to their poor condition, possible infection or contamination.