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Government of Western Australia - Department of Fisheries
Wednesday 11 December 2019

Findings for marine fish kill of tiny crabs at Karratha

​​Update to Fish Kill Notification
- 11 December, 2019 at 9.25am

Water sample results from the Phytoplankton Ecology Unit at the Department of Water and Environmental Regulation indicated some Cyanobacteria filaments were present in seawater and, while these strands were not at any density of concern, they have the potential to irritate or clog gills.

Report fish kills to the 24 hour FishWatch line on 1800 815 507.

Update to Fish Kill Notification
- 9 December, 2019 at 5.15pm
The collected crab samples were too decomposed for analysis in the Department of Primary Industries and Regional Development (DPIRD) laboratories. 

Fisheries officers from DPIRD are monitoring the situation, but no further reports have been received. 

Weather in the area remains extremely hot.
Report fish kills to the 24 hour FishWatch line on 1800 815 507.

Fish Kill Notification
- 26 November, 2019

Samples of tiny crabs, measuring between 5 to 15mm, have been collected for analysis, following the report of a fish kill on mudflats near Karratha’s Searipple Lookout.

Many thousands of the small dead crabs have been observed in pools on the mudflats, but it’s estimated only about 10% of the crabs in the area are dead and there are other animals, including other crustaceans, which appear to be unaffected. 

Mortalities of the tiny crabs have also been noted at some other nearby locations as well.

Along with the dead crab samples, water collected from the area will undergo testing, and have been transported to Perth to be examined.
Low tides in the area at present mean there’s less water movement on the flats. In addition, very hot 40+ weather conditions in the past few days and hot winds may have contributed to the deaths. Scum that may contain algae has also been noted on water in the small pools. 

Department of Primary Industries and Regional Development officers are monitoring the situation and updates will be issued, when further information is available. In the mean-time we urge people to stay safe by following the general Department of Health fish kill advice:

    • not to swim in areas of water with large numbers of dead and decomposing fish because they may contain high levels of bacteria and have an objectionable odour;
    • not to fish in water with large numbers of dead fish;
    • temporarily not to collect or consume fish from the waters near a fish kill;
    • not to collect and use dead fish for bait or consumption because of the risk of high levels of bacteria; and
    • not to allow pets and other animals to come into contact with dead or decomposing fish either in the water or on shore.

Fish kills should be reported to our FishWatch 24 hour hotline on 1800 815 507.

The Department of Primary Industries and Regional Development (DPIRD) is responsible for responding to fish kill events that occur in ocean environments.

The Department of Water and Environmental Regulation manages investigations on fish kills that occur in estuaries, rivers and naturally occurring inland water bodies.

In both circumstances, DPIRD’s laboratories carry out testing of any fish samples assessed as suitable for that purpose and this can take some time.  
More information about fish kills can be found on the department’s website at

Last modified: 12/12/2019 5:26 PM

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