A mass fish kill at a South West beach has prompted authorities to investigate.
From October 15, hundreds of fish including black bream, sea mullet and flat head washed up on Myalup Beach.
Officers from the Department of Primary Industries and Regional Development took fish and water samples for analysis.
"Laboratory analysis of fish from the beach and water samples from the beach and the Harvey diversion drain has not been able to determine the cause of this event, although nitrate levels may have been slightly higher than normal," a DPIRD spokesperson said.
"The water was also heavily stained with what appeared to be tannins, which are associated with decomposing organic matter and which can rapidly affect water quality parameters such as pH and cause stress to aquatic animals."
In the meantime, people are reminded to stay safe around fish kills.
People should follow the general Department of Health 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;
• not to handle, collect, relocate or use dead fish for bait or consumption because of the risk of high levels of bacteria, and the potential for infection through handling or ingestion; and
• not to allow pets and other animals to come into contact with dead or decomposing fish either in the water or on shore.
Anyone who has handled dead or dying fish and experiences any inflammation on their hands around any cuts or abrasions should see a doctor.
Fish kills should be reported to FishWatch on 1800 815 507.
More information on fish kills can be found on the Fisheries website at www.fish.wa.gov.au.
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