Dead star fish have washed up at South Beach.
Department of Fisheries officers have collected samples of the dead star fish from South Beach and nearby beaches in North Coogee to try and determine what has caused the kill.
The stretch of coast includes a popular dog beach and Port Coogee jetty.
"The samples have been sent to the department's fish health unit for analysis," a Fisheries statement read.
"Results may take some time depending on the tests being undertaken.
"No other dead aquatic animals have been reported or sighted."
Fisheries will continue to monitor the area in the coming days and has warned the public not to collect, handle or move any of the dead starfish as they may contain high levels of bacteria.
People are also advised against swimming in the ocean near large numbers of dead fish.
The starfish kill follows hundreds of dead fish washing ashore at Cockburn Sound, around 10 kilometres south of South Beach, in November 2015.
Testing later revealed the fish died from a microscopic algae that bloomed during warmer temperatures.
I would also check for radio activity!