Mysterious tar balls washing up in Sydney have forced the closure of seven beaches, including Bondi, but authorities are yet to identify where they are coming from.
Clovelly beach and the northern end of Maroubra were closed on Thursday when more tar balls were found after Gordons Bay and Coogee beaches were earlier closed by Randwick council. People have been warned not to touch or go near the debris.
Bondi, Tamarama and Bronte beaches were also closed “out of precaution”, neighbouring Waverley council said in a statement on Thursday afternoon.
Randwick council said on Wednesday evening that preliminary test results had identified the dark spheres as “tar balls” – which are formed when oil comes into contact with debris and water, usually as a result of oil spills or seepage.
The council testing showed the debris was a hydrocarbon-based pollutant – the chief component of petroleum-based products.
Council employees on jetskis spotted a suspected oil slick out at sea on Wednesday morning, the Randwick council mayor, Dylan Parker, said at the time.
However, the Port Authority of NSW said no oil spills had been reported by vessels.
“We don’t yet know what has happened to produce the debris washing up on our beaches,” Parker said in a statement on Thursday. “We will continue to work with relevant authorities to ensure the safety of the public and clean up our beaches.”
The four Randwick beaches were closed until further notice.
Waverley council said it had closed its beaches after the environment watchdog formally notified it that “pea to marble-size balls of light grey-white colour were observed by EPA staff on Bondi, Bronte and Tamarama beaches”.
“As a precaution, all Waverley beaches will be closed until further investigation has been carried out by the EPA and relevant government bodies,” the council said.
The New South Wales premier, Chris Minns, said eastern suburbs beaches had been closed “out of an abundance of caution”.
He said the public would be kept updated on the investigations being led by the Environment Protection Authority.
“We need to make sure that we’re fully investigating,” Minns said. “It’s an unusual occurrence on Sydney’s beaches. The EPA is leading those investigations. The council is responsible for closing down the beaches.”
The EPA said in a statement that balls had also been observed at Congwong, Frenchmans, Little Bay and Malabar beaches.
“At this stage, the origin and contents of the balls remains a mystery,” the watchdog said on Thursday.
“But the EPA is conducting extensive testing on a number of samples. While we understand initial Randwick city council testing suggests the presence of hydrocarbon, at this stage EPA tests cannot confirm the contents.”
Stephen Beaman, EPA’s executive director of regulatory practice and services, told reporters on Thursday that their test results were matching up with those of Randwick council.
He said the material was “fibrous” and “unusual”.
“We are actually seeing, as we move away from the Coogee area, the size of the balls are getting smaller,” Beaman said. “Probably getting a lot of wave action in the surf zone, breaking that material up.”
The EPA said until the clean-up was concluded “we advise against swimming and touching any balls that may have washed ashore in the identified areas”.
NSW Maritime took over coordination of the incident on Thursday. Its director, Darren Wood, said the organisation would be working with Randwick council, the EPA, the port authority and the Australian Maritime Safety Authority (Amsa).
“We’ve had vessels out on our water. We can ensure that we can’t see any more sheen on that water,” Wood told reporters in Coogee on Thursday.
“We also can’t see any more balls that are drifting in towards the beaches of the city, which is a good sign at the moment.”
NSW Maritime was working with Amsa to find the source of the debris.
“They will do reverse modelling and drift modelling, taking into account the currents and wind, for us to be able to work out whether it comes from south, north or east of NSW, to try and give better information on the likely source,” Wood said.
Parker said Randwick council staff had been working with the EPA, port authority and Transport for NSW on the clean-up response.
“Our community is rightfully very protective of our natural environment and this has been a very concerning incident,” the mayor said on Wednesday.
“We have engaged an expert occupational hygienist and a specialist waste removal contractor who are currently systematically removing the debris from the beaches in accordance with an agreed safe work method statement developed with the NSW EPA.”
Louise Morris, the oil and gas campaign manager at the Australian Marine Conservation Society, has said tar balls are usually formed after an oil spill when petroleum is washed in waves and currents, making it condense and coagulate.
“The more it keeps gripping on to other substances, it solidifies and condenses,” Morris said. “Part of that process of washing through the ocean means that they form a spherical shape.”
Any oil spill can be harmful to marine life but Dr Sharon Hook, CSIRO’s principal research scientist, said Sydney’s beaches would be safe for people once the tar balls were collected and removed.
They “are filled with carcinogenic compounds so you wouldn’t want people to come in contact with them,” she told ABC radio.
“[But] as soon as it [the beach] is cleaned it will be safe because the chemicals and tar stick together. Oil and water don’t mix … so when the beach is reopened it will be fine.”
This article was amended on 17 October 2024 to correct Stephen Beaman’s name and title.
