Beachgoers were greeted by an unusual sight along the west coast this week after the shoreline at some beaches turned reddish-brown in colour.
The tainted waters along beaches in Esperance, Western Australia came with a warning to stay away as the reddish water is harmful to humans and their pets — but alarmingly, it's more common than we might think.
Photos shared by concerned locals show the shoreline appear murky, with the usual turquoise water tainted by a tinge of red. The sand appeared stained where the water had washed ashore, leaving many locals questioning the cause.
Natural phenomenon at WA beach explained
What's being witnessed in WA this week is a natural phenomenon known as an algal bloom, the local council confirmed on Monday. "The algae is a naturally occurring event and was likely to have been swept in with winds and tides. It is expected to move away from the area in the same way it has done in the past," Shire of Esperance said.
In the meantime, the council urged members of the public and pet owners "to avoid the section of beach between Taylor St Beach and Port Beach". "The Department of Health [has] advised that recreational activities such as swimming, and shellfish collection be avoided in the area as contact with the bloom could result in skin irritation," they said.
Locals question 'disgusting' algae bloom
One WA local shared snaps of the water at Port Authority beach over the weekend. She said it looked "disgusting" and confirmed it wasn't seaweed.
"It's probably a red tide. An algae bloom, and it is toxic," one person suggested. "Happens every year... it's algae bloom," another confidently said.
Algal bloom witnessed in bodies of water across the country
The algae, more commonly referred to as red tide or sea sawdust, is easily identified by a yellow–brown surface scum with an oil-slick appearance. The surrounding waters may also change to a pink or sometimes pale green colour as it begins to decompose.
Trichodesmium algal blooms (another name for sea sawdust) occur sporadically at various locations along the state’s coastline and tend to be moved by ocean currents. But it's a phenomenon witnessed around the country in riverbanks and other watering holes too.
Last month, people were warned to stay away from a popular and vast mangrove area in Brisbane after one stretch of water experienced a radical change in colour. Earlier this year, some Sydney beaches were closed after a harmful algae was detected.
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