TONY Whitehorn was met with a surprise as he gazed upon the Airlie Beach foreshore from his balcony this morning.
A mass of brown could be seen floating within the water moving in the direction of the shore.
Cruise Whitsundays Marine Operations supervisor John Dyson said the discolouration could be attributed to a Trichodesmium algae bloom.
"(It is a) naturally occurring algae at this time of year which consumes oxygen within the ocean and rises to the surface as a brownish/black colour," he said.
Trichodesmium algae is commonly mistaken for coral spawn with subtle differences in colour, shape and smell.
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