Severe weather off the east coast of Australia has left beaches in the Northern Rivers region of New South Wales and on the Gold and Sunshine coasts covered in a thick layer of sea foam, attracting crowds of curious locals, and, at least potentially, venomous sea snakes. 

News.com.au reports that the foam went viral across the globe after a local Byron Bay woman interrupted a live weather update to search for her missing dog, Hazel, who was later rescued from the mess. 

According to the National Oceanic and Atmospheric Administration (NOAA), sea foam forms when organic and artificial matter in the ocean is agitated by wind and waves.

And while the foam itself is usually harmless and non-toxic, it turns out the substance – which is also known as “spume” – can contain a string of hidden dangers.

Experts warn that the greatest danger may be venomous sea snakes, which can be concealed beneath the foam. In 2015, Far North Coast surf lifesaving director Ben Redman told The Northern Star people “shouldn’t swim in it. You’ll usually find a lot of sea snakes in the foam, they seem to be attracted to it,” he told the publication. Mr. Redman claimed that in 2008, 21 snakes were counted during a foam event at Ballina’s Lighthouse Beach.

Dog rescued from sea foam as huge swells and rain batter Australian coast