See Blanket of Jellyfish Washed Ashore
In New South Wales, 45-year-old Brett Wallensky posed for pictures with a carpet of aquamarine bluebottles, also known as Portuguese Man-of-Wars, when he was walking along the rocks at Barlings Beach with his partner Claudia. With every wave, more of the common jelly-like creatures splashed up onto the rocks, reported StoryTrender. Despite their vibrant color and balloon-like bodies, Wallensky called the scene "the stuff of nightmares."
With their potent venom, even dead jellyfish, which are similar to this species, washed up on land can still sting.
Because they frequent warm waters, the species is fairly common in Australia. Last summer, disgruntled beachgoers reported the area was overrun with the creatures, though the cause of them coming up on land is not known. These jelly-like organisms are actually siphonophores, which means that rather than being a single creature, they're colonial organisms composed of individual "zooids" that each have their own functions.
In general, jellyfish and related organism numbers are on the rise. This might be caused by climate change, the University of British Columbia's Lucas Brotz tells Mother Jones, but it's difficult to tell. Much of the world's water is warming, becoming prime habitat for these creatures, but "there's a lot of noise in the signal," Brotz says.
This story has been updated to reflect that Portuguese Man-of-Wars are not true jellyfish.