Scientists baffled by strange round objects thought to be a rare type of living algae
Visitors from outer space or a natural phenomena? Surfers and early morning walkers were stunned to find thousands of ‘alien eggs’ on a Sydney beach this weekend.
Locals in Dee Why, on the city’s North Shore, reported seeing a large number of the strange objects which had washed ashore overnight.
But rather than the green spheres being something from another planet, scientists explained they were a type of sponge-like seaweed that forms egg shapes possibly to protect themselves from predators.
‘Alien’ algae explained
The balls are thought to be an extremely rare species of filamentous green algae.
The living organisms are known in Japan as ‘Marumo’ and Cladophora ball or Lake ball in English, and are sometimes found in freshwater lakes in the Northern Hemisphere.
‘Aegagropilious’ describes the habit of free living algae (algae not attached to rocks) forming into balls.
Floating algae balls are thought to be brought ashore by warmer weather and the rough wave conditions.
It’s unknown why the algae forms into balls. One hypothesis is that a ball-shape helps protect the algae from hungry fish, another that it may help them roll back into the water and avoid drying out when they wash ashore.