Thick white mousse washes up on Biarritz beaches

The beaches of the town (Pyrénées-Atlantiques) - as well as any cars parked nearby - were covered in a white layer of mousse, which has the appearance of shaving foam, or even snow.

Local magazine Surfing Biarritz was the first title to take pictures and post videos of the phenomenon, listing the incredible shots on its Facebook page.

The beach is still fenced off after the orange alert meant that residents were advised to remain away from the coast and to not walk near the sea.

Yet, the white waves were clearly visible regardless, and much of the mousse easily came through the barriers onto the street behind.

The white foam - also known as “spume” - is a natural phenomenon, and not necessarily evidence of pollution or anything sinister (especially if it is pure white). It is said to be created when seawater is subject to significant movement or agitation, and when it contains just the right amount of minerals, primarily from offshore algae.

The foam is then formed by the churned-up water, and due to its light weight and easily-blown texture, often ends up on beaches or inland.