The white discs began surfacing on southern Italian shores about a month ago, according to the group, which campaigns to clean up Italy’s beaches.
Clean Sea Life said it received the first report from Paestum beach, in Campania, on February 21.
Since then, millions have appeared along the Tyrrhenian coast, said the group, which has been recording the sightings and alerting regional authorities.
Some of its members collected 800 of the discs in one hour on a single beach.
It is not known where the discs have washed in from or how so many of them ended up at sea, but it is believed that they are parts for a water purification plant that were either washed out during heavy rains or somehow fell into the ocean while they were being delivered.
Oceanographers are studying the log of sightings to try to determine where the spill most likely occurred.
They suspect it was somewhere in the Gulf of Naples and that currents later swept the discs north.
The group is urging members of the public to inform them if they spot more discs and, even more importantly, to pick them up.
“If it had been done right away, we wouldn’t find ourselves with hundreds of sightings of discs all over the Tyrrhenian a month later,” Clean Sea Life said.
“If we don’t pick them up now, they’ll continue to pollute our sea forever, breaking up bit by bit into smaller and smaller pieces without ever disappearing completely.”
With ANSA/The Local it.