Like colorful corals, they rocked gently in the ocean current.

Only these were not beautiful natural reefs grown over centuries. They were plastic bags, stuck to the Aegean Sea floor since a waste site slid into the water eight years ago.

A team of divers and environmentalists pulled thousands of plastic bags from the water near Greece's Andros island this month. The workers described what they found as a "gulf full of plastic corals."

Volunteers of the environmental group Aegean Rebreath bring ghost nets from the bottom of the sea on their boat, off the island of Salamina, Greece, June 30, 2019. Picture taken June 30, 2019. REUTERS/Stelios Misinas

Seas polluted with plastic have become one of the most shocking signs of human damage to the planet.

"It was a very scary thing to see," said Arabella Ross, a volunteer diver with Aegean Rebreath. The group carries out underwater and coastal clean-ups.

"It really shook me and I think it really shook everyone who saw it," she added.

The Mediterranean is among the seas with the highest levels of plastic pollution in the world, the World Wildlife Fund (WWF) said in a report in June.

Greece produces about 700,000 tons of plastic waste a year, or about 68 kilos per person, the WWF said. About 11,500 tons enter its seas every year. Almost 70% of that returns to the Greek coast, one of the longest in the world.

The sea pollution off Andros is thought to date back to 2011, when heavy rain caused a waste site to collapse. Most of the waste fell into the sea.

Aegean Rebreath divers removed blue, black and yellow plastic bags caught between reefs and among fish.

It was "like the paradise of the Caribbean Sea, where you find coral reefs everywhere of every color. It was the exact same thing, but instead of corals it was bags," diver Arabella Ross said.

The team managed to remove only a small part of the plastic waste they found, she said.

They also pulled up 300 kilograms of old fishing traps – known as "ghost nets" – from Andros. In a separate operation in June off Salamina, a small island near Athens, they removed two tons.

"If people are wondering where their rubbish ends up, we see it each time we go into the water," Ross said.

Reuters news agency reported this story. Caty Weaver adapted it for Learning English. Kelly Jean Kelly was the editor.

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