The naturalist David Attenborough, 93, appeared onstage at the Glastonbury festival in England on Sunday to praise its ban on single-use plastic bottles, delighting festivalgoers who have instead lined up for tap water.

Attenborough’s “Blue Planet II” documentary, which has been shown in countries around the world, highlighted the dangers of plastic pollution to marine life, and he said the move at one of the world’s largest festivals would have an impact.

“That is more than 1 million bottles of water that have not been drunk by you in plastic,” Attenborough said to cheers and applause. “Thank you, thank you.”

Growing calls for action by the public in part prompted around 180 countries to agree last month to sharply reduce the amount of plastic that gets washed into the world’s oceans, the United Nations said.