Gibraltar has banned the release of helium-filled balloons in a bid to lower the number of marine animals killed by swallowing them.

“The government has published regulations to ban the deliberate release of gas-filled balloons,” the government of Gibraltar said in a statement.

The British overseas territory, on Spain’s southern coast, said the move would “reiterate its commitment to clean seas, free of plastics and other non-biodegradable materials which cause so much harm to wildlife”.

It comes two years after the government ended the traditional release of 30,000 red and white balloons on Gibraltar’s National Day celebrations on 10 September.

The balloon ban was introduced following years of campaigning by the Gibraltar Ornithological and Natural History Society and other local wildlife organisations, according to The Local in Spain.

“Balloons are mistaken for food by many species of wildlife, especially turtles. Once balloons have been eaten they can block digestive systems and cause animals to starve. The string on balloons can also entangle and trap animals,” the society said in a statement.