Releasing balloons en masse into the sky to mark funerals and other ceremonies is killing birds, say scientists who have called for the practice to be banned.
"Balloons are a huge threat, not only to birds, but turtles and other marine life," said Fiona Maxwell, campaigner with the Australian Marine Conservation Society.
"It certainly is time for us to come up with less polluting ways to celebrate."
Dr Jenn Lavers, a biologist at the Institute of Marine and Antarctic Studies, in Hobart, says she finds balloons "in about one in 20 of every seabirds I examine".
Performing an autopsy on a shearwater, Dr Lavers extracted the remains of a purple balloon from it's gizzard.
"It was a beautiful bird, about 80 or 90 days old," she said. "But after it died and I cut it open, this purple balloon just exploded out of it."
Worse, in the same wedge-tailed shearwater's oesophagus, she found the remains of another, white, latex balloon.
"These were blockages for its whole digestion," said Dr Lavers, a research fellow at the Institute of Marine and Antarctic Studies, in Hobart.
"When its mixed in with stomach juices, the stuff becomes horrible, almost like chewing gum, and it just blocks them up.
Even those in the balloon industry say it's time to end the sight of massed balloons floating away at occasions such as funerals or sports celebrations.
"I believe the days of the balloon release are over and done with," said Maureen Egan, president of the Balloon Artists and Suppliers Association of Australasia.
"Whatever goes up, comes down, and is going to be litter," Mrs Egan said. "It's awful to hear about cases like this bird's."
Mass releases of helium-filled balloons still mark high profile occasions, such as the funeral of the murdered Leeton school teacher, Stephanie Scott.
Regulation is sparse. New South Wales is the only state to limit the number of balloons at a release to 19. But Mrs Egan, from Wharoonga in Sydney, said this was poorly enforced.
"You can't stop a person from doing a release," she said. "They will find the balloons and a cylinder (of helium) from a party supplier. What you've got to do is come up with environmental education."
Her association's members create fixed balloon displays, and are developing a campaign to advocate that balloons be popped and disposed of, after use.
"Pin it and bin it," she said.
Alternatives to mark occasions have been suggested, such as the release of white pigeons, or blown bubbles.