A couple of plastic bags estimated to be at least 40 years old have been found in mangroves in Brisbane.
The plastic bags which had barely degraded despite being submerged in the Brisbane River for at least 27 and 40 years, respectively, could be easily timestamped by their logos.
Conservation group World Wildlife Fund (WWF) as well as the Australian Geographic magazine shared the photographs of the supermarket bags that had been found by the University of Queensland’s research team, Turtles in Trouble.
The group which runs regular “surveys” of Queensland waterways to document the rubbish that ends up there said the two bags had been found during separate collections of the same area.
“We are in the middle of our 45 site survey of the SE Qld region [sic]. We found this retro Coles bag in the mangroves,” Turtles in Trouble posted to its Facebook page when the first bag was discovered in September last year.
Three months later, in December 2018, the group discovered a plastic bag thought to be even older in the same region. Like, the earlier find, its logo was still clear. Farmland was the name for Coles’ home brand range.
“Once again we found a very old plastic bag during our Qld surveys. I swear there is a rip in the space/time continuum at this location. It is constantly spitting out #RetroRubbish,” the group posted.
“Turns out it is the Coles home brand from between 1971 and 1979!”
Turtles in Trouble’s principal marine biologist, Dr Kathy Townsend, said about 30 per cent of sea turtles dying off the Queensland coast had been killed by plastic bags.
She explained that when sea turtles eat plastic bags they get “gut impaction”, which is where food can’t be digested so it creates gases in the animal.
“The gases move into the body cavity of the animal and make it positively buoyant,” Dr Townsend told ABC Landline last year.
“We call those ones ‘floaters’ and that’s quite common… and they very, very slowly starve to death, if they’re not hit by a boat first.”
Estimates vary on the time it takes for plastic bags to break down, but according to the United States Environmental Protection Agency, it ranges from tens to hundreds of years.