A cleanup in Sunshine Coast, Australia recently uncovered a decades-old plastic bag from the depths of the ocean, belonging to a famous fast food chain.

The find once again, demonstrates the true pervasiveness of plastics in the marine environment.

Plastic bag likely from the 1970s or 80s

Elliot Peters, a scuba diver who also runs a community group called the Sunshine Coast Clean Up Divers (SCCUD), shared the find on Facebook on May 17.

Every month, the group conducts underwater cleanups and surveys at two waterways.

A group of volunteer divers from SCCUD surveyed an eight metre-deep stretch of water off Bulcock Beach.

One item among the nondescript pile of trash stood out -- an almost intact plastic bag featuring the distinctive face of KFC's Colonel Sanders.

Peters added that it was "almost fully intact when it was discovered underwater, half full of silt and tangled in rocks."

Older than most of you reading this

According an ABC News article on June 13, Peters then sent a photo of the bag to the fast food chain.

Shockingly, KFC revealed that from the logo and design, the bag was estimated to be around 30 to 40 years old.

Despite plastic bags being flimsy and paper thin, the fact that it could have survived in such a "harsh environment", with minimal wear and tear, is a testament to the durability and longevity of the material.

Till now, it is uncertain how long the lifespan of a plastic bag is before it degrades. Estimates have ranged between 10 and 1,000 years.

Location is a popular, scenic destination

From a quick Google search, it seems that the place where Peters fished the KFC plastic bag out from is a popular beach with locals, known for its scenic "sparkling blue waters".

And from Peters' photo, it seems the website was right—the waters of Bulcock Beach look clean and blue, with no hint of murkiness.

However, it seems that this sparkling facade belies the trash that lurks beneath the surface.

This was one of the group's hauls of trash.

Peters wrote that in the 18 months that SCCUD had surveyed the same area along Bulcock Beach, the group had collected 500kg of trash, including almost 20km of fishing line.

He also stated that him and the other divers were hardly able to move on from the same underwater stretch before trash accumulated again.

"Sadly we are barely able to cover even 1000 square metres before we need to start again in the same spot, there are areas with dozens of tyres and cobwebs of fishing line that we would love to clean up but we just don't have the time."

You can view Peters' original Facebook post here:

Top photo from Elliot Peters / FB