Two photos captured by a Floridian wildlife photographer depict the shocking reality of pollution in the world's oceans.
Birdwatcher Karen Mason took the photos of a skimmer chick on St Pete Beach in Florida on June 20.
"If you smoke, please don't leave your butts behind," Mason captioned the image on her Facebook page.
A number of social media users have called the photos distressing, heartbreaking and disheartening.
Actress Pamela Anderson shared the photo on her Twitter, reiterating Mason's urgent warning for smokers to stop leaving their butts behind.
Cigarette butts are the most commonly discarded piece of waste worldwide, reports the World Health Organisation.
Butts are made from cellulose acetate, a type of plastic fibre. Each filter can take years to break down.