In 1971, marine biologist Edward Carpenter made a shocking discovery, finding small bits of plastics floating thousands of miles off the east coast of America, in the Atlantic Ocean.
More than 50 years later he tells the story of how he had to fight hard to get the scientific world to take notice of his discovery.
Listen to more from Edward Carpenter on Witness History: History as told by the people who were there.
Correction 16th January 2023: The article originally included a picture of a Hawksbill Turtle swimming underwater while entangled in a plastic bag. However as this was a concept picture, and the bag was not present in the original photo, we have replaced this image.