Marine pollution is probably not the first thing that comes to mind when you think about golf. But 18-year-old student Alex Weber is hoping to change that.

She’s been collecting golf balls from the ocean for the past two years. So far, she’s accumulated more than 50,000 balls.

“If you were playing golf on this beautiful golf course and looked out and saw the entire surface of the ocean covered in golf balls, people would be outraged,” Weber said. “But because these golf balls are on the bottom of the ocean and you can’t see them, we just don’t know about it.”

That's because a good majority of golf courses are located on the coasts, where golf balls easily end up in the ocean. Once they've sunk to the floor, they wear down and release microplastics into the water.

“Those microplastics are consumed by the lowest level and up the trophic level, they aggregate into the larger animals which we end up eating,” Weber said, telling VICE News that she would like to see some kind of legislation that requires golf clubs to clean up after themselves.

VICE News followed along with Weber as she collected balls from the ocean to show how something as ostensibly harmless as the game of golf can produce so much pollution.

This segment originally aired July 31, 2018 on VICE News Tonight on HBO.