This child swam in a pool filled with plastic bottles during The Plastic Ocean Swimming Challenge to raise awareness of what the oceans could be like if no action was taken to stop pollution.
The event was part of a campaign to mark World Oceans Day in Bangkok last Saturday.
In 2009, the United Nations General Assembly designated June 8 as World Oceans Day.
This month, the group launched Play It Out - a global campaign against plastic pollution that includes a music festival.
"Today, 13,000,000 tonnes of plastic leak into the oceans every year, among other damage, killing 100,000 marine animals annually," the UN said in a statement.
"From plastic straws to plastic bags, we all are at the front line of efforts to #BeatPlasticPollution."
More than 1,000 related events are being held around the world this year, including film screenings and cleanup activities.