When nature photographer Justin Hofman was out snorkeling off the coast of the Indonesian island of Sumbawa last year, he didn’t know he was going to stumble upon what could be the poster child for today’s marine trash crisis: a tiny seahorse latching onto a cotton swab.

The photo, which Hofman posted on Instagram, is now a finalist in the Wildlife Photographer of the Year competition from the Natural History Museum in London. In the post, Hofman said he wishes the photo didn’t exist. “I wish that this scene didn’t happen every day, that’s the thing,” he tells The Verge. “I spend a lot of time underwater all over the world, and I see trash and debris and human waste all over the place.”

Hofman says he’s been passionate about the problem of marine plastic pollution for a long time. He’s based in Monterey, California, but he’s an expedition leader for a company that takes people all over the world on wild tours. And he’s always talked to people about wildlife and conservation issues. Entering the photography competition has been a way to allow “a larger audience to come into the conversation I’ve been having for years,” he tells The Verge.

The seahorse in Hofman’s photo is just one example of how marine animals interact with plastic debris. Every year, tons and tons of plastic trash enters the ocean — shredding into pieces that are found virtually everywhere, from the surface to the bottom of the sea and on remote islands. Plastic pollution is dangerous for marine animals: birds and fish can die from ingesting too much plastic, and larger animals like whales and sharks can get tangled in fish nets and die. Some estimates say that by 2050, there could be more plastic than fish in the sea.

Hofman was in Indonesia for one of his expeditions. As he was snorkeling, the tide changed, he says, and the water started filling with all kind of debris — algae and wood first, then plastic. The tiny seahorse — about 1.5 inch tall, he says, — first latched onto a piece of grass, but then got ahold of the Q-tip. “If you look at the picture, there are actually some white blobs in the background. And those white blobs are actually plastic bags,” Hofman says. “There was a lot of trash. It was actually disgusting. The water started to smell.”

“There was a lot of trash. It was actually disgusting. The water started to smell.”

Taking the photo, with his Sony a7R II in Nauticam housing, was a moment of serendipity: Hofman had the wrong lens with him — a 16 to 35 millimeter wide angle lens. The seahorse was so tiny that a macro lens would have been better. But as the tide was moving around, and the seahorse was bouncing, the wide angle lens actually came as an advantage. It allowed Hofman to more easily frame the seahorse in the picture. “I never would have been able to get this thing framed with a macro lens,” he says.

The photo has gotten so much attention because it attracts and repulses people at the same time, Hofman says. The seahorse is cute, but it’s latching onto a Q-tip that reminds us of our footprint on the planet. The 33-year-old says he submitted the photo to the competition because he wanted “to get the biggest audience possible.” Winners will be announced next month, but he doesn’t care whether the photo wins. He’s not going to submit it to other competitions. “It’s accomplished what I wanted to do,” Hofman says. “I don’t care about the accolades.”

As a nature photographer, Hofman almost always shoots wildlife or under water. Lately, his work has become more conservation themed, he says. “I’ve been seeing more changes as I travel further and further,” Hofman says. “And I realize that the message needs to get out to the people who don’t have a chance to go there. I have to be their representative.”