To see this eerie exhibition, you’d need an oxygen tank and a pair of flippers. Photographer Andreas Franke installed a gallery more than a quarter mile below sea level. He displayed his photos on a sunken military ship off the coast of Key West, Florida. Plastic Ocean Project, above, features 17 portraits that depict subjects submerged in water surrounded by masses of plastic waste.

Franke hopes his exhibition will be a call to action against plastic pollution. “We’re destroying our oceans and [sea] creatures,” he says. “Everyone must do their part to save them. If we don’t, we [also] destroy ourselves.”