Photojournalist Brian Skerry’s story on harp seals was one of his first cover stories focused on environmental issues for National Geographic magazine, published in 2004. During Thursday’s morning lecture in the Amphitheater, he took the audience through his personal journey as a photographer.

Skerry shared two photos from when he worked on the harp seal story. One was of a hunter dragging a seal carcass to land. In another, a seal five or six days old had fallen through thin ice, and its mother was frantically pushing it up for air. Though the seal survived, many others do not.

The story inspired Skerry to work on more stories focused on environmental issues in the ocean, he said. He has explored many places around the world to photograph a variety of marine wildlife.