Mike Bear had just slipped underwater, offshore near San Diego, and was floating among the long fronds of a kelp forest when a long shadow passed between him and his diving partner. Gliding by, nearly within arm’s reach, was the sleek bulk of a sevengill shark, which Bear estimated at about nine feet long.
“To say we were startled would be an understatement,” Bear, a lifelong diver, says. The encounter, not uncommon among sevengill sharks, which inhabit the Pacific coast of the United States, left a lasting impression on Bear. It spurred him to co-found Ocean Sanctuaries, a non-profit organization that helps divers and ocean enthusiasts track sharks and other sea creatures.
The organization operates multiple programs that allow and encourage divers to submit images of sharks seen on dives to a database scientists use to learn about shark habitats and behavior. Understanding sharks helps us protect and conserve the species and their ocean ecosystems. Scientists depend on real-life observations of sharks to learn about their lives, but the oceans are vast, and it’s not possible to monitor much of them. But the millions of amateur divers exploring waters around the world function as an extended network of observers, vastly expanding the amount of data that can be collected.