Q&A With Sylvia Earle

The ocean conservationist on hope, and why she keeps diving

- SIMMONE SHAH

MARINE BIOLOGIST SYLVIA EARLE could easily rest on her laurels. In a career that began in the 1950s, she has become a pioneer in ocean exploration and conservation. She holds the record for the deepest walk under the sea and was the first female chief scientist at the U.S. National Oceanic and Atmospheric Administration. But on the cusp of her 90th birthday this August, she has no plans to slow down—and believes that the problems currently facing our oceans have never been more urgent. Her most recent venture, Mission Blue, aims to create a worldwide network of marine protected areas known as Hope Spots. This now includes the Chesapeake Bay. TIME spoke to Earle in May after a dive she made in the U.S.'s largest estuary.

You have been involved in ocean-conservation work for decades. What changes have you noticed since you first started this work?