Pacific suite: from ghost shrimp to gray whales, salmon to ancient forests, Clayoquot Sound yields a symphony of life.

Off the west coast of British Columbia's Vancouver Island, Bob Van Pelt tramped ahead across a smaller isle named Meares. We were in woods as old, quiet, green, and wet as a forest can be. Even the air felt soaked. It was hard to tell how much of the moisture came from the chilly rain, how much was fog, and how much was steam rising off the burly figure of a bearded Van Pelt, also known as Big Tree Bob. "I'm hot," he said with a shrug. "Big trees energize me."

When we reached a giant that the locals call Big Mother, Van Pelt, a researcher from the ...