Bay Area

The U.S. Navy knew as far back as 1993 that the tap water at its former shipyard in San Francisco contained dangerous amounts of lead, but didn’t tell local officials, visitors or people who worked there, including hundreds of police employees stationed at the site since 1997.

Researchers are using a rover to explore the depths of the ocean off Marin’s coast, looking for corals, sponges and other life forms that have adapted to the lightless environment and crushing pressures at the bottom of the sea.

A Sausalito marine biologist who has been named a National Geographic Explorer is using 3-D modeling, virtual reality and other frontier technologies to inspire people to protect the world’s oceans. Erika Woolsey, a Marin Academy graduate, has also helped found the Hydrous, a nonprofit based in Sausalito, devoted to ocean education.

Someone had a water balloon fight on Ocean Beach on a recent Saturday, just under the sand dunes across from Lincoln Way. Someone else peeled the wrapper off their new pack of cigarettes and lit up. And at some point in the past few months, someone enjoyed a coffee in a Styrofoam cup, probably on a damp, foggy morning like this one.

When Spreck Rosekrans visits Hetch Hetchy — the valley in Yosemite National Park that San Francisco turned into a reservoir nearly a century ago — he looks beyond what is. Instead, he envisions what once was and could be again.“ I imagine a meadow, dotted with oak, pine, and fir trees, and with the Tuolumne River meandering through it,” said Rosekrans, executive director of Restore Hetch Hetchy, a Berkeley-based nonprofit.