Harbor Seal Habitat and Sea Level Rise in the San Francisco Bay

Three harbor seals resting on rocky islets rising above the water during a low tide.
Harbor seals rest on exposed rocks in Point Bonita Cove, just outside of the San Francisco Bay.

NPS / Jessica Weinberg McClosky

December 2018 - Harbor seals are year-round residents of San Francisco Bay Area waters. But they don't just stay in the water. They also need safe places to come ashore to rest, shed their fur, and raise their young. They “haul out” in several coves, lagoons, and estuaries along the coast, and at sites within the San Francisco Bay. The rocks jutting out around Alcatraz Island, and larger islets like the Castro Rocks, are typical examples of desirable harbor seal habitat in the bay. What will happen to these sites as sea level rise reshapes the bay’s shoreline, including its exposed rocks and islands? An article in the December issue of Estuary News tackles this question with help from National Park Service ecologist Sarah Allen. Check out the full article, “Hauling Out on Higher Ground,” to learn more.

Alcatraz Island, Golden Gate National Recreation Area

Last updated: January 18, 2024