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Gulf of the Farallones

From the Beach to the Deep Sea: Exploring Ecosystems of the Gulf of the Farallones

By Sara Denka

Watch this amazing virtual 'fly-through' of deep-sea areas within the Gulf of the Farallones National Marine Sanctuary, then dive deeper into the sanctuary's diverse ecosystems with our in-depth guide below!

Thousands of years ago, before humans settled around San Francisco Bay, geologic forces were at work creating dramatic coastal mountains and deep sea floor ridges off the central California coast. Over time, these diverse habitats came to host an astounding array of animals and plants. Located just west of the Golden Gate Bridge, Gulf of the Farallones National Marine Sanctuary protects nearly 1,300 square miles of ocean. Join us on a journey through the diverse ecosystems of the sanctuary, from the sunny and sandy beaches to the dark depths of the deep sea!

A Hidden World Beneath the Sand

photo of stinson beach

An aerial view of Stinson Beach. Photo: NOAA

Abundant sunlight, oxygen and nutrients create ideal conditions for life along the shores of Gulf of the Farallones National Marine Sanctuary. Small pockets of sandy beach habitat, like Stinson and Muir beaches, are home to tiny organisms living on food brought to shore by the waves. Sand crabs and Pismo clams burrow deep in the sand, using special filters to strain microscopic plankton from the water, and sand fleas can be found dancing on the blades of giant kelp that wash ashore. The sanctuary's beaches serve as nurseries and breeding grounds for seals and sea lions, and 20 percent of California's harbor seals breed here in the spring.

Estuaries: The Land-Sea Interface

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The majestic Bolinas Lagoon on a foggy day. Photo: David Herlocker/Marin County Parks

Estuaries form where fresh water from the land drains into the sea. Gulf of the Farallones National Marine Sanctuary protects four major estuaries: Estero de San Antonio, Estero Americano, Tomales Bay and Bolinas Lagoon. Because of the high influx of nutrients, the estuaries provide another important nursery for marine life. Juvenile fish can be found taking shelter in eelgrass beds along the bottom of the estuaries, and thousands of shorebirds migrate to the estuaries in the winter to feed on the abundant fish and invertebrates living in the eelgrass.

Surviving the Force of the Waves

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The tough shell of a mossy chiton protects the invertebrate from the pounding waves. Photo from NOAA Encyclopedia of the Sanctuaries Website.

Marine invertebrates cling to the rocky shores that line the coastal zone of the sanctuary. Shore crabs hide from predators in small and dark crevices, while limpets, chitons and snails glue themselves to the rocks, their tough shells protecting them from the pounding surf. A low tide also exposes colorful anemones, urchins, and starfish in the tide pools formed amongst the rocks.

Wild Blue Ocean

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Humpback whales lunge-feed on small schooling fish and krill in sanctuary waters. Photo: Cornelia Oedekoven/NOAA

The open ocean is the dominant habitat of Gulf of the Farallones National Marine Sanctuary. Here, cold, nutrient-rich waters from the deep ocean are carried to the surface in a seasonal phenomenon known as "upwelling." This area is only one of five coastal upwelling zones in the world, and the copious zooplankton and krill found here are a key food source for commercial fish as well as ocean giants like gray whales, humpback whales and blue whales. The Farallon Islands are also home to one of the highest concentrations of great white sharks in the world, which gather seasonally in this hotspot of marine life to feed.

Into the Abyss

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A rosy rockfish rests in the cover of black coral, a species recently discovered to live in the sanctuary. Photo: NOAA

On the seaward edge of the sanctuary lies the Farallon Escarpment, where the seafloor drops as deep as 2,000 meters. Life here is both long and slow. Because very little light reaches these depths, food is scarce and organisms must move and metabolize slowly to conserve energy. Living at this speed allows these deep-sea creatures to live extraordinarily long lives. In fact, some bottom-dwelling rockfish can live for up to 200 years! Deep-sea invertebrates like anemones, corals, urchins, and sponges reside in the ridges of the escarpment. Cochrane Bank and Rittenburg Bank, both located west of the escarpment, host similar bottom-dwelling species. These banks are covered in a rich carpet of sponges and corals that provide shelter for fish.

Conserving the Sanctuary's Connected

Students participating in the Long-term Monitoring Program and Experiential Training for Students, or

Students participating in the Long-term Monitoring Program and Experiential Training for Students, or "LiMPETS," measure the health of a sandy beach habitat. Photo: NOAA GFNMS

Gulf of the Farallones National Marine Sanctuary was designated in 1981 to protect all of these magnificent ecosystems from human threats. However, impacts such as marine debris, ocean acidification, invasive species, and overfishing still threaten the health of this extraordinary place. Through extensive monitoring efforts, NOAA works to understand the dynamics of this complex network of habitats in an effort to better protect this ocean area that is truly unique in the world.

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Revised September 12, 2023 by Sanctuaries Web Team | Contact Us | Web Site Owner: National Ocean Service
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