San Francisco Bay, California
   HOME

TheInfoList



OR:

San Francisco Bay (
Chochenyo The Chochenyo (also called Chocheño, Chocenyo) are one of the divisions of the Indigenous Ohlone (Costanoan) people of Northern California. The Chochenyo reside on the east side of the San Francisco Bay (the East Bay), primarily in what is no ...
: 'ommu) is a large tidal
estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...
in the
U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...
state of
California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
, and gives its name to the
San Francisco Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a List of regions of California, region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose, California, S ...
. It is dominated by the cities of
San Francisco San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...
, San Jose, and
Oakland Oakland is a city in the East Bay region of the San Francisco Bay Area in the U.S. state of California. It is the county seat and most populous city in Alameda County, with a population of 440,646 in 2020. A major West Coast port, Oakland is ...
. The San Francisco Bay drains water from approximately 40 percent of California. Water from the
Sacramento Sacramento ( or ; ; ) is the capital city of the U.S. state of California and the seat of Sacramento County. Located at the confluence of the Sacramento and American Rivers in Northern California's Sacramento Valley, Sacramento's 2020 p ...
and San Joaquin rivers, and from the
Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...
mountains, flow into
Suisun Bay Suisun Bay ( ; Wintun for "where the west wind blows") is a shallow tidal estuary (a northeastern extension of the San Francisco Bay) in Northern California. It lies at the confluence of the Sacramento River and San Joaquin River, forming the e ...
, which then travels through the
Carquinez Strait The Carquinez Strait (; Spanish: ''Estrecho de Carquinez'') is a narrow tidal strait located in the Bay Area of Northern California, United States. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain int ...
to meet with the
Napa River The Napa River is a river approximately long in the U.S. state of California. It drains a famous wine-growing region called the Napa Valley, in the mountains north of the San Francisco Bay. Milliken Creek and Mt. Veeder watersheds are a f ...
at the entrance to
San Pablo Bay San Pablo Bay is a tidal estuary that forms the northern extension of the San Francisco Bay in the East Bay and North Bay regions of the San Francisco Bay Area in northern California. Most of the Bay is shallow; however, there is a deep wate ...
, which connects at its south end to San Francisco Bay. It then connects to the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
via the
Golden Gate The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by ...
strait. However, this entire group of interconnected bays is often called the ''San Francisco Bay''. The bay was designated a
Ramsar Wetland of International Importance Ramsar may refer to: * Places so named: ** Ramsar, Mazandaran, city in Iran ** Ramsar, Rajasthan, village in India * Eponyms of the Iranian city: ** Ramsar Convention The Ramsar Convention on Wetlands of International Importance Especially ...
on February 2, 2013, and the
Port of Oakland The Port of Oakland is the port authority for the city of Oakland, California, United States. Its primary responsibilities are the operation of the Oakland Seaport and the Oakland International Airport. It also operates a commercial real est ...
on the bay is one of the busiest cargo ports on the west coast.


Geography

The bay covers somewhere between , depending on which sub-bays (such as San Pablo Bay), estuaries,
wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
s, and so on are included in the measurement. The main part of the bay measures wide east-to-west and somewhere between 1 and 2 north-to-south. San Francisco Bay is the second-largest estuary on the Pacific coast of the Americas, following the
Salish Sea The Salish Sea ( ) is a List of seas on Earth #Terminology, marginal sea of the Pacific Ocean located in the Provinces and territories of Canada, Canadian province of British Columbia and the States of the United States , U.S. state of Washingto ...
in Washington State and British Columbia, Canada. The bay was navigable as far south as San Jose until the 1850s, when
hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...
released massive amounts of sediment from the rivers that settled in those parts of the bay that had little or no current. Later, wetlands and inlets were deliberately filled in, reducing the bay's size since the mid-19th century by as much as one third. Recently, large areas of wetlands have been restored, further confusing the issue of the bay's size. Despite its value as a waterway and
harbor A harbor (American English), or harbour (Commonwealth English; see spelling differences), is a sheltered body of water where ships, boats, and barges can be moored. The term ''harbor'' is often used interchangeably with ''port'', which is ...
, many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space. As a result, soil excavated for building projects or
dredged Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing dams ...
from channels was often dumped onto the wetlands and other parts of the bay as landfill. From the mid-19th century through the late 20th century, more than a third of the original bay was filled and often built on. The deep, damp soil in these areas is subject to
soil liquefaction Soil liquefaction occurs when a cohesionless saturated or partially saturated soil substantially loses Shear strength (soil), strength and stiffness in response to an applied Shear stress, stress such as shaking during an earthquake or other s ...
during earthquakes, and most of the major damage close to the bay in the
Loma Prieta earthquake On October 17, 1989, at 5:04 p.m. PST, the Loma Prieta earthquake occurred at the Central Coast of California. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately 10 mi (16 km) ...
of 1989 occurred to structures on these areas. The Marina District of San Francisco, hard hit by the 1989 earthquake, was built on fill that had been placed there for the Panama-Pacific International Exposition, although liquefaction did not occur on a large scale. In the 1990s,
San Francisco International Airport San Francisco International Airport is the primary international airport for the San Francisco Bay Area in the U.S. state of California. Owned and operated by the City and County of San Francisco, the airport has a San Francisco mailing ...
proposed filling in hundreds more acres to extend its overcrowded international
runway In aviation, a runway is an elongated, rectangular surface designed for the landing and takeoff of an aircraft. Runways may be a human-made surface (often asphalt concrete, asphalt, concrete, or a mixture of both) or a natural surface (sod, ...
s in exchange for purchasing other parts of the bay and converting them back to wetlands. The idea was, and remains, controversial. (''For further details, see the " Bay fill and depth profile" section.'') There are five large islands in San Francisco Bay.
Alameda An alameda is a street or path lined with trees () and may refer to: Places Canada * Alameda, Saskatchewan, town in Saskatchewan ** Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan Chile * Alameda (Santi ...
, the largest island, was created when a shipping lane was cut to form the
Port of Oakland The Port of Oakland is the port authority for the city of Oakland, California, United States. Its primary responsibilities are the operation of the Oakland Seaport and the Oakland International Airport. It also operates a commercial real est ...
in 1901. It is now a suburban community. Angel Island was known as "
Ellis Island Ellis Island is an island in New York Harbor, within the U.S. states of New Jersey and New York (state), New York. Owned by the U.S. government, Ellis Island was once the busiest immigrant inspection and processing station in the United State ...
West" because it served as the entry point for immigrants from East Asia. It is now a state park accessible by ferry. Mountainous
Yerba Buena Island Yerba Buena Island ( Spanish: ''Isla Yerba Buena'') sits in San Francisco Bay within the borders of the City and County of San Francisco. The Yerba Buena Tunnel runs through its center and connects the western and eastern spans of the San Fran ...
is pierced by a tunnel linking the east and west spans of the
San Francisco–Oakland Bay Bridge The San Francisco–Oakland Bay Bridge, commonly referred to as the Bay Bridge, is a complex of bridges spanning San Francisco Bay in California. As part of Interstate 80 in California, Interstate 80 and the direct road between San Francisco an ...
. Attached to the north is the artificial and flat
Treasure Island ''Treasure Island'' (originally titled ''The Sea Cook: A Story for Boys''Hammond, J. R. 1984. "Treasure Island." In ''A Robert Louis Stevenson Companion'', Palgrave Macmillan Literary Companions. London: Palgrave Macmillan. .) is an adventure a ...
, site of the 1939
Golden Gate International Exposition The Golden Gate International Exposition (GGIE) was a World's Fair held at Treasure Island in San Francisco, California, U.S. The exposition operated from February 18, 1939, through October 29, 1939, and from May 25, 1940, through September 29, ...
. From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the bay is
Alcatraz Alcatraz Island () is a small island about 1.25 miles offshore from San Francisco in San Francisco Bay, California, near the Golden Gate Strait. The island was developed in the mid-19th century with facilities for a lighthouse, a military fo ...
, the site of the famous federal penitentiary. The federal prison on
Alcatraz Island Alcatraz Island () is a small island about 1.25 miles offshore from San Francisco in San Francisco Bay, California, near the Golden Gate, Golden Gate Strait. The island was developed in the mid-19th century with facilities for a Alcatraz Isla ...
no longer functions, but the complex is a popular tourist site. Despite its name,
Mare Island Mare Island (Spanish language, Spanish: ''Isla de la Yegua'') is a peninsula in the United States in the city of Vallejo, California, about northeast of San Francisco. The Napa River forms its eastern side as it enters the Carquinez Strait junc ...
in the northern part of the bay is a peninsula rather than an island.


Geology

San Francisco Bay is thought to represent a down-warping of the Earth's crust between the
San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...
to the west and the
Hayward Fault The Hayward Fault Zone is a right-lateral strike-slip geologic fault zone capable of generating destructive earthquakes. The fault was first named in the Lawson Report of the 1906 San Francisco Earthquake in recognition of its involvement in the ...
to the east, though the precise nature of this remains under study. About 560,000 years ago, a
tectonic Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...
shift caused the large inland
Lake Corcoran Lake Corcoran (also known as Lake Clyde, after Clyde Wahrhaftig, an American geologist) was an ancient lake that covered the Central Valley of California. The lake existed in the valleys of the Sacramento River and the San Joaquin River, at l ...
to spill out the central valley and through the
Carquinez Strait The Carquinez Strait (; Spanish: ''Estrecho de Carquinez'') is a narrow tidal strait located in the Bay Area of Northern California, United States. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain int ...
, carving out sediment and forming canyons in what is now the northern part of the San Francisco Bay and Golden Gate strait. San Francisco Bay has been filled and emptied of sea water many times during the Pleistocene in accordance with sea level changes caused by glacial advances and retreats. During the
Wisconsin Glaciation The Wisconsin glaciation, also called the Wisconsin glacial episode, was the most recent glacial period of the North American ice sheet complex, peaking more than 20,000 years ago. This advance included the Cordilleran Ice Sheet, which nucleated ...
, between 15,000 and about 10,000 years ago, the basin which is now filled by the San Francisco Bay was a large river valley with small hills, channeling the
Sacramento River The Sacramento River () is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for before reaching the Sacramento–San Joaquin River D ...
through the Golden Gate Strait into the ocean. When the great ice sheets began to melt, around 11,000 years ago, the sea level started to rise rapidly, by about 1 inch per year. Melting glaciers in the Sierra Nevada washed huge amounts of sediment down the Sacramento and San Joaquin rivers, which accumulated on the shores of the bay, forming huge mudflats and marshes that supported local wildlife. By 5000 BC the sea level rose , filling the valley with water from the Pacific. The
Farallon Islands The Farallon Islands ( ), or Farallones (), are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, United States. The islands are also sometimes referred to by mariners as the Devil's ...
are what used to be hills along the old coastline, and Potato Patch Shoal is an area of sand dunes now covered by the ocean.


History

The indigenous inhabitants of the San Francisco Bay are
Ohlone The Ohlone ( ), formerly known as Costanoans (from Spanish meaning 'coast dweller'), are a Native Americans in the United States, Native American people of the Northern California coast. When Spanish explorers and missionaries arrived in the l ...
. The first European to see San Francisco Bay is likely
N. de Morena N. de Morena or N. de Morera, name given to him by his contemporary Fray Juan de Torquemada and by most authors, was a European ship pilot in the 1577–1580 expedition of Sir Francis Drake. In ill health, he was reportedly left at New Albion in 15 ...
who was left at
New Albion New Albion, also known as ''Nova Albion'' (in reference to Albion, an archaic name for Great Britain), was the name of the continental area north of Mexico claimed by Sir Francis Drake for Kingdom of England, England when he landed on the Nort ...
at
Drakes Bay Drakes Bay ( Coast Miwok: ''Tamál-Húye'') is a bay along the Point Reyes National Seashore on the coast of northern California in the United States, approximately northwest of San Francisco at approximately 38 degrees north latitude. The ...
in
Marin County, California Marin County ( ) is a County (United States), county located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 United States census, 2020 census, the population was 262,231. Its county seat a ...
, by
Sir Francis Drake Sir Francis Drake ( 1540 – 28 January 1596) was an English Exploration, explorer and privateer best known for making the Francis Drake's circumnavigation, second circumnavigation of the world in a single expedition between 1577 and 1580 (bein ...
in 1579 and then walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769, when Spanish explorer
Gaspar de Portolá Captain Gaspar de Portolá y Rovira (January 1, 1716 – October 10, 1786) was a Spanish Army officer and colonial administrator who served as the first List of governors of California before 1850, governor of the Californias from 1767 to 1770 ...
, unable to find the Port of Monterey, continued north close to what is now Pacifica and reached the summit of the
Sweeney Ridge Sweeney Ridge, is a hilly hiking area of ridges and ravines between San Bruno and Pacifica, California, about a 25-minute drive south from San Francisco. The ridge's 1,200-foot-high summit, covered with coastal scrub and grassland, slopes down t ...
, now marked as the place where he first sighted San Francisco Bay. Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called
Drakes Bay Drakes Bay ( Coast Miwok: ''Tamál-Húye'') is a bay along the Point Reyes National Seashore on the coast of northern California in the United States, approximately northwest of San Francisco at approximately 38 degrees north latitude. The ...
. At the time, Drakes Bay went by the name ''Bahia de San Francisco'' and thus both bodies of water became associated with the name. Eventually, the larger, more important body of water fully appropriated the name ''San Francisco Bay''. The first European to enter the bay is believed to have been the Spanish explorer
Juan de Ayala Juan Manuel de Ayala y Aranza (28 December 1745 – 30 December 1797) was a Spanish Navy officer who played a significant role in the European exploration of California, as he and the crew of his ship ''San Carlos'' were the first Europeans kn ...
, who passed through the
Golden Gate The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by ...
on August 5, 1775, in his ship the ''San Carlos'' and moored in a bay of Angel Island now known as Ayala Cove. Ayala continued to explore the
San Francisco Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a List of regions of California, region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose, California, S ...
and the expedition's cartographer, José de Cañizares, gathered the information necessary to produce the first map of the area. A number of place names survive (anglicized) from that first map, including
Point Reyes Point Reyes ( , meaning 'Cape of the Kings') is a prominent landform and popular tourist destination on the Pacific coast of Marin County in Northern California. It is approximately west-northwest of San Francisco. The term is often applied ...
, Angel Island,
Farallon Islands The Farallon Islands ( ), or Farallones (), are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, United States. The islands are also sometimes referred to by mariners as the Devil's ...
, and
Alcatraz Island Alcatraz Island () is a small island about 1.25 miles offshore from San Francisco in San Francisco Bay, California, near the Golden Gate, Golden Gate Strait. The island was developed in the mid-19th century with facilities for a Alcatraz Isla ...
.
Alaskan Native Alaska Natives (also known as Native Alaskans, Alaskan Indians, or Indigenous Alaskans) are the Indigenous peoples of Alaska that encompass a diverse arena of cultural and linguistic groups, including the Iñupiat, Yupik, Aleut, Eyak, Tlin ...
sea otter hunters using
Aleutian kayak The baidarka or Aleutian kayak (Aleut: iqyax) is a watercraft consisting of soft skin (artificial or natural) over a flexible space frame. Without primarily vertical flex, it is not an ''iqyax''. Its initial design was created by the Aleut peo ...
s and working for the
Russian–American Company The Russian-American Company Under the High Patronage of His Imperial Majesty was a state-sponsored chartered company formed largely on the basis of the United American Company. Emperor Paul I of Russia chartered the company in the Ukase of 17 ...
entered San Francisco Bay in 1807 and again over 1810–1811. Led by the Russian
Timofei Nikitich Tarakanov Timofei Nikitich Tarakanov ( 1774after 1834), also written Timofey Tarakanov, was born into serfdom near Kursk, Russia. His owner, Nikanor Ivanovich Pereverzev, sold him to the Russian-American Company (RAC) shortly after the company was created in ...
, these hunting raids probably wiped out sea otters in the bay. Thousands of sea otter skins were taken to Sitka, then
Guangzhou Guangzhou, Chinese postal romanization, previously romanized as Canton or Kwangchow, is the Capital city, capital and largest city of Guangdong Provinces of China, province in South China, southern China. Located on the Pearl River about nor ...
(Canton), China, where they commanded a high price. The United States seized the region from Mexico during the
Mexican–American War The Mexican–American War (Spanish language, Spanish: ''guerra de Estados Unidos-México, guerra mexicano-estadounidense''), also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico, ...
(1846–1848). On February 2, 1848, the Mexican province of
Alta California Alta California (, ), also known as Nueva California () among other names, was a province of New Spain formally established in 1804. Along with the Baja California peninsula, it had previously comprised the province of , but was made a separat ...
was annexed to the United States with the signing of the
Treaty of Guadalupe Hidalgo The Treaty of Guadalupe Hidalgo officially ended the Mexican–American War (1846–1848). It was signed on 2 February 1848 in the town of Villa de Guadalupe, Mexico City, Guadalupe Hidalgo. After the defeat of its army and the fall of the cap ...
. A year and a half later, California requested to join the United States on December 3, 1849, and was accepted as the 31st State of the Union on September 9, 1850. In 1921, a tablet was dedicated by a group of men in downtown San Francisco, marking the site of the original shoreline. The tablet reads: "This tablet marks the shore line of San Francisco Bay at the time of the discovery of gold in California, January 24, 1848. Map reproduced above delineates old shore line. Placed by the Historic Landmarks committee,
Native Sons of the Golden West The Native Sons of the Golden West (NSGW) is a fraternity, fraternal service organization founded in the U.S. state of California in 1875, dedicated to historic preservation and documentation of the state's historic structures and places, the pla ...
, 1921." The bay became the center of American settlement and commerce in the Far West through most of the remainder of the 19th century. During the
California Gold Rush The California gold rush (1848–1855) began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California from the rest of the U ...
(1848–1855), San Francisco Bay suddenly became one of the world's great seaports, dominating shipping in the American West until the last years of the 19th century. The bay's regional importance increased further when the
first transcontinental railroad America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the "Overland Route (Union Pacific Railroad), Overland Route") was a continuous railroad line built between 1863 and 1869 that connected the exis ...
was connected to its western terminus at
Alameda An alameda is a street or path lined with trees () and may refer to: Places Canada * Alameda, Saskatchewan, town in Saskatchewan ** Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan Chile * Alameda (Santi ...
on September 6, 1869. The terminus was switched to the
Oakland Long Wharf The Oakland Long Wharf was an 11,000-foot railroad wharf and ferry pier along the east shore of San Francisco Bay located at the foot of Seventh Street in West Oakland, Oakland, California, West Oakland. The Oakland Long Wharf was built, beginn ...
two months later on November 8, 1869. In 1910, the
Southern Pacific The Southern Pacific (or Espee from the railroad initials) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names ...
railroad company built the
Dumbarton Rail Bridge The Dumbarton Rail Bridge lies just to the south of the Dumbarton road bridge. Built in 1910, the rail bridge was the first structure to span San Francisco Bay, shortening the rail route between Oakland and San Francisco by . The last freight ...
, the first bridge crossing San Francisco Bay. The first automobile crossing was the Dumbarton Bridge, completed in January 1927. More crossings were later constructed – the
Carquinez Bridge The Carquinez Bridge is a pair of parallel bridges spanning the Carquinez Strait at the northeastern end of San Francisco Bay. They form the part of Interstate 80 between Crockett and Vallejo, California, United States. The name Carquinez B ...
in May 1927, the
San Francisco–Oakland Bay Bridge The San Francisco–Oakland Bay Bridge, commonly referred to as the Bay Bridge, is a complex of bridges spanning San Francisco Bay in California. As part of Interstate 80 in California, Interstate 80 and the direct road between San Francisco an ...
in 1936, the
Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...
in 1937, the Richmond–San Rafael Bridge in 1956, and the
San Mateo–Hayward Bridge The San Mateo–Hayward Bridge (commonly called the San Mateo Bridge) is a bridge crossing the American state of California's San Francisco Bay, linking the San Francisco Peninsula with the East Bay. The bridge's western end is in Foster Cit ...
in 1967. During the 20th century, the bay was subject to the 1940s
Reber Plan The Reber Plan was a late 1940s plan to fill in parts of the San Francisco Bay. It was designed and advocated by John Reber—an actor and theatrical producer. San Francisco Bay Project Under the plan, which was also known as the San Francisco ...
, which would have filled in parts of the bay in order to increase industrial activity along the waterfront. In 1959, the
United States Army Corps of Engineers The United States Army Corps of Engineers (USACE) is the military engineering branch of the United States Army. A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment, military construction, and civil wo ...
released a report stating that if current infill trends continued, the bay would be as big as a shipping channel by 2020. This news led to the creation of the
Save the Bay Save The Bay is a nonprofit organization dedicated to preserving San Francisco Bay and related estuarine habitat areas. It was founded by Catherine Kerr, Sylvia McLaughlin, and Esther Gulick in 1961. The organization aims to protect the ...
movement in 1960, which mobilized to stop the infill of wetlands as well as the bay itself, which had shrunk to two-thirds of its size in the century before 1961. On September 17, 1965, the
California State Legislature The California State Legislature is the bicameral state legislature of the U.S. state of California, consisting of the California State Assembly (lower house with 80 members) and the California State Senate (upper house with 40 members). ...
enacted the McAteer-Petris Act, which created the
San Francisco Bay Conservation and Development Commission The San Francisco Bay Conservation and Development Commission (BCDC) is a California state commission dedicated to the protection, enhancement and responsible use of the San Francisco Bay. It holds jurisdiction over almost the entirety of the Ba ...
. Since then, the Commission has strictly regulated bay fill.
Foster City Foster City is a master-planned city located in San Mateo County, California, United States. Foster City is sometimes considered to be part of Silicon Valley for its local industry and its proximity to Silicon Valley cities. There are many n ...
,
Redwood Shores Redwood Shores is a waterfront community in Redwood City, California, along the western shore of San Francisco Bay on the San Francisco Peninsula in San Mateo County, California, San Mateo County. Redwood Shores is the home of several major tech ...
, Paradise Cay, and Emeryville's western expansion were among the last developments along the bay shoreline before McAteer-Petris limited additional filling of the bay. The San Francisco Bay continues to support some of the densest industrial production and urban settlement in the United States. The
San Francisco Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a List of regions of California, region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose, California, S ...
is the American West's second-largest urban area, with approximately seven million residents.


Ecology

Despite its urban and industrial character, San Francisco Bay and the
Sacramento–San Joaquin River Delta The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Central California and Northern California Northern California (commonly shortened to NorCal) is a geocultural region that ...
remain perhaps California's most important ecological habitats. California's
Dungeness crab The Dungeness crab (''Metacarcinus magister'') makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, Califo ...
,
California halibut The California halibut or California flounder (''Paralichthys californicus'') is a large-tooth flounder native to the waters of the Pacific Coast of North America from the Quillayute River in Washington (U.S. state), Washington to Magdalena Bay ...
, and
Pacific salmon ''Oncorhynchus'', from Ancient Greek ὄγκος (''ónkos''), meaning "bend", and ῥύγχος (''rhúnkhos''), meaning "snout", is a genus of ray-finned fish in the subfamily Salmoninae of the family Salmonidae, native to coldwater tributarie ...
fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...
rely on the bay as a nursery. The few remaining
salt marsh A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. I ...
es now represent most of California's remaining salt marsh, supporting a number of endangered
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
and providing key
ecosystem services Ecosystem services are the various benefits that humans derive from Ecosystem, ecosystems. The interconnected Biotic_material, living and Abiotic, non-living components of the natural environment offer benefits such as pollination of crops, clean ...
such as filtering pollutants and
sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...
s from the rivers. San Francisco Bay is recognized for protection by the
California Bays and Estuaries Policy California () is a state in the Western United States that lies on the Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares an international border with the Mexican state of Baja California to the sout ...
, with oversight provided by the San Francisco Estuary Partnership.State Water Resources Control Board ''Water Quality Control Policy for the Enclosed Bays and Estuaries of California'' (1974) State of California Most famously, the bay is a key link in the
Pacific Flyway The Pacific Flyway is a major north-south flyway for migratory birds in the Americas, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading ...
. Millions of
waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which i ...
annually use the bay shallows as a refuge. Two
endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
of birds are found here: the
California least tern The California least tern (''Sternula antillarum browni'') is a subspecies of least tern that breeds primarily in bays of the Pacific Ocean within a very limited range of Southern California, in San Francisco Bay and in northern regions of Mexi ...
and the Ridgway's Rail. Exposed
bay mud Bay mud consists of thick deposits of soft, unconsolidated silty clay, which is saturated with water; these soil layers are situated at the bottom of certain estuary, estuaries, which are normally in temperate regions that have experienced cyclic ...
s provide important feeding areas for
shorebird 245px, A flock of Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflats in order to foraging, ...
s, but underlying layers of bay mud pose geological hazards for structures near many parts of the bay perimeter. San Francisco Bay provided the nation's first wildlife refuge, Oakland's artificial
Lake Merritt Lake Merritt is a lake located in a large tidal lagoon basin in the center of Oakland, California, just east of Downtown. It is named after Samuel Merritt, Oakland's mayor in 1867–1869, who had the lagoon dammed turning the varying tidal lag ...
, constructed in the 1860s, and America's first urban National Wildlife Refuge, the
Don Edwards San Francisco Bay National Wildlife Refuge Don Edwards San Francisco Bay National Wildlife Refuge (DESFBNWR) is a United States National Wildlife Refuge located in the southern part of San Francisco Bay, California. Its headquarters and visitor center are in the Baylands district of Fre ...
(SFBNWR) in 1972. The bay is also plagued by non-native species. Salt produced from San Francisco Bay is produced in
salt evaporation pond A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines. The salt pans are shallow and expansive, allowing sunlight to penetrate and reach the seawater. Natural salt pans are formed thr ...
s and is shipped throughout the Western United States to bakeries, canneries, fisheries, cheese makers and other food industries and used to de-ice winter highways, clean kidney dialysis machines, for animal nutrition, and in many industries. Many companies have produced salt in the bay, with the Leslie Salt Company the largest private land owner in the
Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose. The Association of Bay Area Governments ...
in the 1940s. Low-salinity salt ponds mirror the ecosystem of the bay, with fish and fish-eating birds in abundance. Mid-salinity ponds support dense populations of
brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp or ''Sea-Monkeys, sea monkeys''. It is the only genus in the Family (biology), family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to t ...
, which provide a rich food source for millions of shorebirds. Only salt-tolerant micro-algae survive in the high salinity ponds, and impart a deep red color to these ponds from the pigment within the algae protoplasm. The
salt marsh harvest mouse The salt-marsh harvest mouse (''Reithrodontomys raviventris''), also known as the red-bellied harvest mouse, is an endangered rodent endemic to the San Francisco Bay Area salt marshes in California. Taxonomy The two distinct subspecies are both ...
is an endangered species endemic to the wetlands of the San Francisco Bay with a high salt tolerance. It needs native
pickleweed Pickleweed is a common name used for two unrelated genera of flowering plants: *'' Batis'', family Bataceae *''Salicornia ''Salicornia'' is a genus of succulent, halophytic (salt tolerant) flowering plants in the family Amaranthaceae that grow i ...
, which is often displaced by invasive cordgrass, for its habitat. The seasonal range of water temperature in the bay is from January's to September's when measured at Fort Point, which is near the southern end of the
Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...
and at the entrance to San Francisco Bay. For the first time in 65 years, Pacific Harbor Porpoise (''Phocoena phocoena'') returned to the bay in 2009. Golden Gate Cetacean Research, a non-profit organization focused on research on
cetacean Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
s, has developed a photo-identification database enabling the scientists to identify specific porpoise individuals and is trying to ascertain whether a healthier bay has brought their return. Pacific harbor porpoise range from
Point Conception Point Conception (Chumashan languages, Chumash: ''Humqaq'') is a headland along the Gaviota Coast in southwestern Santa Barbara County, California, United States. It is the point where the Santa Barbara Channel meets the Pacific Ocean, and as ...
, California, to Alaska and across to the
Kamchatka Peninsula The Kamchatka Peninsula (, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific ...
and Japan. Recent genetic studies show that there is a local stock from San Francisco to the Russian River and that eastern Pacific coastal populations rarely migrate far, unlike western Atlantic Harbor porpoise. The
common bottlenose dolphin The common bottlenose dolphin or Atlantic bottlenose dolphin (''Tursiops truncatus'') is one of three species of bottlenose dolphin in the genus ''Tursiops''. The common bottlenose dolphin is a very familiar dolphin due to the wide exposure it re ...
(''Tursiops truncatus'') has been extending its current range northwards from the
Southern California Bight The Southern California Bight is a 692-kilometer-long (430 mi) stretch of curved coastline that runs along the West Coast of the United States and Mexico, from Point Conception in California to Punta Colonet in Baja California, plus the area of t ...
. The first coastal bottlenose dolphin in the Bay Area in recent times was spotted in 1983 off the
San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county (United States), county located in the U.S. state of California. As of the 2020 United States census, the population was 764,442. Redwood City, California, Redwood City is th ...
coast in 1983. In 2001, bottlenose dolphins were first spotted east of the Golden Gate Bridge and confirmed by photographic evidence in 2007. Zooarcheological remains of bottlenose dolphins indicated that bottlenose dolphins inhabited San Francisco Bay in prehistoric times until at least 700 years before present, and dolphin skulls dredged from the bay suggest occasional visitors in historic times.


Pollution

San Francisco Bay faces many of the same water quality issues as other urban waterways in industrialized countries, or downstream of intensive agriculture. According to state water quality regulators, San Francisco Bay waters do not meet water quality standards for the following pollutants: *
DDT Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
* Mercury *
Selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
*
Polychlorinated biphenyls Polychlorinated biphenyls (PCBs) are organochlorine compounds with the formula C12 H10−''x'' Cl''x''; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids f ...
(PCBs) *
Dioxin Dioxin may refer to a number of different substances. Most notably: * 1,2-Dioxin or 1,4-dioxin, two unsaturated heterocyclic 6-membered rings in which two carbon atoms have been replaced by oxygen atoms, which gives the molecular formula C4H4O2 ...
compounds *
Furan Furan is a Heterocyclic compound, heterocyclic organic compound, consisting of a five-membered aromatic Ring (chemistry), ring with four carbon Atom, atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as f ...
compounds * Trash *
Diazinon Diazinon (IUPAC name: ''O'',''O''-Diethyl ''O''- -methyl-6-(propan-2-yl)pyrimidin-2-ylphosphorothioate, INN - Dimpylate), a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company ...
*
Chlordane Chlordane, or chlordan, is an organochlorine compound that was used as a pesticide. It is a white solid. In the United States, chlordane was used for termite-treatment of approximately 30 million homes until it was banned in 1988. Chlordane was b ...
*
Dieldrin Dieldrin is an organochlorine compound originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the i ...


Mercury

Industrial, mining, and other uses of mercury have resulted in a widespread distribution in the bay, with uptake in the bay's
phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...
and contamination of its sportfish.


Oil spills

In January 1971, two
Standard Oil Standard Oil Company was a Trust (business), corporate trust in the petroleum industry that existed from 1882 to 1911. The origins of the trust lay in the operations of the Standard Oil of Ohio, Standard Oil Company (Ohio), which had been founde ...
tankers collided in the bay, creating an oil spill disaster, which spurred environmental protection of the bay. In November 2007, a ship named '' COSCO Busan'' collided with the
San Francisco–Oakland Bay Bridge The San Francisco–Oakland Bay Bridge, commonly referred to as the Bay Bridge, is a complex of bridges spanning San Francisco Bay in California. As part of Interstate 80 in California, Interstate 80 and the direct road between San Francisco an ...
and spilled over of
bunker fuel Heavy fuel oil (HFO) is a category of fuel oils of a tar-like consistency. Also known as bunker fuel, or residual fuel oil, HFO is the result or remnant from the distillation and cracking process of petroleum. For this reason, HFO contains sev ...
, creating the largest
oil spill An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to marine oil spills, where oil is released into th ...
in the region since 1996.


Nutrients

The bay also has some of the highest levels of dissolved inorganic nitrogen known from any coastal water body, mostly originating from treated wastewater from
Publicly owned treatment works A publicly owned treatment works (POTW) is a term used in the United States for a sewage treatment plant owned, and usually operated, by a government agency. In the U.S., POTWs are typically owned by local government agencies, and are usually desig ...
. In other bays, such nutrient levels would likely lead to
eutrophication Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the s ...
, but historically, the bay has had less
harmful algal blooms A harmful algal bloom (HAB), or excessive algae growth, sometimes called a red tide in marine environments, is an algal bloom that causes negative impacts to other organisms by production of natural algae-produced toxins, water deoxygenation, ...
than other water bodies with similar nutrient concentrations. Potential explanations have included the presence of intensive "top-down control" from grazing clams like '' Potamocorbula'', high sediment supply limiting light availability for the algae, and intensive tidal mixing. The occurrence of an unprecedented harmful algal bloom of ''
Heterosigma akashiwo ''Heterosigma akashiwo'' is a species of microscopic algae of the class Raphidophyceae. It is a swimming marine alga that episodically forms toxic surface aggregations known as harmful algal bloom. The species name ''akashiwo'' is from the Japan ...
'' in 2022, resulting in mass fish deaths and anoxia, suggests that the mechanisms of control on algal growth may be eroding.


PBDEs

The bay was once considered a hotspot for polybrominated diphenyl ether (
PBDE Polybrominated diphenyl ethers or PBDEs, are a class of organobromine compounds that are used as flame retardants. Like other brominated flame retardants, PBDEs have been used in a wide array of products, including building materials, electronic ...
) flame retardants used to make upholstered furniture and infant care items less flammable. PBDEs have been largely phased out and replaced with alternative phosphate flame retardants. A 2019
San Francisco Estuary Institute The San Francisco Estuary Institute (SFEI) is a nonprofit research institute focusing on the estuaries and ecosystems of San Francisco Bay and Northern California. SFEI was created in 1992 in order to coordinate integrated research and monitoring ...
(SFEI) study assayed a wide range of these newer flame retardant chemicals in Bay waters, bivalve
California mussel The California mussel (''Mytilus californianus'') is a large edible mussel, a Marine (ocean), marine bivalve mollusc, mollusk in the family Mytilidae. This species is native to the west coast of North America, occurring from northern Mexico to ...
s (''Mytilus californianus''), and
harbor seal The harbor (or harbour) seal (''Phoca vitulina''), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped (walruses, eared sea ...
s (''Phoca vitulina'') which haul out in Corkscrew Slough on
Bair Island Bair Island is a marsh area in Redwood City, California, covering , and includes three islands: Inner, Middle and Outer islands. Bair Island is part of the larger Don Edwards San Francisco Bay National Wildlife Refuge. It is surrounded by the ...
in
San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county (United States), county located in the U.S. state of California. As of the 2020 United States census, the population was 764,442. Redwood City, California, Redwood City is th ...
, with phosphate flame retardant contaminants such as
tris(1,3-dichloro-2-propyl)phosphate Tris(1,3-dichloroisopropyl)phosphate (TDCPP) is a chlorinated organophosphate. Organophosphate chemicals have a wide variety of applications and are used as flame retardants, pesticides, plasticizers, and nerve gases. TDCPP is structurally sim ...
(TDCPP) and
triphenyl phosphate Triphenyl phosphate (TPhP) is the chemical compound with the formula OP(OC6H5)3. It is the simplest aromatic organophosphate. This colourless solid is the ester (triester) of phosphoric acid and phenol. It is used as a plasticizer and a fire retar ...
(TPhP) found at levels comparable to thresholds for aquatic toxicity.


Emerging contaminants

Thousands of man-made chemicals are found in Bay water, sediment, and organisms. For many of these, there is little or no data on their impacts on the environment or human health, and they are not regulated by state or federal law. These are often referred to as "contaminants of emerging concern." The
San Francisco Estuary Institute The San Francisco Estuary Institute (SFEI) is a nonprofit research institute focusing on the estuaries and ecosystems of San Francisco Bay and Northern California. SFEI was created in 1992 in order to coordinate integrated research and monitoring ...
has studied these chemicals in the Bay since 2001. Scientists have identified the following most likely to have a negative impact on Bay wildlife: *
PFOS Perfluorooctanesulfonic acid (PFOS) (conjugate base perfluorooctanesulfonate) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group, and thus it is a perfluorosulfonic acid and a perfluoroalkyl su ...
*
fipronil Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole insecticide class. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor ( IRAC group 2B) and glutamate-g ...
*
nonylphenol Nonylphenols are a family of closely related organic compounds composed of phenol bearing a 9 carbon-tail. Nonylphenols can come in numerous structures, all of which may be considered alkylphenols. They are used in manufacturing antioxidants, l ...
s * nonylphenol ethoxylates


Bay fill and depth profile

San Francisco Bay's profile changed dramatically in the late 19th century and again with the initiation of dredging by the
US Army Corps of Engineers The United States Army Corps of Engineers (USACE) is the military engineering branch of the United States Army. A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment, military construction, and civil wor ...
in the 20th century. Before about 1860, most bay shores (with the exception of rocky shores, such as those in Carquinez Strait; along Marin shoreline; Point Richmond; Golden Gate area) contained extensive wetlands that graded nearly invisibly from freshwater wetlands to salt marsh and then tidal mudflat. A deep channel ran through the center of the bay, following the ancient drowned river valley. In the 1860s and continuing into the early 20th century, miners dumped staggering quantities of mud and gravel from
hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...
operations into the upper Sacramento and San Joaquin Rivers. GK Gilbert's estimates of debris total more than eight times the amount of rock and dirt moved during construction of the Panama Canal. This material flowed down the rivers, progressively eroding into finer and finer sediment, until it reached the bay system. Here some of it settled, eventually filling in Suisun Bay, San Pablo Bay, and San Francisco Bay, in decreasing order of severity. By the end of the 19th century, these "
slickens In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material th ...
" had filled in much of the shallow bay flats, raising the entire bay profile. New marshes were created in some areas. In the decades surrounding 1900, at the behest of local political officials and following Congressional orders, the U.S. Army Corps began dredging the Sacramento and San Joaquin Rivers and the deep channels of San Francisco Bay. This work has continued without interruption ever since. Some of the dredge spoils were initially dumped in the bay shallows (including helping to create
Treasure Island ''Treasure Island'' (originally titled ''The Sea Cook: A Story for Boys''Hammond, J. R. 1984. "Treasure Island." In ''A Robert Louis Stevenson Companion'', Palgrave Macmillan Literary Companions. London: Palgrave Macmillan. .) is an adventure a ...
on the former
shoal In oceanography, geomorphology, and Earth science, geoscience, a shoal is a natural submerged ridge, bank (geography), bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body ...
s to the north of
Yerba Buena Island Yerba Buena Island ( Spanish: ''Isla Yerba Buena'') sits in San Francisco Bay within the borders of the City and County of San Francisco. The Yerba Buena Tunnel runs through its center and connects the western and eastern spans of the San Fran ...
) and used to raise islands in the Sacramento-San Joaquin Delta. The net effect of dredging has been to maintain a narrow deep channel—deeper perhaps than the original bay channel—through a much shallower bay. At the same time, most of the marsh areas have been filled or blocked off from the bay by
dikes Dyke or dike may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), formations of magma or sediment that cut through and across the layering of adjacent rocks * Dike (mythology), ''Dikē'', the Greek goddess ...
. Large ships transiting the bay must follow deep underwater channels that are maintained by frequent dredging as the average depth of the bay is only as deep as a swimming pool—approximately . Between Hayward and San Mateo to San Jose it is . The deepest part of the bay is under and out of the Golden Gate Bridge, at . In the late 1990s, a 12-year harbor-deepening project for the
Port of Oakland The Port of Oakland is the port authority for the city of Oakland, California, United States. Its primary responsibilities are the operation of the Oakland Seaport and the Oakland International Airport. It also operates a commercial real est ...
began; it was largely completed by September 2009. Previously, the bay waters and harbor facilities only allowed for ships with a draft of , but
dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...
activities undertaken by the United States Army Corps of Engineers in partnership with the Port of Oakland succeeded in providing access for vessels with a draft. Four dredging companies were employed in the US$432 million project, with $244 million paid for with federal funds and $188 million supplied by the Port of Oakland. Some of mud from the dredging was deposited at the western edge of
Middle Harbor Shoreline Park Middle Harbor Shoreline Park (MHSP) is located on San Francisco Bay and the Oakland Seaport entrance channel, west of downtown Oakland, California. It is owned and operated by the Port of Oakland. The park entrance is at the intersection of 7th S ...
to become a shallow-water
wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
s habitat for marine and shore life. Further dredging followed in 2011, to maintain the navigation channel. This dredging enabled the arrival of the largest
container ship A container ship (also called boxship or spelled containership) is a cargo ship that carries all of its load in truck-size intermodal containers, in a technique called containerization. Container ships are a common means of commercial intermodal ...
ever to enter the San Francisco Bay, the ''
MSC Fabiola ''Madrid Express'' (originally ''MSC Fabiola'') is a container ship built for the Hamburg based Peter Döhle Schiffahrtsgesellschaft by Samsung Heavy Industries in South Korea. The ship was initially chartered by the Mediterranean Shipping Company ...
''. Bay
pilots An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators because they are ...
trained for the visit on a simulator at the
California Maritime Academy The California State University Maritime Academy (Cal Maritime or CSU Maritime Academy) is a public university in Vallejo, California, United States. It is part of the California State University system and the only maritime academy on the co ...
for over a year. The ship arrived drawing less than its full draft of because it held only three-quarters of a load after its stop in Long Beach.


Transportation

San Francisco Bay was traversed by watercraft before the arrival of Europeans. Indigenous peoples used canoes to fish and clam along the shoreline. Sailing ships enabled transportation between the bay and other parts of the world—and served as ferries and freighters within the bay and between the bay and inland ports, such as Sacramento and Stockton. These were gradually replaced by steam-powered vessels starting in the late 19th century. Several shipyards were established around the bay, augmented during wartime (e.g., the
Kaiser Shipyards The Kaiser Shipyards were seven major shipbuilding yards located on the West Coast of the United States, United States west coast during World War II. Kaiser ranked 20th among U.S. corporations in the value of wartime production contracts. The ...
,
Richmond Shipyards The four Richmond Shipyards, in the city of Richmond, California, United States, were run by Permanente Metals and part of the Kaiser Shipyards. In World War II, Richmond built more ships than any other shipyard, turning out as many as three ships ...
) near
Richmond Richmond most often refers to: * Richmond, British Columbia, a city in Canada * Richmond, California, a city in the United States * Richmond, London, a town in the London Borough of Richmond upon Thames, England * Richmond, North Yorkshire, a town ...
in 1940 for
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
for construction of mass-produced, assembly line
Liberty Liberty is the state of being free within society from oppressive restrictions imposed by authority on one's way of life, behavior, or political views. The concept of liberty can vary depending on perspective and context. In the Constitutional ...
and Victory cargo ships. San Francisco Bay is spanned by nine bridges, eight of which carry
car A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than cargo. There are around one billio ...
s. * The
Richmond–San Rafael Bridge The Richmond–San Rafael Bridge (officially renamed the John F. McCarthy Memorial Bridge in 1981) is the northernmost of the east–west crossings of California's San Francisco Bay, carrying Interstate 580 from Richmond on the east to San R ...
on Interstate 580 (I-580) connects Marin and Contra Costa counties. * The
Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...
on U.S. Route 101/ State Route 1 (US 101/SR 1) was the largest single span
suspension bridge A suspension bridge is a type of bridge in which the deck (bridge), deck is hung below suspension wire rope, cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridg ...
ever built at the time of its 1937 construction. It spans the
Golden Gate The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by ...
, the strait between San Francisco and Marin County, and is the only bridge in the area not owned by the State of California. * The
San Francisco–Oakland Bay Bridge The San Francisco–Oakland Bay Bridge, commonly referred to as the Bay Bridge, is a complex of bridges spanning San Francisco Bay in California. As part of Interstate 80 in California, Interstate 80 and the direct road between San Francisco an ...
on
I-80 Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one of the ori ...
connects Alameda and San Francisco counties. * The
San Mateo–Hayward Bridge The San Mateo–Hayward Bridge (commonly called the San Mateo Bridge) is a bridge crossing the American state of California's San Francisco Bay, linking the San Francisco Peninsula with the East Bay. The bridge's western end is in Foster Cit ...
on SR 92 connects Alameda and San Mateo counties. * The Dumbarton Bridge on SR 84 connects Alameda and San Mateo counties. * The
Carquinez Bridge The Carquinez Bridge is a pair of parallel bridges spanning the Carquinez Strait at the northeastern end of San Francisco Bay. They form the part of Interstate 80 between Crockett and Vallejo, California, United States. The name Carquinez B ...
(including the Alfred Zampa Memorial Bridge) on I-80 connects Contra Costa and Solano counties. * The
Benicia Bridge Benicia ( , ) is a city in Solano County, California, located on the north bank of the Carquinez Strait in the North Bay region of the San Francisco Bay Area. It served as the capital of California for nearly thirteen months from 1853 to 185 ...
on
I-680 Interstate 680 may refer to: *Interstate 680 (California), a connecting freeway between I-80 and I-280 in the San Francisco Bay Area, California *Interstate 680 (Nebraska–Iowa), a bypass in Omaha, Nebraska *Interstate 680 (Ohio), a loop through ...
also connects Contra Costa and Solano counties. * The
Antioch Bridge The Antioch Bridge (officially the Senator John A. Nejedly Bridge) is an automobile, bicycle, and pedestrian bridge in the western United States. Located in northern California, it crosses the San Joaquin River-Stockton Deepwater Shipping Chann ...
on SR 160 connects Contra Costa and Sacramento counties. * The
Dumbarton Rail Bridge The Dumbarton Rail Bridge lies just to the south of the Dumbarton road bridge. Built in 1910, the rail bridge was the first structure to span San Francisco Bay, shortening the rail route between Oakland and San Francisco by . The last freight ...
is an abandoned bridge that used to carry rail traffic. The
Transbay Tube The Transbay Tube is an underwater rail tunnel that carries Bay Area Rapid Transit's four transbay lines under San Francisco Bay between the cities of San Francisco and Oakland, California, Oakland in California. The tube is long, and attaches ...
, an underwater rail tunnel, carries
BART Bay Area Rapid Transit (BART) is a rapid transit system serving the San Francisco Bay Area in California. BART serves List of Bay Area Rapid Transit stations, 50 stations along six routes and of track, including eBART, a spur line running t ...
services between Oakland and San Francisco. Prior to the bridges and, later, the Transbay Tube, transbay transportation was dominated by fleets of
ferryboats A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus. ...
operated by the
Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials) was an American Railroad classes#Class I, Class I Rail transport, railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was oper ...
and the
Key System The Key System (or Key Route) was a privately owned company that provided mass transit in the cities of Oakland, Berkeley, Alameda, Emeryville, Piedmont, San Leandro, Richmond, Albany, and El Cerrito in the eastern San Francisco Bay Area ...
transit company. However, in recent decades, ferries have returned, primarily serving commuters from Marin County, relieving the traffic bottleneck of the Golden Gate Bridge (see
Ferries of San Francisco Bay San Francisco Bay in California has been served by ferry, ferries of all types for over 150 years. John Reed (Early Californian), John Reed established a sailboat ferry service in 1826. Although the construction of the Golden Gate Bridge and the ...
). The bay also continues to serve as a major
seaport A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manc ...
. The
Port of Oakland The Port of Oakland is the port authority for the city of Oakland, California, United States. Its primary responsibilities are the operation of the Oakland Seaport and the Oakland International Airport. It also operates a commercial real est ...
is one of the largest cargo ports in the United States, while the
Port of Richmond The Port of Richmond, also known as the Richmond Deepwater Terminal and the Richmond Marine Terminal, is located on the James River in Richmond, Virginia, United States, inland from Cape Henry and approximately northwest of Newport News, Virg ...
and the
Port of San Francisco The port of San Francisco is a semi-independent organization that oversees the port facilities at San Francisco, California, United States. It is run by a five-member commission, appointed by the mayor subject to confirmation by a majority of the ...
provide smaller services. An additional crossing south of the Bay Bridge has long been proposed.


Recreation

San Francisco Bay is popular for sailors (boats, as well as
windsurfing Windsurfing is a wind-propelled water sport that is a combination of sailing and surfing. It is also referred to as "sailboarding" and "boardsailing", and emerged in the late 1960s from the Californian aerospace and surf culture. Windsurfing gain ...
and
kitesurfing Kiteboarding or kitesurfing is a sport that involves using wind power with a large power kite to pull a rider across a water, land, snow, sand, or other surface. It combines the aspects of paragliding, surfing, windsurfing, skateboarding, snow ...
), due to consistent strong westerly/northwesterly thermally-generated winds – beaufort scale, Beaufort force 6 () is common on summer afternoons – and protection from large open ocean swells. Yachting and yacht racing are popular pastimes and the
San Francisco Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a List of regions of California, region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose, California, S ...
is home to many of the world's top sailors. A shoreline bicycle and pedestrian trail known as the San Francisco Bay Trail encircles the edge of the bay. The San Francisco Bay Area Water Trail, a growing network of launching and landing sites around the bay for non-motorized small boat users (such as kayakers) is being developed. Parks and protected areas around the bay include Eden Landing Ecological Reserve, Hayward Regional Shoreline,
Don Edwards San Francisco Bay National Wildlife Refuge Don Edwards San Francisco Bay National Wildlife Refuge (DESFBNWR) is a United States National Wildlife Refuge located in the southern part of San Francisco Bay, California. Its headquarters and visitor center are in the Baylands district of Fre ...
, Hayward Shoreline Interpretive Center, Crown Memorial State Beach, Eastshore State Park, Point Isabel Regional Shoreline, Brooks Island Regional Preserve, and César Chávez Park. The California Office of Environmental Health Hazard Assessment (OEHHA) has developed a safe eating advisory for fish caught in the San Francisco Bay based on levels of mercury or Polychlorinated biphenyl, PCBs found in local species. The San Francisco Bay Area Water Trail is a planned system of designated trailheads designed to improve non-motorized small boat access to the bay. The California Coastal Conservancy approved funding in March 2011 to begin implementation of the water trail.


Gallery


See also

*
Golden Gate The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by ...
*
Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...
* Hydrography of the San Francisco Bay Area * Islands of San Francisco Bay * J.C. Barthel, who prepared "plans for the docks and other water-front improvements in the San Francisco Bay district" * McLaughlin Eastshore State Park * Mount Diablo * Mount Tamalpais State Park * Napa Sonoma Marsh * Point Pinole Regional Shoreline, Richmond


References


Literature

*
The Bay of San Francisco: The metropolis of the Pacific Coast and its suburban cities: A history
'. Volume I. Lewis Publishing Company, Chicago, Ill. Published 1892
Contains index to biographical sketches

Volume II
– Biographies


External links


''San Francisco Bay: Portrait of an Estuary'', David Sanger and John Hart, University of California Press



''The Islands of San Francisco Bay'', James A. Martin , Michael T. Lee, Down Window Press

Army Corps of Engineers Bay Model: Working scale model of the Bay

SF Bay Kayak, Canoe, and Boat Launch Ramp guide. A collaboratively edited guide to the SF bay.

BoatingSF.com: Photos of SF Bay and its boats, plus online cruising guide

Save San Francisco Bay: Protect and Restore San Francisco Bay

sfbaywildlife.info
Guide to San Francisco Bay wildlife
Early History of the California Coast, a National Park Service ''Discover Our Shared Heritage'' Travel Itinerary

Cartography & History ''The representations of San Francisco Bay: a portable harbor in the fragile geography of the North Pacific''
* ''San Francisco Estuary and Watershed Science'': a peer-reviewed online science journal {{Authority control San Francisco Bay, Bays of California Bodies of water of Richmond, California San Francisco Bay watershed Estuaries of California Tourist attractions in the San Francisco Bay Area Ramsar sites in the United States Wetlands of California Bodies of water of San Francisco Bodies of water of Alameda County, California Bodies of water of Santa Clara County, California Bodies of water of Contra Costa County, California Bodies of water of Solano County, California Bodies of water of San Mateo County, California Bays of Marin County, California Estuaries of Marin County, California Bays of Contra Costa County, California Albany, California Berkeley, California