SAN FRANISCO BAY By: Randall Alcorn. Golden Gate Bridge.

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SAN FRANISCO BAY By: Randall Alcorn

Transcript of SAN FRANISCO BAY By: Randall Alcorn. Golden Gate Bridge.

Page 1: SAN FRANISCO BAY By: Randall Alcorn. Golden Gate Bridge.

SAN FRANISCO BAY

By: Randall Alcorn

Page 2: SAN FRANISCO BAY By: Randall Alcorn. Golden Gate Bridge.

Golden Gate Bridge

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History of the Bridge

• Took over 4yrs to construct

• Costs $35 million dollars

• 1.7 miles long in length

• Opened May 28,1937

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Alcatraz

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History of Alcatraz “Rock”

• Converted to Federal prison in 1934

• Thought had the perfect area for a prison

• 34 people tried to escape

• Closed March 21, 1963

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The Bay Area

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About the Bay

• 55,572 acres• 16,000 sq. miles• 50mi. Long and 3-13mi.

wide• 40% fresh water drains

into bay• Extends from California’s

San Pablo Bay to South San Francisco Bay

• 4 areas of the bay the north, central, and south San Francisco Bay, and San Pablo Bay

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About the bay (cont.)

• 400ft is deepest area

• Relatively shallow, channel on 50 ft exists

• One of the most important coastal wintering and migratory habitats for Pacific flyway waterfowl

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SAN FRANCISCO BAY

The development

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Development (cont.)

• The bay was formed 10,000 yrs ago during the last ice age.

• Sea levels rose and inland through the “golden gate”

• Levels were rising at 1” per year, along with rivers and creeks coming into the area

• Sedimentation occurred

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San Pablo Bay

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San Pablo Bay (cont.)

• Shallow tidal estuary• 10mi. Across and

covers app. 90 sq miles

• Mostly fresh water but contains salt marshes and also mudflats

• Sacramento and San Joaquin Rivers empty

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San Francisco Bay Estuary

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Estuary

• Nation’s second largest/most biologically significant estuary on the Pacific Coast

• Made up of San Francisco Bay (north, south, and central) and the San Pablo Bay

• Interconnecting wetlands (sloughs, marshes, channels, rivers)

• Some areas are mixed salt/fresh water

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Habitats

• Tidal Flats- Areas that are flooded during high tide and lose most the water during low tide

• Tidal Marsh- Areas flooded by high tide but retain some water during low tide.

• Seasonal Wetlands- Moist grassland and vernal pools.• Riparian Habitat- Boards creek, rivers, lakes• Non-tidal diked wetlands- Tidal marshes that are

isolated from tidal influence and maintain wetland features.

• Salt ponds- Large man-made ponds that are flooded with Bay water.

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Tidal Marshes

• 190,000 acres now only 16,000

• The “kidneys” of Bays, purifying pollutants

• Produce large amounts of plant material

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Tidal Marshes (cont.)

• Important for fish and waterfowl

• Vegetation consists of algae, sea lettuce, and eel grass

• High tide fish use the area for forage

• Low tide fish eating birds consume fish, that didn’t make it out

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Tidal Marshes in 1900

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Tidal Marshes 1990

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Salt Ponds

• San Francisco Bay offers good area for salt production (Cargill Salt Company)

• Water is brought in from the bay into man-made ponds

• Provides food and habitat for more than 70 species of waterfowl and shorebirds

• San Francisco Bay Wildlife Refuge bought 16,500 acres of salt ponds (one of largest restoration attempts in America)

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Salt Pond (cont.)

• 300 million dollars

• Take five years to fully restore but hope to:– Increase bays tidal wetland by 50%– Preserve open space– Improve water quality– Act as natural flood control – Prevent shoreline erosion – Provide habitat for endangered species

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Importance of Wetlands in Bay

• San Francisco is heavily polluted, wetlands help filter pollutants.

• Soak up excess water, that could flood the bay

• Provides home for endangered species

• 70% of commercial fishing

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Wetlands destroyed

• (Human influence) They are cheap, provide go location for business and are easy to build on.

• Exotic species brought in from ships

• They push out native species of plants and animals.

• 100 exotic species

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Programs to help restore wetland habitats

• Ducks Unlimited

• San Pablo Bay National Wildlife Refuge

• San Francisco Bay Joint Venture

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Programs (cont.)

• Ducks Unlimited• 20,000 acres of habitat• Help to directly benefit

endangered species and sensitive species

• Habitat improvement for waterfowl: lesser scaup, canvasback, northern pintail, and redhead.

• San Pablo Bay NWR• Open bay, tidal marshes,

mudflats, and seasonal and managed wetlands

• Marches have been greatly impacted; agriculture, draining, industrial use and water diversions

• 85% wetlands been altered.

• Refuge provides area for migratory waterfowl species.

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