SAN FRANISCO BAY By: Randall Alcorn

Golden Gate Bridge

History of the Bridge Took over 4yrs to construct Costs $35 million dollars 1.7 miles long in length Opened May 28,1937

Alcatraz

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

The Bay Area

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

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

SAN FRANCISCO BAY The development

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

San Pablo Bay

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

San Francisco Bay Estuary

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

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.

Tidal Marshes 190,000 acres now only 16,000 The “kidneys” of Bays, purifying pollutants Produce large amounts of plant material

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

Tidal Marshes in 1900

Tidal Marshes 1990

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)

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

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

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

Programs to help restore wetland habitats Ducks Unlimited San Pablo Bay National Wildlife Refuge San Francisco Bay Joint Venture

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.