San Francisco Bay

Why protect fish?

Indicators of water quality

Indicators of river and estuary habitat quality

Essential links in our ecosystem

Food (& jobs related to food)

Recreation

Sacred

How are fish essential links in our ecosystem?

Fish migration facilitates nutrient and energy flow between habitats, including agriculture

True or false: Freshwater fish are more diverse than any other group of vertebrate species?

True

How much of the world’s surface is covered by freshwater?

3%

How many species of freshwater fish are there?

~18,000 species

How much of all freshwater fish are endangered?

1/3

Studies show that fish…

Transfer ocean derived nutrients and energy upstream to forests and vineyards.

__ major rivers drain __ of California’s land area (up to 40% in wet years)

10, >1/3

San Joaquin River is..

the 2nd longest in California

Central Valley

Sacaramento River and is the largest in California.

California’s Central Valley Watershed: its delta

Central node for freshwater flow and water exports in California

Gateway for fish migration to/from Central Valley rivers

The Sacaramento River Delta

An inverted Delta that receives inflow from the Central Valley’s rivers.

Suisun Marsh

Largest brackish (mix of salt water and freshwater) on the West Coast of the Americas

San Francisco Bay

Includes 4 open water embayments including South Bay, San Fransisco Bay, San Pablo Bay and Suisun Bay,

Pelagic, open water estuarine habitat

San Franscisco Bay Estuary Watershed and its Aquatic Diversity

Around 40 native fish species overall

Four unique Chinook Salmon populations

Central Valley Steelhead

Two species of sturgeon (white and green)

Five endemic fish species

Two extinct species

__% of California’s fishes are extinct or at-risk of extinction in this century

83

Within the San Joaquin River basin, _ of the 21 native fish species are now “uncommon, rare, or extinct”

8

Fish habitat includes

Water chemistry

Predator/competitors

Currents

Food

Physical substrate

Temperature

Three major drivers of fish decline in the San Fransisco Bay Esturary Watershed

Direct habitat loss

Unsustainable water diversions

High water temperatures

Threat 1: Direct habitat loss

Blocked access to, or destruction of habitats from migration blocked by dams, levees, and wetland draining and conversion

Threat 2: Unsustainable water diversion & storage

Water volume (flow and reservoir storage) influences most aspects of fish habitat. Change in streamflow impacts water temperature, channel geomorphology, habitat diversity, and more.

Threat 3: High water temperatures

All fish life-stages are affected by water temperature. Water temperature affects survival, growth, distribution, and development.

Limited access to coldwater habitats because the central valley dams block access to high elevation coldwater spawning and rearing habitats for migratory fishes. Also because reservoir management affects river temperatures downstream. Lastly because climate change threatens to further limit the area and time period in which suitable temperatures exist for native fish.

Chinook Salmon

They spawn in freshwater, migrate to the ocean as juveniles, and return to spawn as adults.

However they’re losing access to cold water habitats upstream of dams and behind agricultural levees. Reservoir operations and unsustainable water diversions cause low river flow and high river temperatures

Climate change is also warming the waters, changing the hydrololic patterns.

There are two endangered runs of this type of fish.