U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2007–3097

December 2007

CALIFORNIA

Pacific 

Ocean

NEVADA UTAH

ARIZONA

MEXICO

San Diego

El Centro

Los Angeles

Palm Springs

Whitewater River

Alamo 

River

New River

RIVERSIDE CO

IMPERIAL CO

SAN 

DIEGO 

CO

Salton Sea

86

10

111

78

The USGS Salton Sea Science Office – 

The U.S. Geological Survey’s (USGS) Salton Sea Science 

Office (SSSO) provides scientific information and evaluations 

to decisionmakers who are engaged in restoration planning 

and actions associated with the Salton Sea. The primary 

focus is the natural resources of the Salton Sea, including the 

lake’s ability to sustain biological resources and associated 

social and economic values.

•	 Science leadership and coordination

•	 Science oversight and responsibility for 

restoration project science activities

•	 Administration of science funding

•	 Science contract awards and 

negotiations

•	 Science outreach activities

•	 Development and delivery of peerreviewed science products

•	 Collaboration and coordination with 

the restoration project management 

agencies

•	 Networking with external agencies and 

organizations for data sharing and other 

restoration project science needs

•	 Accountability and reporting for the 

science program

The Salton Sea Science Office

The SSSO was established in 2000

in response to a request from the Deputy

Secretary for the Department of the

Interior to provide “continuity of the

science effort, effectiveness of the

science undertaken in support of the

restoration project, and efficiency of

operations in serving management needs

....” (from the 2000 Strategic Science

Plan Salton Sea Restoration Project).

Working closely with federal, state, local,

nongovernmental, and tribal partners,

the SSSO has provided information for

management actions under the Salton

Sea Ecosystem Restoration Program.

For additional information regarding

the program, please visit

http://www.saltonsea.water.ca.gov/.

SSSO History and Activities

The Salton Sea, California’s largest

lake, was created by a Colorado River

levee break in 1905. The lake is about

35 miles long, 15 miles wide, and 30

feet deep. The surface elevation is about

228 feet below mean sea level. The

sea has high salinity averaging 48,000

milligrams per liter, which is about 37

percent greater than the salinity of the

Pacific Ocean. Most inflow now comes

from agricultural drainage from the

Whitewater, New, and Alamo Rivers.

Water leaves the Salton Sea by

evaporation: it has no outflowing

rivers or streams.

General Characteristics 

of the Salton Sea

Map showing location of Salton Sea

The SSSO collaborates with the State

of California to link state and federal

managers with the scientific community.

The results of numerous peer-reviewed,

integrated scientific studies coordinated

or conducted by the SSSO have been

considered in the selection of a preferred

alternative for restoration. In addition,

the SSSO is working with the Bureau

of Reclamation to assess models that

predict risks of contaminants to birds.

USGS scientists also are exploring the

potential for large-scale uses of artificial

saline habitat based on a constructed

wetland complex. The SSSO is helping

to design an integrated monitoring and

assessment plan and other plans for Early

Start Habitat—an effort to create shallow,

saline habitat for birds and fish to use as

the lake’s salinity increases beyond most

biological tolerances.

Scientist sampling aquatic invertebrates

Printed on recycled paper Printed on recycled paper

Black-necked Stilt

California 

Brown

Pelican
Number of birds encountered or recovered.

Encountered birds are those that are recaptured 

while recovered birds are those found dead.

Gulf of 

Mexico

Pacific Ocean Prairie Pothole 

Region

Louisiana-Texas

Gulf Coast

 1 - 100 birds

101 - 300 birds

301 - 600 birds

601 - 3,601 birds

PACIFIC FLYWAY CENTRAL FLYWAY

MISSISSIPPI 

FLYWAY

ATLANTIC

FLYWAY

Mexico

United States

Canada

Arctic Ocean

Hudson Bay

Birds Banded at the Salton Sea

Courtesy of University of Redlands

Authors:

Harvey Lee Case III (760-777-1574) email: hlcase@usgs.gov

Douglas A. Barnum (760-777-1564) email: doug_barnum@usgs.gov

Graphic Design: Bill Gibbs

Photo Credits: All photographs taken by U.S. Geological Survey 

employee Douglas A. Barnum

Mailing Address: Suite R, 78-401 Hwy 111, La Quinta, CA 92253

For additional information regarding the Salton Sea Science Office, visit 

the website http://www.usgs.gov/saltonsea/.

American Avocet

Black Skimmer

Great Egret

Caspian Tern

Killdeer on nest

Burrowing Owl

Proposed water transfers from

agricultural uses in the Imperial Valley

to municipal uses in southern California

will decrease agricultural return flow to

the Salton Sea. Unless mitigation actions

are taken, the reduced flow will result

in loss of aquatic and wetland habitat,

increased salinity, a lower lake level, and

degraded air

quality. The

California

Secretary for

Resources

recently

recommended

a preferred

alternative

and funding

plan to the California State Legislature.

The alternative calls for creation of a

45,000 acre horseshoe-shaped marine

lake in the

northern sea and

the development

of 62,000 acres of

saline habitat in

the southern and

northern parts of

the basin. The

estimated capital

cost of implementing the preferred

alternative is about $9 billion, and

annual operation and maintenance

needs are about $142 million.

USGS scientist radio marking stilt chick

A Sea in Transition

The Salton Sea is a critical stop for migratory birds on the Pacific and Central Flyways. 

More than 400 species of birds, including 80 percent of the western population of white pelicans 

(Pelecanus erythrorhynchos) and 20 species of concern, use the system. Birds banded at the 

Salton Sea and reported to the USGS Bird Banding Laboratory have been recovered throughout 

North America. The combination of avian biodiversity and importance as a breeding habitat is 

unsurpassed by any limited geographic area within the contiguous 48 states and Latin America.

Why care?

Without mitigation, human health in Mexico and in the Coachella and Imperial Valleys of 

California could be affected by increased amounts of windborne dust as the lake’s level 

declines and sediments currently underwater are exposed. Department of the Interior-owned 

and managed lands under parts of the current sea may be exposed and contribute to air quality 

concerns as shorelines recede with lowering lake levels. These lands include Native American 

trust lands and parts of the Sonny Bono Salton Sea National Wildlife Refuge. In addition, the 

discovery in July 2007 of significant numbers (estimated to exceed 1,000) of desert pupfish 

(Cyprinodon macularius) in the wetland complex presents a unique opportunity to assess the 

factors influencing the survivability of this federal- and state-listed endangered fish.