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The Salton Sea. By: Christine Yafuso. Background. Located in Southeastern California About 1000 km 2 in size Largest lake in California Formed between 1904-1907 by accidental flooding of Colorado River (started as freshwater) which eventually filled the Salton Basin
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The Salton Sea By: Christine Yafuso
Background • Located in Southeastern California • About 1000 km2 in size • Largest lake in California • Formed between 1904-1907 by accidental flooding of Colorado River (started as freshwater) which eventually filled the Salton Basin • Repository for agricultural wastewater Picture: Salton Sea Authority, California Government 2000
Inflow • Greatest (78%) from major surrounding rivers: Alamo & New • Agriculture accounts for 8% • Ground Water only 4% Picture: Salton Sea Authority, California Government 2000
Characteristics • Chemical & Physical • Nutrients • Metals • Organic Compounds • Ecological • Fish • Birds Picture: Salton Sea Authority, California Government 2000
Salinity • Currently at about 45 ppt • Causes • No surface outflow • Evaporation • Increased input of saline • Increased input of nutrient rich agricultural drainage water Picture: Riedel & Costa-Pierce 2002
Dissolved Oxygen • Low concentrations • Decreases with depth • Rivers flowing into sea also have low concentrations • Average percentages of saturation of dissolved oxygen concentrations for 2 main rivers: Alamo (77.3) & New (66.2) • Main Causes • High eutrophic system • Frequent algae blooms Picture: Barnum et al 2002
Nitrogen & Selenium • Enter Salton Sea (by way of rivers) in high concentrations • N from chemical fertilizers • Se from water used for irrigation • Removal by anoxic sediment from floor • Result: Lower concentrations of N & Se, however, produces noxious odor
Problems • Major cause: No Outflow! • Results in: • High salinity • Low dissolved oxygen levels • Harmful odors (From removed N & Se) • Leads to: • Ecological crisis…
Effects on Fish • 1999: 7.6 mil tilapia and croakers died • Other contributing factors • Toxic ammonia contents & temperature stresses Picture 1: Gulf croakers die-offs Picture 2: Tilapia die-offs Cohn 2000 Desai 2000
Effects on Birds • 1996: About 15,000 birds died-10,000 of them pelicans • Cause: Disease • Avian botulism (bacterial infection): toxin produced by bacteria at high temps & low levels of dissolved oxygen • Paralyzes muscles Picture: Slack 1997
Restoration Alternatives • 1) Ecological • Fish Harvesting • Fish & Wildlife Disease Control • Wetland Reclamation • 2) Technical • Displacement Dikes • Enhanced Evaporation Systems • Solar Ponds • 3) Societal • Enhance Infrastructure • Improve economic status
Goals • Maintain as agricultural drainage reservoir • Restore wildlife & habitat • Encourage more recreational use • Suitable for economicaldevelopment