Clear Lake (California)
| Clear Lake | ||
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| On the shores of Clear Lake | ||
| Geographical location | Lake County, California | |
| Tributaries | various streams | |
| Drain | Cache Creek → temporarily Sacramento | |
| Places on the shore | Lakeport , Clearlake | |
| Data | ||
| Coordinates | 39 ° 3 ′ N , 122 ° 48 ′ W | |
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| Altitude above sea level | 401 m | |
| surface | 177 km² | |
| length | 30.6 km | |
| width | 12.8 km | |
| volume | 1.42 km³ | |
| Maximum depth | 18 m | |
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particularities |
oldest lake in North America, largest natural lake in California |
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The Clear Lake (English for "Klarer See") is a lake in Lake County in the US state of California . It is 30.6 km long, 12.8 km wide and has an area of 177 km². The lake is on average 8 m deep, at its deepest point its depth is 18 m. Due to a geological feature, it is believed to be one of the oldest lakes in North America. The Clear Lake AVA wine region extends around the lake .
Biomagnification of DDD
One of the classic cases of environmental damage from biomagnification occurred at Clear Lake . At the end of the 1940s there was a colony of about 1000 breeding pairs of racing divers there . In 1949 the colony did not breed for reasons that were initially unknown. In December 1954 over 100 racing divers died at the lake, in December 1957 another mass extinction of the birds occurred. Since none of the usual explanations seemed to work, the body fat of dead racing divers was finally analyzed and found to be 1600 ppm DDD . The chemical, which is structurally very similar to DDT , was first used against the Clear Lake Gnat , a species of mosquito , in September 1948 . The first application, which resulted in a concentration of 14 ppb DDD in the lake water, killed 99% of the mosquito larvae in the sea mud. The mosquito population remained lower than usual in the following years. In September 1954 and 1957, DDD was therefore again introduced into the lake; the DDD concentration in the lake water was then about 20 ppb in both cases. Because of these very low concentrations, no one suspected a connection to the deaths among the racing divers. However, the DDD released had accumulated via the food chain , the DDD concentration in plankton was already 265 times as high as in water, in predatory fish and birds it was increased by a factor of 85,000.
Bloody Island massacre
Pomo Indians, enslaved by white settlers Andrew Kelsey (after whom a lakeside town is named) and Charles Stone, revolted in 1850, killing Kelsey and Stone. Thereupon soldiers of the 2nd US Infantry Regiment under Lieutenant Nathaniel Lyon advanced against them, surrounded them on the island of Bo-no-po-ti in the north of the lake and killed over 200, including women and children.
Web links
- Clear Lake, Lake County, California in the United States Geological Survey's Geographic Names Information System
- Bloody Island Massacre
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- ↑ Thomas R. Dunlap, DDT: Scientists, Citizens and Public Policy , Princeton University Press, 1981, ISBN 0-691-04680-8 , pp. 94-96