Salt ponds in the San Francisco Bay
The salt ponds in the San Francisco Bay (San Francisco Bay salt ponds) are the largest man-made salt pans for salt production in the United States . On an area of 720 km², salt is produced here for the food industry as well as for a variety of industrial purposes, such as chlorine bleaching and plastics processing . Most of the area is currently cultivated by Cargill, Inc. , which extracts and processes over 650,000 tons of salt annually. In addition to the salt ponds , the region largely consists of marshland and salt marshes , which offer a habitat for an immense biodiversity. In total, the marshland serves as a habitat for over 10,000 different animals.
history
Originally, the San Francisco Bay from the Indian tribe who had Ohlone people settled that already in the marshlands in the south of the bay their own need for salt by specially constructed smaller salt pans covered. With the settlement of white immigrants in the middle of the 19th century, the salt industry in the region also boomed, and large-scale salt pans were built. In order to meet the increasing demand, larger and larger evaporation basins were built over the next few years. The marshland had to give way more and more to the salt flats. It was not until the end of the 1960s that first efforts were made to preserve and restore the endangered biotope. Environmental protection associations insisted on the establishment of a state nature reserve. In 1974, the Don Edwards San Francisco Bay National Wildlife Refuge was actually established as the first nature reserve in the United States to be located in the immediate urban catchment area. 2003 bought the land California for 100 million US dollars from the Cargill Corporation good 66 km² land back, which in the hitherto most complex restoration project to irrigate again in US history and stand as a new habitat available.
Color differences
The different colors of the individual salt ponds result from the presence of different microorganisms depending on the salt content : The color is therefore an indicator of the salinity . Green algae dominate in ponds with a low salinity, while phototrophic halophiles , whose pigments ensure the increasingly intense reddish tint, multiply with increasing salinity .
Footnotes
- ↑ Archived copy ( memento of the original dated February 6, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ http://www.fws.gov/desfbay/index.htm
- ↑ Archived copy ( memento of the original from September 25, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
Web links
- Cargill Corporation information
- South Bay Salt Pond Restoration Project website
- Site of the Don Edwards San Francisco Bay National Wildlife Refuge
- Article in the "Bay Nature" magazine about environmental protection issues (PDF file; 1.46 MB)
Coordinates: 37 ° 28 '55 " N , 122 ° 0' 40" W.