|NASA Photo ID||ISS051-E-12705|
|Time taken||13:55:58 GMT|
4928 x 3280 pixels 720 x 480 pixels 4928 x 3280 pixels 640 x 426 pixels
|Nikon D4 Electronic Still Camera|
|4928E: 4928 x 3280 pixel CMOS sensor, 36.0mm x 23.9mm, total pixels: 16.6 million, Nikon FX format|
|4928 pixels||3280 pixels||No||No||NASA's Earth Observatory web site||Download Image|
|720 pixels||480 pixels||Yes||No||NASA's Earth Observatory web site||Download Image|
|4928 pixels||3280 pixels||No||No||Download Image|
|640 pixels||426 pixels||No||No||Download Image|
An astronaut took this photograph of a section of Isla Mayor, an island in the delta of the Guadalquivir River in southwestern Spain. The Donana National Park is a marshland nature reserve that has been proclaimed a UNESCO World Heritage site. The larger, multi-colored geometric shapes in the scene are fish ponds, while the smaller, dark rectangles are rice fields.
The fish farming practiced here tries to mimic natural conditions - maintaining the original wetland conditions - more closely than many "intensive" fish farms around the world. These larger ponds are fed with river water, which contains natural food types, especially algae and shrimp, without commercial fish feed or antibiotics. Such larger fish ponds reduce problems, such as fish diseases and degradation of the pond water, and raise marketability. Species farmed here include sea bass, grey mullet, meagre, and shrimp.
Cattle raising and rice farming are being progressively phased out of the area as part of a wider plan to surround the Donana park with environments that resemble the original wetlands. The region is becoming one of the largest bird refuges in Europe, attracting almost 250 species of migratory birds each year. Fish taken from the ponds by birds - amounting to about 20 percent of the fish population - are viewed as part of an ecosystem in balance.