Saline Inland Waters

Abstract

Inland saline lakes are distributed worldwide in semi-arid (200–500 mm annual precipitation) or arid (25–200 mm) climatic zones and are often close to large population centers. Globally they have accounted for only slightly less water volume (0.008%) than their freshwater counterparts (0.009%). In fact, some of the largest lakes in the world are saline (e.g., Caspian Sea). Saline lakes display a large range in size, ionic composition, flora and fauna, and age (from ephemeral playa to ancient lakes). Saline lakes usually occur in hydrologically closed (endorheic) drainage basins. Approximately 1/10 of the Earth's surface area is made up of endorheic drainage basins. Saline lakes are extremely responsive to climate both within and between years. During droughts and exceptionally dry years they lose water volume through evaporation or evapotranspiration with concomitant increases in salinity (evapoconcentration of salts). Paleolimnological examination of cores from saline lakes has been used to predict the duration and frequency of droughts. Although saline lakes can be productive, biodiversity and productivity tend to decrease with increasing salinity. Worldwide, saline lakes have important ecological, economic, and cultural values. Currently one of the greatest threats to saline lakes is anthropogenic or secondary salinization as a result of human activity (industry, agriculture, construction) in a lake basin.