|Publication Type||Book Chapter|
|Year of Publication||2009|
|Book Title||Encyclopedia of Inland Waters|
Salinization of inland waters has been recognized as an environmental problem in arid and humid regions of the world. Chloride is an important anion in many salts, which is typically only present in few milligrams per liter in inland waters that are minimally disturbed, but can reach concentrations of several grams per liter in arid environments (affected by irrigation) and humid environments (affected by road deicer use). Chloride concentrations and salinization are increasing in many inland waters as a result of these activities. Elevated chloride concentrations contribute to a variety of ecological effects such as acidification of streams, mobilization of toxic metals from soils through ion exchange, effects on mortality, and reproduction of aquatic plants and animals, alterations of community composition of plants in riparian areas and wetlands, facilitation of invasion of saltwater species into previously freshwater ecosystems, and interference with the natural mixing of lakes. Chloride is retained biotically and abiotically in watersheds and inland waters contributing to long-term increases in concentrations. Chloride retention may require consideration in ecological and hydrologic studies that use chloride as a conservative tracer. Knowledge gaps include mass balance studies of chloride across different aquatic systems, isotopic tracer studies to delineate sources, and solute injection experiments to determine salinization potential based on geomorphology.