Saline lake ecosystems of Mexico

Abstract

This paper aims to draw attention to the need to better know and understand Mexican saline lakes. It does this by outlining their distribution, abundance and location and their physical, chemical and biological characteristics. The influence of climatic factors on saline lakes is discussed. To sharpen the focus of the general discussion, a few Mexican saline lakes are discussed in more detail in each of the indicated topics. Saline lakes are found throughout Mexico, with the greatest number in the northwest and the least in the southeast, and from sea level to altitudes above 2000m. Mexican saline lakes widely fluctuate morphometrically. The majority are tiny, shallow, and temporal with small volumes. Some are large or deep, and perennial with large volumes. Polymixis is common in shallow lakes while deeper ones are monomictic. Temperature and dissolved oxygen fluctuate widely. Alkaline waters are frequent. Mirroring high primary productivity rates, water is often green and turbid but other colors (blue, sepia, purple, yellow) and clear water are also found. Most lakes are sodium chloride or alkali carbonate types. Salts resulting from the combination of sodium with chloride, carbonates and sulfates are common and, to a lesser extent, salts of calcium, potassium, magnesium, lithium and boron are present. Species richness in Mexican saline lakes decreases as salinity rises. Hyposaline lakes display a more diverse biota than hypersaline ones. Organisms commonly found in Mexican saline lakes are: blue-green algae (e.g., Spirulina geitleri, Phormidium tenue), rotifers (Brachionus spp.), anostracans (Artemia spp.), copepods (e.g., Diaptomus, Leptodiaptomus), corixid bugs (e.g., Corisella, Krizousacorixa, Trichocorixella), ephydrids (e.g., Ephydra hians), the neotenic salamander (e.g., Ambystoma spp.), atherinids (e.g., Chirostoma spp.), goodeids (e.g., Goodea spp.), cyprinodontids (e.g., Cyprinodon spp.), poecilids (e.g., Gambusia spp.), and the Caribbean pink flamingo (Phoenicopterus ruber ruber).