Ephemeral Aquatic Environments
An ephemeral aquatic environment is a body of water that exists for only a very short time. It may be a shallow lake, an arroyo, a stream or spring, or even a small pool or puddle. In the desert it is common for lakes to appear in low basins where rainwater collects after running off of the slopes. These lakes that are formed are called playas, or ephemeral lakes. An ephemeral lake has no outlets, so the water stays until it evaporates, is absorbed into the groundwater, or is consumed by animals and plants. When the water is gone, it leaves behind plants and animals waiting for the lake to once again fill up with the water that gives them life. In some cases, as with the desert shrimp, the adaptations the animals have made in order to survive the drying periods are truly amazing.
As the water evaporates, it may leave behind concentrated deposits of saline and gypsum, forming an unusual landscape. One example is the White Sands National Monument near Alamogordo, New Mexico. Gypsum deposits from Lake Lucero continue to build the white sand dunes that cover more than 275 square miles. It takes special animal and plant adaptations to live in this constantly shifting sand and dry environment. Some of them have even become white for better camouflage from their enemies.
Animals and plants have been living around these lakes and pools since prehistoric times. Dinosaur tracks have been discovered in the lakebed of Lake Otero, a prehistoric ephemeral lake. Many amphibians, such as the Plains Leopard Frog, the Rio Grande Leopard Frog, and Couch's Spadefoot currently thrive in these dry lakebeds, using the water that is periodically collected in the ephemeral lakes to reproduce. These same amphibians can even live out their life cycles by making use of the puddles from summer rains when larger ephemeral bodies of water are not available. Today, ephemeral aquatic environments provide habitat for numerous species of animals and plants. The water that is available, although temporary, gives them the essential ingredient to enable them to live in the desert.