Pond/Lake Information:


Ponds and lakes occur all over the world, with frozen ponds at the poles to tropical lakes at the equator. Clear lakes are called oligotrophic because of their lack of nutrients. They occur at high altitudes where there are low levels of animal and plant life around them making nutrient runoff into the lake low. Oligotrophic lake water is often suitable for drinking after filtration. Lowland lakes and ponds are often eutrophic with cloudy/green water because of the large animal and plant populations around them. Eutrophic lakes are high in nutrients and usually not suitable for drinking. Pond/lake temperatures are stratified (layered) with the highest temperatures near the surface in the summer. This occurs because there is no river-like mass flow of water. The shallows are called the littoral zone, containing most of the life of the lake. The limnetic zone is the open area of the lake which is too deep for rooted plants. Algae are the major producers here, with cattails, water willows, lilies, hyacinths, and baldcypress being common plants growing at the water's edge. Animals include many insects, waterfowl (ducks), fish (bass, sunfish, minnows, gar, catfish), amphibians (frogs and salamanders), and reptiles (snakes).



An alpine lake at low altitude, with lilies near the edge.
By skuensting


An alpine lake in Glacier National Park, Grinnel Glacier.
By skuensting


An alpine lake in Glacier National Park.
By skuensting


An alpine lake near Breckenridge, CO.
By skuensting

Distribution:
Ponds and lakes are found worldwide where there is enough rainfall to fill a depression in the ground.