So it is not surprising that, although many old ponds look natural, most of them are man-made. In recent years, country ponds filled with lily pads and frogs have almost disappeared. Many have been drained or polluted. As a result, the backyard pond is becoming an increasingly valuable refuge for may aquatic species. Like lakes, ponds provide homes and breeding spots in their shallow fresh waters, to a collection of species.
Natural ponds are fragile, often temporary habitats.
Their water supplies can dry up, their banks can wash away, or they can dry up because the silt and plant debris that clog them up. In the past, if one pond dried up, another formed. Today natural ponds rarely occur in wet or marginal land that has been drained for agriculture. Larger, well-built artificial ponds tend to last longer, but often become too much trouble to keep up and are drained or allowed to dry out. Domestic waste, from tin cans to old tires, pollutes many ponds.