Wetlands are habitats which periodically have wet, waterlogged soils or are covered with a relatively shallow layer of water. Wetlands are located in low-lying areas where rain and groundwater help keep them saturated. Wetlands are home to a great variety of animals including birds, mammals, fish, amphibians and insects. Water levels increase during the winter because of the rain and decrease during the summer when it is dryer. Quicksand does not occur in swamps.
Swamps can actually have as little water as just a few inches or none at all in the dry season.
The high acidity, cold year-round temperatures, and limited oxygen supply, due to poor water circulation, discourage bacteria and other decomposers from breaking down material. There are wetlands in Israel. 90 percent of the wetlands that existed 200 years ago in what we now call California have been destroyed. The Delta and Bay drain an area of about 60,000 square miles which is about 40 percent of the California landscape. In 1850, there were 545,375 acres of tidal wetlands in the Delta and Bay.