Freshwater Wetlands
Swamps, marshes and bogs are all freshwater wetlands. Swamps are wet or dry for periods of time throughout the year and can support a variety of trees and bushes. Marshes are wet throughout the year and are usually found at the edges of rivers, lakes and ponds. Marshes usually support a variety of grasses and other soft-stemmed plants. Bogs are either covered by a very shallow layer of water or no visible water at all. The ground of a bog is made of plants called sphagnum moss that causes the ground to be moist and soft like a sponge and soaked with water. The sphagnum moss can be harvested as peat and later used as either fertilizer or burned as fuel.

Saltwater Wetlands
Saltwater wetlands include mangrove swamps, saltwater marshes and estuaries. Mangrove swamps are found in tropical and subtropical areas, such as the Everglades in Florida, the Caribbean, Panama, Indonesia and the Philippines. A mangrove is a species of saltwater tolerant tree or shrub. Saltwater marshes are wet throughout the year and are found at the edges of saltwater bodies of water. Like their freshwater counterparts, saltwater marshes support a variety of grasses and other soft-stemmed plants. Estuaries are located where a river empties into an ocean or sea. The water in an estuary is a blend of fresh and saltwater. The salinity (saltiness) of the water depends on how far it is from the open ocean.

Estuaries contain one of the richest sources of life on the planet. This is because of the great amount of silt and nutrients from decaying plants that are transported by rivers into estuaries. The upwelling of ocean currents also causes nutrients to be washed up from the depths of the ocean. The nutrients allow bottom-dwelling plants and seaweed to flourish. Also, the nutrients support and encourage the growth of phytoplankton, forming the first critical link of a vast food chain. The presence of phytoplankton supports other links in the food chain: shellfish, insects, amphibians, fish, birds, mammals and other marine life. In fact, an estimated 90% of all marine fish and shellfish caught come from the third of the ocean closest to the world's coasts.

The Destruction of the Wetlands
Despite these and other benefits, saltwater and freshwater wetlands continue to be destroyed at an alarming rate. Some areas of the United States have lost as much as 90% of their wetlands. This is especially significant when you consider that more than 50% of the population lives within 50 miles of the coast in areas once home to vast wetlands.

Because the nation's coasts are so popular, they have rapid and dense urban growth at the expense of wetland areas. Beachside communities are, therefore, especially vulnerable to the impacts of urban byproducts, such as increased soil erosion and storm drain pollution. Beach erosion (loss of sand) is caused naturally by both wave and wind action. However, when wetlands are destroyed, the loss of seagrasses and other vegetation speeds up the natural erosion process by removing the natural anchors that hold the sand in place. A storm drain is designed to carry excess rainwater from city streets to a nearby body of water, such as an ocean. As wetlands are destroyed along the nation's coasts, so, too, is nature's ability to filter excess nutrients and pollution carried in storm drains prior to them reaching the ocean. More stress is then put on the ability of a surrounding ocean to break down excess nutrients and pollution. The end results include polluted coastal beach communities and further damage to delicate coastal food chains that creatures, including people, rely on for food.

The Ballona Wetlands
Within Los Angeles County, the Ballona Wetlands are the last large coastal wetlands. Located in Playa Del Rey, just a few minutes northwest of Los Angeles International Airport, the Ballona Wetlands were formed during many thousands of years by deposits of sediment from the Los Angeles River. These wetlands remained productive and undisturbed until the early part of the 20th Century. They were gradually filled and drained during the past 70 years to make room for the development of Venice, oil wells and Marina Del Rey.

In addition to county and federal government agencies, environmental organizations are also very concerned about wetlands and coastal waters. Environmental organizations such as Heal the Bay, Surfriders Foundation, Friends of the Ballona Wetlands and other local area environmental groups monitor wetland and coastal water issues, educate the public and work with government agencies to protect and restore local area wetlands and coastal waters.

What Are the Benefits of Wetlands?
Besides supporting a diversity of life, estuaries and freshwater wetlands provide other benefits:

• Flood Transportation and Storage: Just as a highway transports vehicles, the floodways of a wetland allow floodwater to move harmlessly downstream by storing water and slowly releasing it.

• Sediment Containment: Loss of sediment is prevented by a coastal wetland's ability to reduce the flow of floodwater. This allows sediment to be replenished.

• Wave and Erosion Barriers: Impacts of storm tides and waves to upland areas are reduced by coastal wetlands.

• Water Purification: Wetlands naturally filter excess nutrients and pollution. This helps improve overall water quality.

• Wildlife Habitat: Wetlands support a variety of wildlife by serving as spawning and nursery areas, and as sanctuaries for rare and endangered animals.