Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

View Plant Indicator Data

What Is This Indicator, and Why Is It Important? This indicator reports the acreage of coastal habitats whose defining feature is that they are composed of living organisms (such as seagrasses, mangrove forests, and coastal wetlands) or are built by them (such as coral reefs or shellfish beds). These areas provide habitat for many other organisms, and in some cases (such as shellfish beds) they continue to do so even after the animals that built them are no longer living.

Loss of habitat is a major cause of the decline of coastal species. The habitats described here are critical for many species of crabs, fish, and seabirds, as well as for smaller animals that provide food for these larger creatures. When these habitats decline in area, organisms that depend on them are lost or displaced.

What Do the Data Show? From the mid-1950s to the mid-1990s, wetland acreage on the Atlantic and Gulf coasts declined by about 8%. Four hundred thousand acres of coastal wetlands, out of a total of 5 million acres, were lost, although the rate of loss slowed in the 1990s.

Why Can't This Entire Indicator Be Reported at This Time? Data for coral reefs and seagrasses and other “submerged aquatic vegetation” are available for many areas, but these data have not been synthesized to produce national estimates. (A federal task force has developed a 5–7-year plan for mapping all coral reefs in U.S. waters.) Data on the area of shellfish beds are available, but changes in the area covered by monitoring programs may obscure changes in the area of shellfish beds. Data on vegetated wetlands are available only for the East (Maine to Florida) and Gulf coasts.