Review the indicators at a glance

The coasts and oceans of the United States extend from the narrow ribbon of shoreline that defines the water’s edge out some 200 miles into the open ocean. The cold and rocky coast of Maine and the mangrove swamps of Florida, the glacial fjords of Alaska and the black lava cliffs of Hawaii, the seagrass beds of the Chesapeake Bay and the pebble beaches of California—all these and more are found along the thousands upon thousands of miles of U.S. coastline. Offshore, kelp beds, coral reefs, and the open ocean provide habitat for fish, shellfish, birds, and mammals, as well as recreational and economic opportunities for many Americans (more than half of all Americans live within 50 miles of the coast). This vast expanse and the myriad plant and animal species that inhabit it are defined by the interaction between land and sea, between fresh water and salt water, an interaction that produces a rich mix of species and also of human activities.

What can we say about the condition and use of U.S. coasts and oceans?

Sixteen indicators describe the condition and use of America’s coasts and oceans. Partial or complete data are available for nine of the indicators. Of these, five have a data record that is long enough to judge trends, and three have a federally adopted reference point or other type of benchmark for comparison. For seven indicators, we report no data. In five of these cases, some data exist, but they are of uncertain coverage or consistency and have not been aggregated for national reporting. Two indicators require additional refinement or other development before reporting is possible. Eight of the indicators are, or should be, reported on a regional basis.

After the following brief summaries of the findings and data availability for each indicator, the remainder of this chapter consists of the indicators themselves. Each indicator page offers a graphic representation of the available data, defines the indicator and explains why it is important, and describes either the available data or the gaps in those data.

Each of the indicators in this section focuses on some part of the overall “coasts and oceans” system: estuaries, bays, and the like; shorelines; waters within 25 miles of the coast; waters out to 200 miles; and combinations of these four components. See Table 5.1 for the reporting area for each indicator.

System Dimensions

Tracking changes in selected types of coastal land and water habitat is important for understanding the goods and services that this system can provide. There are two basic indicators of coastal system dimensions. The first tracks the changes in area of such key habitat types as coastal wetlands, coral reefs, and seagrasses; the second focuses on the nature of the shoreline itself—beach, wetlands, cliff, bulkhead, and so on.

• What is the area of coastal wetlands, coral reefs, seagrasses, and shellfish beds? These features are key habitat for many species of crabs, fish, and seabirds, as well as for the smaller creatures that serve as food for these larger animals. These habitats are unique in that they are created by living (or once-living) organisms, such as mangrove trees and coral. From the mid-1950s to the mid- 1990s, wetland acreage on the Atlantic and Gulf coasts declined by about 400,000 acres, or about 8%, with the rate of loss slowing in the 1990s. Data are not adequate for national reporting on wetlands in other regions or on seagrasses, shellfish beds, or coral reefs.