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Review the indicators
at a glance
The coasts and oceans of the United States extend from the narrow
ribbon of shoreline that defines the waters 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 Californiaall 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 Americas
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 itselfbeach, 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.
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