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PROPOSED
MEASURES: EXTENT & HABITAT
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The area occupied
by five key habitat types, for each major region of the U.S. coast.
Each habitat type supports a different variety of plants and animals
and human uses, and each region has a characteristic assortment of key
habitat types. (Fig. 1, 2, 3)
The degree
of erosion of coastal lands. Erosion can result in significant changes
in the amount and type of coastal land area, with both ecological and
human consequences. (Fig. 4)
Changes in wetland
area from 1985 to 1995 were fairly small; most conversions of coastal
wetlands occurred prior to this reporting period. From the 1950s to
the 1990s, an estimated 14 percent of coastal wetlands were lost, but
data are not available to quantify long-term coastal wetlands losses.
| Area
of Key Habitat Types (1) |
| Northeast |
Southeast
& Gulf |
Northwest |
Southwest |
Alaska |
Great
Lakes |
Pacific
Islands |
| shellbeds |
shellbeds |
deep
sandy bottom |
beaches |
beaches |
shellbeds |
native
mangrove forest |
| mudflats |
mangrove
forest |
mud
flats |
shellbeds |
deep
sandy bottom |
deep
sandy bottom |
beaches |
| intertidal
zone |
coral |
intertidal
zone |
intertidal
zone |
deep
silty bottom |
deep
silty bottom |
coral |
| underwater
grasses |
underwater
grasses |
kelp
beds |
kelp
beds |
intertidal
zone |
underwater
grasses |
| wetlands |
wetlands |
wetlands |
wetlands |
wetlands |
wetlands |
| Source:
The Heinz Center |
This table presents
five key habitat types for each of the major regions of the U.S. coast,
based on the area they occupy and their importance in regional ecosystems.
Environments such as beaches, wetlands, rocky or sandy areas between
high and low tide, coral reefs, mangroves, and mud or rocky bottom areas
serve as habitat for animals and plants and delight many people as well.
Full reporting would include the area occupied by each habitat type,
as well as trends beginning with historical data, for each region. Information
on changes in coastal wetland area nationally, and in seagrass area
in the Gulf of Mexico, is provided as an example.
Example:
Seagrass Status and Trends,
Gulf of Mexico (2) Technical
Note |
Coastal
Wetlands Loss, 1985- 1995 (3)
Technical
Note |
Source: U.S.
Geological Survey, Biological Resources Division |
 |
| |
Source:
U.S. Fish and Wildlife Service, National Wetlands Inventory |
| Coastal
Erosion (4) Technical
Note |
|
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Coastal
Land Loss
Many stretches
of the U.S. shoreline are eroding, in part because of a combination
of rising sea levels and sinking of adjacent coastal lands. Erosion
can lead to the loss of ecologically important coastal habitat,
as well as damage to coastal structures. The data shown here are
from a one-time historical study.
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| Source:
U.S. Geological Survey |
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STATUS
OF DATA & OTHER NOTES
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No consistent
and comprehensive national information is available to report
on the area and change in key habitat types, with the exception
of coastal wetlands, which are reported under the U.S. Fish and
Wildlife Service’s National Wetlands Inventory (NWI). However,
NWI information is provided on a national, not regional, basis.
Data on seagrasses are from a review of multiple previous efforts
and are presented here as an example.
No consistent
and comprehensive national information is available to report
on coastal erosion rates.
Under international
law, the United States has designated an area up to 200 miles
from its shores as an exclusive economic zone (EEZ), in which
it exercises control over fishing, mining, oil and gas development,
and many other activities. The map of protected areas, on pages
61- 62, shows the approximate boundary of the EEZ associated
with the continental United States. When combined with those parts
of the EEZ associated with Alaska, Hawaii, and other Pacific islands,
the U.S. EEZ encompasses an area larger than the continental United
States.
Please see
the Technical
Notes for additional information.
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