Geoscience Reference
In-Depth Information
and density observed across the delta is para-
doxical to the surrounding Kalahari Desert, one
of the driest places on Earth. Angola, Namibia
and Botswana share the waters of the Oka-
vango and use OKACOM, a multilateral institu-
tion, to provide coordinated conservation and
management strategies and mediate resource
conl icts.
The Pantanal, which is nourished by precipi-
tation and the l oodwaters of the Paraguay
River, is shared by Bolivia, Brazil and Paraguay.
The wetlands comprise a diverse mosaic of
habitat types based on soil characteristics and
inundation patterns. The l ood-pulse system,
dependent on rainfall in the upper Paraguay
Basin and highlands and plateaus of Brazil, is
a key driver of life across the Pantanal. Flora
and fauna life cycles are synchronized with the
l ood and have adapted to distinct aquatic and
terrestrial phases. Human activity across the
Pantanal accelerated with the introduction of
cattle ranching during the nineteenth century.
Today, commercial-scale agricultural develop-
ment, expanding urbanization, and related activ-
ities threaten the integrity of this ecosystem.
On the United States Gulf of Mexico coast,
the Florida Everglades is a vast expanse of wet
sawgrass prairie that extends from Lake Okee-
chobee in south-central Florida to the man-
groves along the coast of southern Florida. It
was once among the world's largest fresh-water
marsh systems and still contains the biggest
contiguous tract of mangrove swamp in the sub-
tropics. The delta of the Mississippi River is the
end point of one of the world's largest terrestrial
drainage basins, where inland fresh-water
systems intergrade with the marine environ-
ment. Coastal Louisiana and the delta are losing
ground to the sea due to a combination of
factors, including eustatic rise in sea level, com-
paction of delta sediment, frequent hurricanes,
retention of sediment in upstream reservoirs,
conversion of wetlands for agriculture, and pro-
duction of oil and gas. Padre Island and Laguna
Madre are the longest such barrier island and
lagoon system in the United States. Substantial
portions of these U.S. Gulf sites are protected
in a national park, seashore, and several wildlife
refuges as well as state parks and private nature
reserves. However, many other portions of the
coast have been heavily developed and altered
by human activities often with deleterious
impacts on coastal processes and wetland
environments.
