Geoscience Reference
In-Depth Information
220
200
180
160
140
120
100
80
60
40
20
0
Rest of Texas
Padre Island NS
2000
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Figure 15-33.
Number of Kemp's Ridley sea turtle nests found on Texas beaches, 2000-2010. Padre Island National
Seashore accounts for more than half of the nests, which reached totals of nearly 200 in 2008 and 2009. Adapted
from Padre Island (2010a).
turtles in the Gulf of Mexico (Padre Island
2010a). Historically these turtles laid eggs on
beaches stretching from Mustang Island, Texas
to Veracruz, Mexico. The primary nesting beach
was near the village of Rancho Nuevo in Tama-
ulipas, Mexico. As recently as 1947 about 40,000
females laid eggs there, and Mexico began pro-
tecting this site in the 1960s from egg and meat
poachers (Brown and Huey 1991). However,
turtle numbers had plummeted to about 200 by
1977. The United States and Mexico joined
efforts in 1978 to revive the Kemp's Ridley sea
turtle. A designated beach in the Padre Island
National Seashore was established for trans-
planting turtle eggs from Mexico each year as a
safeguard against extinction. Hatchlings are col-
lected and taken to an incubation facility at the
national seashore, and then released from the
beach when they reach appropriate behavioral
development (Padre Island 2010b). After more
than three decades of effort, the number of
nests began to increase markedly in the i rst
decade of the twenty-i rst century (Fig. 15-33).
This international cooperation has led to nascent
recovery for the Kemp's Ridley sea turtle in both
Mexico and Texas.
are tropical or subtropical with high average
summer temperatures and distinct dry and wet
seasons. Rainfall and annual l ood patterns play
a signii cant and inl uential role in molding the
ecosystem characteristics of these wetlands.
Each of the wetlands considered in this chapter
is of global consequence in terms of its biodi-
versity, functional and resource contributions.
Moreover, three of the four regions considered
include wetlands that span across country
borders
-
complicating issues of conservation
and protection.
The Sundarbans contains the world's largest
contiguous mangrove swamps, providing essen-
tial l ood and storm protection services for the
densely populated Ganges-Brahmaputra delta
region of India and Bangladesh. The mangroves
fuli ll important carbon sequestration and nutri-
ent cycling functions, as well as providing a
habitat for a diversity of l ora and fauna. More-
over, they also provide a home to the endan-
gered Royal Bengal tiger. The Okavango Delta
provides a life-sustaining resource to what
would otherwise be a dry subtropical desert.
Dependent on precipitation in the Angolan
highlands more than 1000 km from the delta,
the Okavango River transports water to the
inland delta during the driest and most critical
time of year. This l ood pulse supports an
immense diversity of life resident to the region
as well as migratory species that depend on its
waters for survival. The high species richness
15.6 Summary
This chapter provides wetland case studies from
across the low latitudes. Climatic conditions
