CONCEPT 11-4 267
THINKING ABOUT
Wetlands Mitigation
Should a new wetland be created and evaluated before any-
one is allowed to destroy the wetland it is supposed to re-
place? Explain.Wetlands restoration is becoming a big business.
While some wetlands restoration projects have failed,
others have been very successful (Figure 11-13 and In-
dividuals Matter, at left).
RESEARCH FRONTIER
Evaluating ecological services provided by wetlands, human
impacts on wetlands, and how to preserve and restore wet-
lands. See academic.cengage.com/biology/miller.A good example of an attempt to restore a once vast
wetland is that of the Everglades in the U.S. state of
Florida, as described in the following case study.
■ CASE STUDY
Can We Restore the Florida
Everglades?
South Florida’s Everglades (USA) was once a 100-kilo-
meter-wide (60-mile-wide), knee-deep sheet of water
flowing slowly south from Lake Okeechobee to Florida
Bay (Figure 11-14, p. 268). As this shallow body of
water—known as the “River of Grass”—trickled south
it created a vast network of wetlands with a variety of
wildlife habitats.
Since 1948, a massive water control project has pro-
vided south Florida’s rapidly growing population with
a reliable water supply and flood protection. But is has
also contributed to widespread degradation of the origi-
nal Everglades ecosystem.
Much of the original Everglades has been drained,
diverted, paved over, ravaged by nutrient pollution
from agriculture, and invaded by a number of plant
species. As a result, the Everglades is now less than half
its original size. Much of it has also dried out, leaving
large areas vulnerable to summer wildfires. And much
of its biodiversity has been lost because of reduced wa-
ter flows, invasive species, and habitat loss and frag-
mentation from urbanization.
Between 1962 and 1971, the U.S. Army Corps of
Engineers transformed the wandering 166-kilometer-
long (103-mile-long) Kissimmee River (Figure 11-14,
p. 268) into a straight 84-kilometer (56-mile) canal
flowing into Lake Okeechobee. The canal provided
flood control by speeding the flow of water but it
drained large wetlands north of Lake Okeechobee,
which farmers then turned into cow pastures.
To help preserve the wilderness in the lower end of
the Everglades system, in 1947, the U.S. government
established Everglades National Park, which contains
about a fifth of the remaining Everglades. But this pro-
tection effort did not work—as conservationists had
predicted—because the massive water distribution and
land development project to the north cut off much of
the water flow needed to sustain the park’s wildlife.
As a result, 90% of the park’s wading birds have
vanished, and populations of other vertebrates, from
deer to turtles, are down 75–95%. Florida Bay, south
of the Everglades is a shallow estuary with many tiny
islands, or keys. Large volumes of freshwater that onceFigure 11-13Natural capital
restoration: wetland restoration
at Fort Erie, Ontario, Canada before
(right) and after (left).Niagara Peninsula Conservation AuthorityNiagara Peninsula Conservation Authority