Environmental Engineering Reference
In-Depth Information
grasslands include the prairie in the United States, the pampas in Argentina, the steppes of Eurasia, and the
veldt in Africa. Less than 1 percent of the original prairie is left in the United States.
Pollution of land and water also can result in habitat destruction. And this destruction is not limited to the areas
in which pollution first occurs. For example, cities have storm drains that collect pollutants from a variety of
sources, including oils and other fluids from cars; feces from pets; fertilizers from our yards, playing fields,
and golf courses; and trash such as plastic bottles and bags. These pollutants flow downstream to the oceans,
destroying habitats and harming species along the way.
Historically, the lack of development in the majority of the Earth's tropical biomes has kept them relatively safe
from habitat destruction (in comparison with the greater habitat destruction born of development in temperate
biomes in the United States, Canada, most of Europe, Japan, and elsewhere). However, the recent increase in
development in tropical biomes has resulted in the accelerated habitat destruction in these regions.
Island species are especially vulnerable, because they have no place to go when their habitat is destroyed, de-
graded, or fragmented, and many face extinction as the island is developed. Many of those species are endemic
to their island (meaning, they are found nowhere else on Earth).
Maintenance through Conservation
As described in Sustaining the Earth: An Integrated Approach, by G. Tyler Miller and Scott Spoolman, there
are two major approaches to maintaining and protecting wildlife:
Species approach: Protecting individual endangered species, usually by laws and international treaties,
or by establishing breeding programs to help sustain these species and reintroducing them back into the
wild. The California condor is a good example of this approach.
Ecosystem approach: Increasingly, scientists and conservationists are finding that the best way to pre-
serve species is to preserve the ecosystem they inhabit. The ecosystem approach employs a four-point
plan:
• Locate and map the ecosystem. Develop an inventory of its species and the role they play in the eco-
system.
• Protect the most endangered ecosystems and their species.
• Repair degraded ecosystems.
• Design biodiversity-friendly developments that help protect endangered ecosystems.
One place this ecosystem approach has been especially effective is on California's Santa Cruz Island, within
Channel Islands National Park. On Santa Cruz Island, two native species were close to extinction. But instead
of working directly to increase these species through breeding or species-specific protection, conservation ef-
forts focused on returning the environment to conditions in which these endangered species formerly thrived.
On Santa Cruz Island, the introduced golden eagle had decimated the rodent population on which the endemic
Channel Island fox depended for survival. Conservationists reintroduced the bald eagle, which had become
nearly extinct on the island due to the historic use of DDT as a pesticide. The bald eagle greatly displaced the
invasive golden eagles, allowing rodent and, thus, fox populations to rebound. Additionally, conservationists
worked to eradicate the island's introduced and invasive wild pig population, which had been decimating both
plant and terrestrial animal populations. It took 26 months to eradicate the introduced wild pigs on the island,
but after focusing on habitat and restoring native species while eradicating invasive ones, the ecosystem of
Santa Cruz Island was overwhelmingly restored.
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