Global Change - Environmental Science - page 197

snow, the acidity of the water can have damaging effects on plants and the environment. Acid rain can destroy
leaves on plants (reducing photosynthesis) and trees, and can harm animals, fish, and other wildlife. When acid
rain penetrates into the soil, it can change soil chemistry, making it unfit for many living things that rely on soil
as a habitat or for nutrition. Acidified soil can leach out nutrients that plants need for their development,
growth, or maintenance. Plants exposed to pollutants can deteriorate from disease and insect infiltration.
Light pollution (luminous pollution) is excessive artificial lighting of the type often seen in any major indus-
trialized city. This artificial lighting interferes with animal species that depend on natural lighting phenomena
(such as the stars and moon) to find their way in the night. Lights may interfere with mating and nesting of spe-
cies, migration patterns, and hunting for food. In some satellite photos of sections of the Earth at night, it is dif-
ficult to identify specific cities due to the overall glow of light pollution—especially in Europe, the east and
west coasts of the United States, Japan, China, and India.
Noise pollution is another pollutant that is especially prevalent in urban areas. Noise pollution adversely af-
fects the health and lives of millions of people and is related to sleep disruption, hearing loss, high blood pres-
sure, and stress-related illnesses. The constant drone of vehicles on the roads, the flight of airplanes in and out
of airports, manufacturers, power plants, and others man-made sources produce noises that can impair animal
species. In animals, noise can cause stress, alter the delicate balance of detection and avoidance of predators
and prey, and interfere with animals' use of sounds in communication and reproduction.
Genetic pollution is a term popularized by environmentalist Jeremy Rifkin in his 1998 book The Biotech Cen-
tury. Biologists have used the term to describe the flow of genes from two genetically distinct organisms res-
ulting in a genetically modified organism (GMO). For example, the flow of genes from domestic, feral, non-
native, and invasive species into wild, native species. Today, the term genetic pollution is associated with the
genetic exchange of undesirable genes from GMOs to wild native species. In addition, genetic pollution often
refers to crops and aquaculture. Several GMO animal products have been developed, but none has yet been ap-
proved for market by the U.S. Food and Drug Administration (FDA).
Losses Due to Introduced Species
Introduced species originate in one location and end up in another, either by chance or by human intervention.
There are several words used to describe introduced species including nonnative, invasive, alien, and exotic .
There are more than 4,500 nonnative species in North America. Invasive species infest an area and can do
harm to it. They may kill other species, drive them out of the area, or cause economic damage for humans.
Examples of invasive species include kudzu, zebra mussels, the Mediterranean fruit fly, and sudden oak death.
The spread of invasive species has caused widespread damage to native habitats, including the elimination of
native species. Invasive species have interfered with crop production, causing losses of crops and money.
There are many ways an invasive species can be transported to new areas. Some are left over from farming and
animal raising (such as feral pigs), others arrive by accident (for example, the zebra mussel in the ballast water
of ships), and some are introduced intentionally to provide a service but then grow out of control (such as
kudzu in the southeastern United States and cane toads in Australia). Their adverse effects are many. The zebra
mussel can clog the openings to water intakes for water filtration plants. Kudzu, sometimes referred to as "the
vine that ate the South," was planted along freeways to prevent erosion. Unfortunately, kudzu can grow up to 3
feet in a single day, and since there are no known organisms that keep kudzu in check in its invasive habitat, it
has grown rampant. Invasive species' case studies are further discussed in Appendix B.
Losses Due to Endangered and Extinct Species