Introduction

Invasive Species Defined

What's Being Done

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 National Invasive Species Information Center

 

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Submodule 9: Social Impacts

How Invasive Species can Change Our Lives

Invasive species can cause serious economic hardships, which in turn can cause serious social impacts. Regions that are highly dependent on particular species of plants and animals can be hard hit when these species become endangered, and invasive species often cause a decrease in populations of native species. For example, when yellow starthistle (Centaurea solstitialis) takes over widespread regions of California rangeland, it disrupts ranching because livestock won’t eat the weed. For this reason, the cost of raising livestock in infested areas has soared. The boll weevil (Anthonomus grandis) arrived in the U.S from Mexico in the late 1800s and spread to all cotton-growing regions by the 1920s. The insect eats many parts of the cotton plant and lays its eggs in the fruit, destroying it before the cotton boll can form. The boll weevil’s invasion greatly increased the cost of cotton production and caused hardships for millions of people. On a positive note, devastation of the cotton-growing industry by this insect lead to the diversification of farming in the south. It was during this time that peanut growing was introduced to southern U.S. farmers, breaking the region’s dependence on cotton for survival.

 

The invasion of non-indigenous species often leads to environmental degradation, which can result in negative impacts for humans. Many think of any degradation of the environment as harmful. There are many negative “quality of life” issues in which invasive species play a prominent role – for example:

 

Fishing: Aquatic invasive plants frequently alter native plant populations, leading to degradation of habitat for native fishes. Invasive fish and other aquatic animals can decrease numbers of native fish by feeding on them, or out-competing them for resources. In addition, invasive plants and animals can cloud water, change water flow patterns, and clog streams, thereby decreasing populations of sport fish. Some non-native fish are able to hybridize with native fish, causing the native fish to go extinct. Weeds growing along riverbanks can make access for fishing difficult. For those whose livelihood is in the sports fishing industry, invasive species can negatively impact income.

 

Boating: Mats of invasive water plants can become entangled in propellers making boating difficult or impossible. Water front properties lose value as boating become threatened due to invasive species.

 

Camping and hiking: Many invasive plants have thorns or spikes, making hiking unpleasant or impossible. Invasive plants can alter fire frequency, making certain areas more dangerous than in the past.

 

Tourism: Some areas of the county prized for their native wildflowers have experience a fall in the number of “eco-tourists” as fields of native flowers are overrun by weeds. In addition, plant infestations can lead to a drop in populations of sought-after wildlife as habitats are degraded.

 

Safety: There are several examples of native plants altering fire pattern. In some of these areas, wildfires have become common and are burning hotter. Every year deaths and injuries are reported from these fires.

 

Job opportunities: People employed at recreational areas degraded by invasive species often lose their jobs. Fishery workers in several areas of the country have lost their jobs due to decreased populations of native fish.

 

Cultural heritage: Invasive species can alter ecosystems to such a degree that native plants and animals become extinct. Communities build on and base their identities on plants and animals that provide their livelihood and recreation. Some communities have built their folklore around species that are now endangered or extinct.

 

 

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