 
A biological invasion is taking over our national parks. Invasive species, plants
and animals not native to a region, are spreading across the country at an
alarming rate. While the northern
snakehead fish garnered national media attention, thousands more invasive species
have been wreaking havoc to our environment,
virtually undetected by the public at large.
Also called aliens, non-natives, or exotics, invasive species haven't arrived on their own. They have all been transported as a result of, or deliberately for, some form of human activity, smuggling themselves aboard cargo ships and airplanes or transplanted for commercial purposes.
Once an invasive species is introduced to a new environment, it will rapidly take hold and spread throughout its new home, with no natural predators to deter its population growth. Invasives will eat or pollute native food supplies, take over shelter and breeding areas, or crowd out habitat, eventually wiping out native populations and disrupting native ecosystems and species that have evolved in harmony for thousands of years.
Invasive species are present in nearly 200 of our national parks and wildlife refuges, from Great Smoky Mountains to Hawaii's Volcanoes and Haleakala National Parks.
Let's take a look at some examples of these invading plants, insects, and animals:
- In the Everglades, native fish populations are being decimated by the introduction of Asian swamp eels, and native plants are being smothered by the invasive climbing fern.
- Native trees and entire forests in several national parks, including Great Smoky Mountains and Glacier National Parks, are falling victim to introduced insects and diseases.
- In Yellowstone National Park, invasive lake trout have successfully killed off most native cutthroat trout species in many of the park's lakes and streams. Grizzly bears, which rely on native trout as a seasonal food choice, are unable to consume the nonnative trout because they swim at greater depths.
Invasive species are spread mainly by human activities, so our best shot at limiting their impact is an educated public.
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Make a Difference! |
- Create a Native Garden. Educate yourself on the plant species indigenous to your area. When gardening, be sure to use native plants. And be particularly careful to avoid invasive plants such as Japanese honeysuckle, English ivy, bamboo and purple loosestrife.
- Learn to identify invasive plants and be sure to remove them from your yard.
- Travel Light. When you travel—whether it be across the ocean or across the state line—be sure to clean your shoes before and after your visit, because seeds, spores, bugs, and viruses can easily be transported in this way. If you drive to a national park, be sure to scrub your tires too.
- Do not transport animals, reptiles, amphibians, or plants into locations where they are not native.
- Never release exotic animals into the wild. Your good intentions could have devastating and far-reaching consequences. If you are considering buying an exotic species, don't! The exotic pet industry is typically harmful to both exotic and native species.
- Do not ship or carry nonnative plants, because they may carry bugs, eggs, or seeds.
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