What are aquatic invasive species?
Aquatic animals and plants are totally dependent on aquatic ecosystems for at least a portion of their life cycle. Species that are not native to an area are sometimes referred to as exotic, alien or non-indigenous species.
If the species has been moved to a new area as a result of human activity, it can also be called an introduced species and if the species is having a harmful effect on the new environment, local economies or human health it is termed an invasive species.
Invasive species bypass natural barriers that would otherwise prevent their migration to new areas. The Southwestern United States has the largest number of aquatic invasive species in the nation. Worldwide trade growth has been significant in the region. Coastal population growth has also been significant resulting in increased recreational use.
While may communities depend on many intentionally introduced plants and animals for food and industry, invasive species are economically expensive to control. Invasive species foul up waterways, affect water supplies, irrigation, water treatment, aquaculture, fisheries, tourism and shipping.
Invasive species cost the U.S. about $120 billion per year in environmental damage and loss. Management of invasive species is dependent on the public's understanding and acceptance of the actions needed to protect the environment's valuable resources. Monitoring is a critical component of an effective Early Detection & Rapid Response Management Plan.
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How do they spread?
Worldwide trade growth and coastal population growth both represent an increased threat of additional species introductions and spread through the following pathways:
- "Hitchhiking" by plants and animals on boat hulls, fishing gear and trailers
- "Hitchhiking" by invasive plants and animals that may be attached to noninvasive plants and animals ordered for aquaria, water gardens or landscaping - or in the water or media in which noninvasive plants are shipped
- releasing of aquarium contents and aquatic pets
- mishandling of non-native species by research or educational facilities
- transporting non-native species through aquaculture, live bait and seafood industries
- intentionally introducing species for food sources or to control other populations
- discharging of ballast water from commercial tankers on trans-ocean voyages.
What do they threaten?
Invasive species threaten natural resources and biodiversity in terms of competition for food and space, predation, pathogens and parasites.
They are the second cause of species extinction after habitat destruction. About 42% of the species on the Federal Threatened or Endangered species lists are at risk primarily because of invasive species. Invasive species degrade natural habitats, displace native species, and cost billions of dollars annually in control treatments and lost productivity.
It is almost impossible to eradicate an aquatic invasive species completely. However, if detected early enough and if locally confined, there is some possibility of success. The State of Georgia has established an Aquatic Species Invasive Species Management Plan.