Last updated on Thursday, September 29, 2011 http://water.epa.gov/type/oceb/habitat/invasive_species_index.cfm

Water: Habitat Protection 

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Invasive Species 

 

Invasive species means an alien species whose introduction does or is likely to cause economic or 

environmental harm or harm to human health. Invasive species are one of the largest threats to our 

terrestrial, coastal and freshwater ecosystems, as well as being a major global concern. Invasive 

species can affect aquatic ecosystems directly or by affecting the land in ways that harm aquatic 

ecosystems. Invasive species represent the second leading cause of species extinction and loss of 

biodiversity in aquatic environments worldwide. They also result in considerable economic effects 

through direct economic losses and management/control costs, while dramatically altering ecosystems 

supporting commercial and recreational activities. Effects on aquatic ecosystems result in decreased 

native populations, modified water tables, changes in run-off dynamics and fire frequency, among 

other alterations. These ecological changes in turn impact many recreational and commercial activities 

dependent on aquatic ecosystems. Common sources of aquatic invasive species introduction include 

ballast water, hull fouling, aquaculture escapes, and accidental and/or intentional introductions, among 

others. 

 Pathways for Species Introduction 

 Useful Links to Invasive Species Information

Vessels and Invasive Species 

Vessels can be a significant pathway for the introduction or spread of 

invasive species through the discharge of ballast water containing invasive 

species or the transport of invasive species that have accumulated as 

biofouling on ships' hulls. EPA and its federal partners, such as the U.S. 

Coast Guard, are working together and using their authorities to help 

address the environmental and economic threats associated with shiprelated introductions of invasive species. For information on EPA activities under the Clean Water Act 

addressing this issue visit the EPA Vessel Discharges, and EPA Clean Boating Act webpages. For 

information on U.S. Coast Guard activities under their statutory authorities, visit the U.S. Coast Guard Aquatic Nuisance Species webpage. 

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Features 

Overview of EPA Authorities for Natural 

Resource Managers Developing Aquatic 

Invasive Species Rapid Response and 

Management Plans

Economic Impacts of Aquatic Invasive Species 

Workshop

Executive Order 13112 on Invasive Species

(PDF) (4 pp, 68 KB)

Ecological and Economic Impacts and Invasion 

Management Strategies for the European Green 

Crab (PDF) (73 pp, 826 KB)

Watershed Academy Web: Invasive NonNative Species

Purple Loosestrife. 

This beautiful plant is 

highly aggressive in 

the wild, displacing 

native vegetation. 

Corbicula fluminea. Often 

called the Asian clam, this 

small mollusk can clog intake 

pipes for cooling water. 

Invasive Species | Habitat Protection | US EPA Page 1 of 1

http://water.epa.gov/type/oceb/habitat/invasive_species_index.cfm 11/10/2011