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Invasive Species Management

The U.S. Army Corps of Engineers (USACE) is the steward of 12 million acres of public lands and waters at hundreds of water resources projects nationwide. In the efforts to conserve, protect and restore these lands and waters it is necessary to manage and control invasive species. Invasive species can be plants, animals and other organisms. They threaten our nation’s natural resources; seriously hinder navigation; adversely affect flood risk management, hydropower generation and water supply; and limit recreation use by the public.

To manage the threat of these species, USACE employs the latest economically efficient technologies and research; and biological, mechanical and chemical control methods. USACE also stays on the leading edge of invasive species management by developing new pest control techniques through its Aquatic Nuisance Species Research Program and Aquatic Plant Control Research Program. These efforts and the development of bio-control agents, new use patterns for aquatic pesticides, barrier systems, and innovative pesticide application techniques by USACE researchers and their partners are making a difference in the fight against invasive aquatic species nationwide.

Due to ever-changing ecosystems and the emergence of new and spreading species, the monitoring and management of invasive species will remain a continuous challenge for USACE and its partners.

Celebrate National Invasive Species Awareness Week! 

Identifying Invasive Species

Click the images below to learn more about problematic invasive species found on Corps lands.

 Burmese Python
Image of burmese python

Burmese pythons can grow to be one of the five largest snakes in the world and are currently wreaking havoc in the Everglades, preying upon native species and disrupting the ecosystem. Burmese pythons were originally introduced through the pet trades, so it is important that pet owners secure snakes and do not release them in the wild.


 Emerald Ash Borer
Image of emerald ash borer

Emerald ash borer infestations can devastate urban and natural forests in a very short time period by cutting off nutrient supplies. The emerald ash borer is already established in the northeastern U.S. and its distribution is moving across the Midwest. Closely monitoring firewood movement in quarantined areas is essential to controlling its spread.


 Feral Pig
Image of feral pig

Feral pigs can cause severe damage to crops, forests, and rangelands through their intensive rooting behavior. Feral pigs are found across the southeastern U.S. and California and their spread is attributed to free-ranging practices that persisted until the mid-20th century. Electric or strong mesh fencing may be a way to reduce further damage to property.


Image of hydrilla

Hydrilla is considered one of the most problematic species of aquatic plants to both fish and wildlife habitat and to recreation. Areas most affected include the southeastern U.S. and several West Coast states. Boaters should take care to clean hydrilla off vessels, especially if they plan to travel between water bodies.


 Japanese Knotweed
Image of japanese knotweed

Japanese knotweed is a terrestrial plant that quickly crowds out native species, especially near lakes and streams. Originally introduced as an ornamental, the Japanese knotweed now occupies areas within the eastern U.S. and the Midwest. Gardeners should be familiar with invasive plant species and request only non-invasive plants from nurseries and garden centers.


 Silver Carp
Image of silver carp

Silver carps out-compete native fish populations for resources and will likely overwhelm a profitable fishing industry if allowed into the Great Lakes. Currently, silver carps are found in the Mississippi River and its major tributaries as far north as Minnesota. Promoting silver carp as a food source may be a measure to prevent its future spread.


 Zebra Mussel
Image of zebra mussel

Zebra mussels are small freshwater mussels that attach to virtually any hard surface and pervade the Great Lakes and Mississippi River basins and some small lakes in the southwestern U.S. They cause both economic and ecological harm and cost millions of dollars annually to control. It is important for recreational boaters to keep their boats clean to prevent further spread of this species.




The Burmese python, one of the five largest snakes in the world, is native to a large variation of tropic and sub-tropic areas of Southern- and Southeast Asia, but is considered an invasive species within Florida and other areas of the U.S.
The Invasion Curve illustrates that prevention is the most efficient and least costly method of combating invasive species. As a non-native species becomes more established over time, the effort and associated costs of addressing it escalate exponentially. (From the USDA Forest Service 2005 Invasive Plant Environmental Impact Statement)