U.S. Fish and Wildlife Service biologist holds a bighead carp. Photo by R. Hagerty, U.S. Fish and Wildlife Service.

Some are sharp, some are spotted and some are slithery, but all invasive species are bad for public lands. Invasive species are nonnative organisms whose introduction to a particular ecosystem can cause economic or environmental harm, or harm to human, animal, or plant health.

Some nonnative species don’t cause harm (They’re not “invasive”), but those that do can cost billions in damage and disrupt an environment’s natural balance.

No matter where they came from, how they got here or what harm they cause, invasive species are a serious concern for all who protect and preserve America’s public lands and waters.

Invasive Mussels

The quagga mussel is an invasive species that poses a substantial threat to water resources. Photo by S. Pucherelli, Bureau of Reclamation.

Quagga and zebra mussels are invasive species from Eurasia’s Caspian Sea. These tiny mollusks reproduce rapidly and attach to surfaces such as pipes, lake bottoms, docks, and break walls, forming a crust of shells. Infestations in dams and water treatment facilities can impact the delivery of water and power. Large colonies in lakes and waterways affect freshwater ecosystems, leading to harmful effects on native and endangered species, including recreational game fish. Mussel infestations may impact recreation in other ways, from sharp shell fragments scattered over beaches to increased requirements and cost for boat inspection and decontamination.

What are we doing to address invasive mussels?

Since their discovery in the Great Lakes in the 1980s, Interior’s bureaus and partners have worked to prevent, contain and control invasive mussels. Efforts to limit their spread include:

Watercraft inspection and decontamination

Monitoring

Rapid response

Public education

Research on detection and control measures

As of 2019, through collaboration with the Western Governors’ Association and federal, state and tribal agencies, we’ve also led numerous activities to protect western waters from the spread of invasive mussels.

Get Involved

Invasive mussels primarily spread by hitching rides on boats and other watercraft. Preventing the spread of invasive mussels starts with you! Remember to Clean, Drain and Dry your watercraft after leaving the water. With your help, we can protect the nation’s waterways and wildlife.

Rapid ʻŌhiʻa Death

ʻŌhiʻa is a native tree important to Hawaii ecology and culture that is at risk from a tree-killing fungus. Photo by R. Bartlett, U.S. Geological Survey.

ʻŌhiʻa -- the most abundant native tree in Hawai’i -- is both culturally significant and ecologically valuable. Sadly, ʻŌhiʻa are now threatened by two invasive fungal pathogens that cause Rapid ʻŌhiʻa Death (ROD), a serious threat to native forests in the Hawaiian Islands. Unfortunately, the future of the ʻŌhiʻa tree is in doubt. Hundreds of thousands of ʻōhiʻa have already died due to this fast-acting disease.

What are we doing to address Rapid ʻŌhiʻa Death?

Researchers are developing and refining techniques to quickly detect the presence and spread of ROD, while also addressing management challenges posed by this threat. The Office of Native Hawaiian Relations has sponsored the “‘Ōhiʻa Challenge,” a competition to help address the issue.

Get Involved

Whether living in or visiting the Hawaiian Islands, be aware of ROD and follow biosecurity protocols that are in place to reduce the spread of this disease. Learn more about ROD and help spread the word about the “‘Ōhiʻa Challenge” so that we can identify and support solutions.

Invasive Asian Carp: Bighead, Silver, Black and Grass Carp

Silver carp jumping during electrofishing in the Fox River. Photo by R. Hagerty, U.S Fish and Wildlife Service.

Finding their way into America’s rivers and lakes, Asian carp (bighead, silver, black and grass carp) threaten recreational, commercial and subsistence fisheries worth billions of dollars annually. These aquatic invaders take over habitat and threaten native species, and impact recreational boating and other activities important to the livelihood of many communities.

What are we doing to address Asian carp infestation?

Interior experts provide key leadership, research and tactical assistance across the Great Lakes, Upper Mississippi River and Ohio River basins. By developing the “Management and Control Plan for Bighead, Black, Grass, and Silver Carps in the United States,” we can use it as a national blueprint on the management of Asian carp. We’ve been developing critical new technologies to combat the threat posed by all Asian carp life stages (eggs, larvae, juveniles and adults) and working with natural resource managers to improve early detection and rapid response activities.

Get Involved

Everyone can play a role in preventing the spread of Asian carp. Ways you can help:

Learn to identify juvenile Asian carp

Only use wild-caught bait fish in waters where they came from

Don’t move live fish from one location to another

Drain lake or river water from live wells and bilges before moving your watercraft

Finally, become an ambassador for your watershed and help others learn how to help!

Invasive Rodents

Invasive house mice cause injury to nesting birds like this injured Laysan albatross at Midway Atoll National Wildlife Refuge. Photo by U.S. Fish and Wildlife Service.

Invasive rodents on islands cause serious impacts to both native biodiversity and infrastructure. These harmful rodents, such as mice and rats, prey upon and compete with native wildlife, reducing native biodiversity and sometimes leading to the extinction of a species. Rodents damage buildings by chewing through wood and insulation and gnawing on wiring which can trigger fires. Islands represent some of the greatest concentration of biodiversity, with island species often being evolutionarily distinctive. Unfortunately, these species are often highly vulnerable to novel disturbances, particularly invasive rodents.

What are we doing to address invasive rodents on islands?

Interior works with a variety of partners on invasive rodent prevention, management and eradication. The main goal is to prevent rodents from reaching new islands. Where already found, invasive rodents are trapped and killed to limit their impact on native species and infrastructure. Helicopter drops of rodenticide are used to completely eradicate rodents from islands. Successful rat eradications can lead to amazing native restoration stories. In 2011, rat eradication at Palmyra Atoll National Wildlife Refuge in the Pacific resulted in the native tree population increasing by 5,000 percent since rats were removed.

Get Involved

Whether you’re traveling or supporting island conservation, here are a few ways to help:

Prevent invasive rodents from reaching new islands (i.e., using rat guards on boat mooring lines)

Spread the word on how devastating rodents can be for native species on islands

Learn more about rat eradication and island restoration

Invasive Weeds

Spotted knapweed is an invasive plant that forms dense stands, decreasing native vegetation and degrading forage quality for wildlife. Efforts are underway to limit impacts and prevent the spread of knapweed and other invasive plants. Photo by Bureau of Land Management.

Today, noxious weeds and other invasive plant species infest more than 79 million acres of public lands, an increase of 44 percent since 2000. This presents multiple impacts to threatened ecosystems. For example, downy brome (cheatgrass), infests 50 million acres and provides fuel to wildfires that burn across increasingly larger areas. And in a devastating one-two punch, cheatgrass can quickly re-establish itself on burned lands, outcompeting native grasses and increasing the extent of infestation.

What are we doing to address invasive weeds in the West?

Interior is responsible for preventing and controlling invasive weeds on the lands that we manage. We prioritize invasive species projects -- protecting the most critical resources -- such as protecting stream corridors or greater sage-grouse critical habitat. We partner with numerous partners, such as through Cooperative Weed Management Areas (CWMA’s), that assist with inventory, treatments, monitoring and other project work.

Get Involved

Prevention is key, so identifying invasive plant species is crucial. Helping with early detection, rapid response and public awareness is also important. Report weed infestations to your local Interior bureau field offices and be involved in a local CWMA.

Preventing the Next Invasive Species

The invasion curve depicts that as time goes on, invasive species are more costly to manage. Graphic by S. Sparhawk, National Park Service.

Once an invasive species becomes established, it is rarely possible to eradicate. The best way to avoid the harm that invasive species can cause is to prevent them from entering the country.

We use several ways to predict species at risk of becoming invasive and then preventing them from being imported. By monitoring and inspecting wildlife imported into the United States at designated wildlife ports we can intercept problematic species.

Get Involved

You can be involved in prevention in various ways. Please keep your pets secure and do not release them - under any circumstances. Animals like exotic fish and reptiles can wreak havoc on native wildlife and habitat when they escape or are released. If you must surrender a pet because you can no longer care for it, do so responsibly -- see Don’t Let it Loose for pet rehoming options. Other excellent sources for how to prevent the spread of invasive species include:

Volunteer shows a kōlea lau nui plant freed from the invasive plant, Himalayan ginger. Photo by National Park Service.

The Power of Partnerships

Invasive species may be widespread and vastly different, but luckily so are the methods and teams protecting public lands. The Department of the Interior is forging strong partnerships with others to collectively address the threat of invasive species. We can’t do it alone. Together, success is possible!