Invasive species are non-native plants, animals, and other living organisms that thrive in areas where they don’t naturally live. The U.S. Fish and Wildlife Service is the only agency in the federal government whose primary responsibility is the conservation of the nation’s fish, wildlife, and plants. Team up with us to take down invaders across the nation and help protect our public lands and waters!
Invasive species cause tremendous harm to our environment, our economy, and our health. They can drive out and eat native plants and wildlife, spread diseases, and damage infrastructure. Check out our aquatic invasive species least wanted list.
Many invasive species are spread or introduced into a new ecosystem accidentally. Some introduced species are brought in as pets or decorative displays and then escape or are released into the wild. Many invasive species thrive because they outcompete native species for food.
During National Invasive Species Awareness Week, we bring you some of the notorious and maybe less known top invaders:
Invasive zebra mussels have been found in “moss balls,” plant products sold at aquarium and pet supply stores, garden centers, florist shops, and online retailers. Zebra mussels are regarded as one of the most destructive invasive species in North America. They filter out algae and plankton that native species need for food, and they attach to and incapacitate native mussels. If you recently purchased a moss ball, we recommend you take steps to destroy, dispose, and drain. Destroy! Don’t Dump!
Non-native magnificent bryozoan are colonial invertebrates found in freshwater environments. That means they form colonies that attach to submerged trees and stones. Those colonies are jelly-like green blobs on underwater vegetation, branches, and other structures. They can clog water pipes, filters, and drains and compete with native with other aquatic species for food and space. Watch attack of the blobs.
Nutria are South American semi-aquatic rodents that live in colonies along rivers, lakes, and wetlands. They were introduced between 1899 and 1930 through the fur industry and over the years escaped or were intentionally released from captive populations. Nutria breed year-round and can give birth to two to three litters of four to nine young, allowing their populations to grow rapidly. This species is highly invasive and poses a serious threat to water infrastructure, agricultural crops, and wetland habitats.
The spotted lanternfly is an invasive insect with a healthy appetite for plants, and it can be a significant nuisance. This pest feeds on sap from economically important fruit crops, grapevines, trees, and plants, causing extensive damage. They lay eggs on almost any surface, including vehicles such as rail cars and trailers, as well as outdoor equipment and patio furniture, and can be easily spread by people.
We and our federal and state partners are on the front line fighting bighead, silver, black, and grass carp. They are voracious filter feeders, eating up to 40% of their body weight in a day. This aggressive feeding can radically alter ecosystems and reduce food sources for native fish. The spread of carp threatens our aquatic biodiversity and local outdoor economies.
The spread of invasive plants such as spotted knapweed has quickly become one of the largest threats to native prairies and grasslands that provide critical nesting habitat for a myriad of birds, mammals, plants, and pollinators. It is an aggressive weed that has overrun vast areas displacing native vegetation and reducing the forage potential for wildlife and livestock.
European Green Crab
The aggressive European green crab has already invaded the Atlantic Coast, damaging coastal ecosystems and collapsing the soft-shell clam industry in Maine. The green crab is also an intermediate host to a marine worm that can harm the health of local shorebirds. Recently discovered along the Pacific Coast, the crab could have huge economic and ecological impacts if it takes hold.
The Burmese python is a large nonvenomous constrictor found across south Florida where it represents a threat to native wildlife. Other creatures gaining a foothold in Florida include the Cuban treefrog, Nile monitor lizard, and various species of tegu lizards and chameleons. Some were released and some escaped. These aliens can disrupt an area’s food chain and prey on endangered animals and native plants.
Join us and our partners in the fight against invasive species to protect healthy, non-infested ecosystems. There are simple steps you can take to prevent the introduction and spread of invasive species:
- Remove plants, seeds, animals, and mud from boots, pets, gear, and vehicles before and after exploring.
- Check all your gear. Non-native seeds can stick to the bottom of your pack, the cuffs of your pants, or your animal’s fur.
- Stay on designated trails and roads to reduce disturbance and minimize contact with invasive plants. Do not camp or travel through areas infested with invasive plants.
- Do not release unwanted pets or dump the contents of an unwanted aquarium into the wild. In most states it is illegal.
- Use certified or local firewood and hay.
- Stop aquatic hitchhikers! Clean and drain your boat and gear before leaving a site.
- Keep the adventure and leave the invasive species. PlayCleanGo!
Some non-native species don’t cause harm and they are not considered invasive. They may not prevent the survival of others within the ecosystem. We actively manage those non-native species that do cause harm.
We have Invasive Species Strike Teams working to protect national wildlife refuges, national fish hatcheries, and public lands across the United States. These teams respond rapidly to new infestations, provide education, and offer technical expertise.
Invasive species are a primary cause of global biodiversity loss. They threaten nearly half of the imperiled species in the United States and have contributed to more than 40% of the current listings under the Endangered Species Act.
Invasive species impact everyone. In the United States, invasive species cause an estimated $123 billion dollars in damage and costs every year to agriculture, public health, hydropower facilities, municipal water supplies, and the aquaculture industry. More than 6,500 non-native species have established their home here.
Through education and prevention, we can stop the spread of invasive species in the nation’s lands, waterways, and everything in between!
Written by Vanessa Kauffman, public affairs specialist, U.S. Fish and Wildlife Service (USFWS) headquarters.
Contributors: Holly Richards, fish enthusiast with the branch of communications and partnerships, USFWS Fisheries and Aquatic Conservation and John Klavitter, national coordinator for invasive species, island restoration, and cooperative recovery initiative, USFWS National Wildlife Refuge System.