Upwards of 50,000 invasive species have been introduced to the United States to date, threatening biodiversity and the longevity of ecosystems in everything from national parks and oceans to suburban backyards and creek beds. No invasive species is too small to do damage. Everything from vines and insects to birds and mammals can destroy fragile environments and utilize limited natural resources vital to the survival of native plants and animals.
Communities across the United States have fought to take action against invasives, sometimes creatively (and sometimes detrimentally) to protect the fragile ecosystems that are so integral to the world’s biodiversity. Researchers have observed mixed results from introducing additional new species to eradicate others or bringing in unsustainable and potentially fatal options like poisons for invasive species.
The inevitability of invasive integration—from released aquarium pets to “hitchhikers” on international shipping freighters—makes battling invasive species increasingly complex and challenging. Nevertheless, thousands of independent citizens, organizations, and businesses around the country are seeking out new ways to do just that.
Stacker mined studies, news reports, a variety of data sets, and even first-person accounts to find 20 examples of communities that are fighting invasive species without harming the native plants and animals. These methods require a certain amount of inventiveness, highlighted in this gallery as projects designed as eco-friendly that can serve as inspiration for other communities.
Read on to learn about a professional chef who’s turning invasive species into gourmet dishes, incentives for bringing rodents of unusual sizes to shore, and even an invasives-sniffing dog whose olfactory senses are helping eradicate intruding species in New York parks.
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The New York-New Jersey Trail Conference has taken the helm for regional work against invasive species, perhaps most notably with its Conservation Dogs program, launched in 2018. That program was inspired in part by a 2010 study published in Invasive Plant Science and Management. The study found that similarly to sniffing out bombs or missing people, dogs could be trained to identify invasive plants by scent. The star of that program is Dia, a labrador retriever whose training commenced with the identification of an invasive plant called Scotch broom (Cytisus scoparius) in Bear Mountain and Harriman state parks and has expanded to include an invasive grass called slender false brome (Brachypodiumsylvaticum) and invasive insect called spotted lanternfly. Having Dia—and not pesticides—do this work allows for a low-impact, 100% eco-friendly method for rooting out invasives.
Support the New York-New Jersey Trail Conference here.
The Arnold Arboretum at Harvard University has embarked on a three-year project that utilizes a Ukrainian moth called Hypenaopulenta to eat the invasive plant swallow-wort. Within weeks in a controlled space in June 2019, released moths had laid eggs and decimated the swallow-wort population.
Invasive vegetative species were estimated to occupy as much as 90% of biodiversity in a control area of Kaukauna, Wis., according to a representative of the 1000 Islands Environmental Center there. To combat the proliferation of said plants, the environmental center in the fall of 2018 deployed unusual heroes: goats.
The goats were found to have defoliated all the invasive species during their time at the nature center, prompting the organization to invite the goats back in June 2019 for another buffet of invasives. A third visit has been planned for the fall.
More than 1.5 million invasive, wild hogs live in Texas, according to Texas Parks and Wildlife, and reporting from Smithsonian shows the damage the animals have wrought throughout the southern U.S. The Wild Boar Company, based out of Hubbard, Texas, mitigates the feral hog explosion by purchasing living and dead wild boar as well as hosting hunting tournaments for area hunters. Meat is then resold to pet food companies.
Hunters and meat processors throughout the region see hunting wild boar as an eco-friendly, healthy alternative to Texas’ prior approval of leaving lethal doses of poison out for the hogs, which can in turn poison other animals that consume the poison or poisoned boar—not to mention poisons leaching into the soil and groundwater.
Asian carp—a catchall term for Chinese native fish bighead and silver carp—first appeared in the Mississippi River Basin in 1980. They didn’t arrive by accident. Fresh fish markets imported Asian carp as an affordable option. It didn’t take long for the fish to begin appearing throughout Illinois and Mississippi rivers. In some places, Asian carp comprise more than 95% of all living organisms and have now been counted in 12 states. The fish threaten to overtake the Great Lakes and fish populations throughout the U.S., which has spurred the Illinois Department of Natural Resources (DNR) to come up with a unique way to take on this invasive species.
“Carp cowboys” are a deployment of professional fishermen throughout Illinois hired by the state to round up carp from Illinois waterways. Because carp fetch less money than other species at the store (10 cents per pound versus 50 cents for other fish), the state is offering an additional 10 cents per pound of carp taken to fish markets or processors in a pilot program along the Lower Illinois River. A week of carp fishing can yield 60,000 pounds of fish; the program eventually seeks to lift up to 50 million pounds of Asian carp out of various Illinois water bodies each year and onto dinner plates.
The beautiful, prolific, venomous, and invasive lionfish has wreaked havoc on Atlantic waterways since the 1980s when it is believed they first were put there by aquarium owners or pet owners. Today, the fish—which are happy to consume over 70 varieties of other fish and even more invertebrate—can be found throughout South America and the Caribbean up through Massachusetts.
There has been no shortage of attempts to curtail the lionfish population, including the invention of lionfish-vacuuming robots and an event hosted by Reef Environmental Education Foundation (REEF), called the “Lionfish Derby Series” that seeks to capitalize on the flavor and fun organizers associate with hunting lionfish throughout Florida waters. Derby teams can sell some fish they catch, while others will be part of lionfish tastings, fillet workshops, dissection demonstrations, and other activities.
Learn more about REEF and support its work against invasive species here.
Green crabs arrived in Maine from Europe at the turn of the 20th century. But in recent years, a different lineage of green crabs has arrived from Nova Scotia, Canada, and decimated biodiversity throughout Maine’s bodies of water, most notably among species like eelgrass, lobster, clams, and mussel beds, according to research conducted by the Maine Clammers Association (MCA) and Downeast Institute. That study found predation rates that exceeded 99%.
In response, the MCA initiated the 5 to Stay Alive Trapping Program, which offers green crab traps to the public that are safe for fish and can help to mitigate the invasive green crab population. The MCA also designed the largest green crab fencing installation in all of Maine State in Casco Bay, which featured 3,000 feet of fencing to keep the crabs contained.
To support the Maine Clammers Association, click here.
An $800,000 grant from the California Department of Fish and Wildlife in 2015 went toward efforts by the Mountains Restoration Trust to complete eradicate red swamp crayfish (Procambarusclarkii) from the Malibu Creek Watershed.
These little freshwater crustaceans are believed to have shown up in Southern California waterways a century ago and have systematically squeezed out other, native species, like the declining Arroyo chub. One of the Mountains Restoration Trust’s flagship projects is the Crayfish Removal Open House, a series of free events in which the public is invited to come out and help trap and remove crayfish along the watershed, 100 yards at a time.
To learn more about Mountains Restoration Trust and support its efforts, click here.
The 2017 documentary “Rodents of Unusual Size” takes an in-depth look at one man’s war against a prolific invasive species in Louisiana: the nutria. The nutria is a semi-aquatic rodent native to South America and can grow to be about 20 pounds, subsisting only on marsh plants.
Nutria rodents were brought to the States in the 1930s to diversify skins sources for coats and hats. Various animal releases and escapes gave the mammals a foothold in the marshes of Louisiana, where a lack of natural predators has allowed the critters to eat their way through marshlands, creating erosion and expanded waterways that wreck coastal and marshy habitats. Various efforts to curtail the nutria population have been trotted out, the most significant being Louisiana’s 2002 launch of the Louisiana Coastwide Nutria Control Program, which offers payouts on each nutria killed. That rate increased for the 2019-2020 season, from $5 to $6—a difference in the thousands for some of the biggest nutria marksmen throughout the New Orleans and greater Louisiana coastal ways.
In Puerto Rico, many of the wild species seen regularly were introduced there under less-than-natural terms, such as a variety of cats and dogs and a variety of species of insects, reptiles, and birds. But no species have done the damage of the small Asian mongoose, which is responsible for as many as 70% of rabies cases in Puerto Rico. Small Asian mongooses are carnivorous members of the Herpestidae family, which includes meerkats. Mongooses are not rodents and were brought to islands throughout the Caribbean and Pacific intentionally to control invasive rats that adversely affected sugarcane plantations in the late 20th century.
Today, the mongooses run wild all over eastern Puerto Rico, gobbling up insects as their chief food source (although they’re just as happy to consume scorpions, small mammals, frogs, and birds). This frenzy is fast eradicating biodiverse regions throughout Puerto Rico and other areas where mongooses are prevalent, including certain parts of Hawaii.
One effort to monitor and work toward controlling the mongoose population has been through tracking. Researcher Diana K. Guzman-Colon studied the mongoose population in Puerto Rico through a combination of observations, molecular techniques, and tracking to develop a better understanding of mongoose’s prey species, sources of food, and population distribution. Her work has been used to educate various organizations on how to manage the invasive species best.
The Invaders of Texas Program is a citizen science program initiated by Texas Invasives that offers training and events for the management of invasive species throughout the state. The program utilizes the aid of industry members, education sectors, various organizations, and even federal agencies to battle threats to native flora and fauna throughout the state by asking teams of area volunteers—coordinated by the Lady Bird Johnson Wildflower Center—to record sightings of invasive species, each of which is logged on the Texas Invasives website to create a statewide mapping of non-native species.
To learn more about the Invaders of Texas Program, click here.
Chef Philippe Parola is a seasoned preparer of invasive species. The professional chef has brought everything from nutria to alligator to dinner plates across the country, most recently settling on normalizing the consumption of Asian carp with his business, Silverfin Fish Cakes.
Parola’s company packages and sells wholesale fish cakes comprising invasive Asian carp, representing the “first-ever, value-added products made from an invasive species for human consumption.” His website features cooking tutorials and varied encouragements for hunting the invasive fish, which compete with other species for food.
In a preemptive move to eradicate the invasive emerald ash borer throughout Prairie du Sac, Wis., the town is systematically removing the ash trees the bugs burrow in, prioritizing trees that are dead or sick. The hope is to remove trees—and, by extension, the bug—before damage spreads to other trees and canopy.
Cutting the trees down is a more eco-friendly alternative to chemical treatment, which could harm other organic matter in the trees or on the ground.
The Hawaiʻi Volcanoes National Park in 2019 marked a decade of its Youth Ranger Program on the Big Island, where 435 students to date from almost a dozen high schools have gathered to learn about the environment. One of the chief projects of this group is to clear invasive species, mainly plants, that threaten biodiversity within the park and across the Hawai’ian islands.
The biggest threats to the park include the Argentine ant, kahili ginger (pictured), miconia, coqui frog, Christmas berry, and fountain grass.
Red fire ants were first recorded in North Carolina in the late 1950s, slowly spreading throughout the state with venomous stings and housing in the form of large mounds that can easily disrupt lawns. To combat their unchecked spread, the USDA in 1958 launched a quarantine on goods from ant-infested regions to non-infested to ensure no ants get inadvertently relocated.
That ant quarantine zone in May 2019 was expanded to match a spread of inhabited area by the ants, and now includes Orange, Davidson, and Vance counties.
From Stedman Mesa to the Utah border, Colorado Parks and Wildlife is offering $20 for each northern pike caught by licensed fishermen. The price-per-head helps manage northern pike populations throughout the state, which were first illegally introduced to the state in 1950. These fish destroy other aquatic species populations with their voracious appetites.
Bonne County, Idaho, is using free ice cream to fight invasive Chinese mystery snails. The snails, which consume algae relied on by other, native species, are the product of illegal releases into Round Lake—most likely from home aquariums.
Visitors to Round Lake State Park are offered free ice cream bars or sandwiches for every dozen snails turned in.
After successfully using insects to eradicate invasive weeds for over 10 years, Helena, Mont., is now sharing its bugs to help do the same throughout the state.
The target of the bugs—in this case, the weevil—is toadflax, which comes in two invasive varieties throughout Montana. Helena’s successful biocontrol program began at the start of the 21st century and has expanded to include roughly 180 releases of half a dozen insects to eat invasive weeds, including toadflax, leafy spurge, and spotted knapweed.
The Arizona Game and Fish Department (AZGFD) during the 2018-2019 fiscal year made a 49% increase in the number of free boat decontaminations offered as a way of preventing the spread of aquatic invasive species (AIS).
Decontaminations consist of hot water washes available for free that kill off invasive species like the quagga mussel that could be stuck on a boat.
By some counts, more than half of all bird and reptile extinctions of the last 400 years have been due to rats. Besides carrying diseases like the plague, rats are blamed for destroying biodiversity in regions around the globe. Since their first Alaskan appearance in the late 18th century, a variety of methods have been employed to eradicate them.
Most recently, that method in St. Paul, Alaska, is rat snap traps, traditional bait traps secured in large yellow pails around the island to do battle against the rats and mice before they destroy native aquatic bird species and other wildlife. The program was initiated in 1995, and it persists today with rat patrollers checking traps across the island regularly and tracking numbers to ensure the rat population is kept at a minimum.
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