Invasive Species Overrun U.S. Wildlife Refuges

By Cat Lazaroff

WASHINGTON, DC, October 15, 2002 (ENS) - Invasive species are wreaking havoc on wildlife refuges across the country, warns a new report released in conjunction with National Wildlife Refuge week. Members of Congress joined the report's sponsors at the National Wildlife Refuge Association in calling for new efforts to stem the flow of nonnative species into U.S. ecosystems.

Invasive species - foreign insects, plants and animals that wreak havoc on native ecosystems - cause more than $100 billion damage each year. Invasive plants alone have invaded more than 100 million acres of land nationwide, and almost eight million of those acres are in wildlife refuges, areas created to protect the most important examples of biological diversity across the country.

Purple loosestrife, is crowding out native plants from about 400,000 acres of federal wetlands, marshes and meadows. (Photo courtesy King County Department of Natural Resources and Parks)

The NWRA report, "Silent Invasion," profiles 12 of the most damaging invasive species, including purple loosestrife, a nonnative plant which now infests about 400,000 acres of federally owned wetlands, marshes and meadows in every state except Florida. Florida has its own problems with another invasive plant: melaleuca, a fast growing tree that has begun to crowd out native plants in the Florida Everglades.

The report also documents how 12 diverse refuges in as many states are working to address this ecological crisis. For example, at Ellicott Slough National Wildlife Refuge (NWR) near Monterey Bay, California, refuge personnel and state officials are working to remove eucalyptus, pampas grass and other invasive species that are taking over the native habitat of one of the last remaining populations of Santa Cruz long-toed salamanders.

Nutria, aquatic mammals introduced into North America for fur farming, now live wild in fresh and salt water ponds and swamps throughout the mid-Atlantic, southeast, Great Lakes, and northwest states, where they disrupt irrigation and destroy native aquatic ecosystems. (Photo courtesy U.S. Geological Survey)

At the Alaska Maritime NWR, native species are falling prey to invading populations of fox, ground squirrel, reindeer, cattle and other nonnative mammals. While refuge staff and other federal personnel are slowly attempting to remove the invaders, they are also working to prevent new invasions by monitoring ship traffic and preventing rats from shipwrecks from reaching pristine island habitats.

"We consider a rat spill worse than an oil spill," refuge biologist Vernon Byrd states in the report.

Leafy spurge uses toxins to halt the growth of other nearby plants, displacing native vegetation. It is found across the U.S., except in southeastern states. (Photo courtesy King County Department of Natural Resources)

"'Silent Invasion' makes it crystal clear that we have to act now before it is too late. To stop the Refuge invaders, we need a three part strategy - educating and mobilizing volunteers, deploying rapid response strike teams across the nation and implementing the strategic management plan of the National Invasive Species Council, a Presidentially mandated commission," said Hirsche. "The approach outlined in 'Silent Invasion' is already receiving bipartisan support and we urge the U.S. Congress and Bush Administration to fund our national campaign to protect our national wildlife refuges from certain destruction."

Among the report's recommendations is the training and deployment of 5,000 volunteers - about 10 per refuge - that could help spot invaders before they gain a foothold. The report also calls for the formation of 50 rapid response teams that could quickly fight early infestations before they begin to dominate native landscapes.

Spotted knapweed, now found in most states including Hawaii, suppresses the growth of native plants with chemicals released from its roots. (Photo courtesy Washington State Noxious Weed Control Board)

"Utilizing volunteers and mobile strike teams is a practical and affordable use of taxpayer funds to solve a problem that could effect 37 million refuge visitors annually," added Hirsche. "Recognizing the problem early on and responding rapidly are a crucial elements to this campaign. We need to catch the invasives and work to eradicate them before they swell to uncontrollable proportions."

Representative Wayne Gilchrest, a Maryland Republican, spoke in support of the NWRA's recommendations. Gilchrest has introduced legislation to reauthorize, strengthen and expand the National Invasive Species Act, and establish a screening process for detecting new invaders.

Representative Wayne Gilchrest (left) and NWRA president Evan Hirsche. (Photo courtesy NWRA)

Senator Jim Jeffords, the Vermont Independent who chairs the Senate Environment and Public Works committee, noted that refuges in the northeast face a number of invaders, including an aquatic weed known as the water chestnut.

"Prevention is the key word in this battle to protect our national refuges," Jeffords said. "Educating and mobilizing of a nationwide network of volunteers is a cost effective and practical solution."

A USFWS employee pulls a handful of water chestnut, a nonnative weed, from wetlands in Lake Champlain. (Photo courtesy USFWS)

The "Silent Invasion" report was released in conjunction with National Wildlife Refuge Week, October 13 - 19. The annual event will be celebrated in a variety of ways at the U.S. Fish and Wildlife Service's (USFWS) 95 million acres of refuges, wetlands and special management areas across the nation.

This year's refuge week also kicks off the celebrations of the national wildlife refuge system's centennial anniversary. The first national wildlife refuge was established in Pelican Island, Florida on March 14, 1903, and there are now 540 wildlife refuges located in all 50 states.

Giant salvinia is a fast growing fern that can clog ponds and lakes. This invader is now found in the southeast and in California and Hawaii. (Photo courtesy Agricultural Research Service)

More than 400 national wildlife refuges are open to the public, offering a variety of outdoor activities including fishing, hunting, environmental education, wildlife observation and photography. Many refuges offer additional opportunities for nature hikes, bird tours, wildlife drives and other activities.

Many events this year will focus on the threat posed by invasive species. On Wednesday, for example, Lynn Scarlett, assistant secretary of Interior, will be at Ding Darling NWR on Sanibel Island, Florida, for an event highlighting invasive species. On Friday, the Heinz Invasives Species Event will be held at the Tinicum NWR in Philadelphia, Pennsylvania with guests from the Interior Department and the USFWS.

Wild pigs are the descendants of boars and domestic pigs. In Hawaii, these large pigs damage wet forests and spread disease to animals and humans. (Photo courtesy USGS Pacific Island Ecosystems Research Center)

For more information on National Wildlife Refuge Week, including a list of events near you, visit: http://refuges.fws.gov/

To read the NWRA report "Silent Invasion," visit: http://www.refugenet.org/