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Native freshwater mussels grew more slowly when invasive Asian clams (Corbicula fluminea) were abundant. The study was led by Wendell Haag, a USDA Forest Service research fisheries biologist. The study, "Abundance of an invasive bivalve, Corbicula fluminea, is negatively related to growth of freshwater mussels in the wild" was published in the journal Freshwater Biology. Mussels live out of sight – buried in the river bottom, eating algae and other small particles of organic material. Mussels are filter feeders and key members of aquatic ecosystems. Unfortunately, mussels are disappearing worldwide, and about 70 percent of the 300 mussel species native to the U.S. are in danger of extinction. Addressing mussel declines is difficult because their causes are mostly unknown.

The Arkansas Department of Agriculture is notifying the public that a new invasive grass species, Cogongrass, has been confirmed in Arkansas for the first time. For several years botanists and land managers have been on the lookout for Cogongrass (Imperata cylindrica) in southern Arkansas. This aggressive species, native to Southeast Asia, has spread rapidly across the Deep South over the past few decades. Cogongrass is considered one of the worst invasive species in the world, causing both economic and ecological damages that impact forestry, agriculture, rangeland, and natural ecosystems.

Any sightings of Cogongrass in Arkansas should be reported to Paul Shell, the Department's Plant Inspection and Quarantine Program Manager, at paul.shell@agriculture.arkansas.gov or 501-225-1598.

Imagine walking through a forest, with leaves crunching beneath your feet. Underneath those crunchy leaves is a complex ecological realm. “Soil is teeming with life,” says U.S. Forest Service research ecologist Mac Callaham. “Most people don’t think about it because they don’t see the soil fauna.” Soil fauna includes centipedes, millipedes, springtails, nematodes, insect larvae, and earthworms. “Springtails are very small arthropods,” says SRS ecologist Melanie Taylor. “Earthworms are the giants of soil fauna.” Taylor, Callaham, and lead author Meixiang Gao recently published a study on non-native earthworms and the food web. The study was published in the journal Soil Biology and Biochemistry.

European green crabs are one of the most widespread invasive marine species on the planet, originally reaching Washington in 1996. When green crab populations grow too large, they compete with other shellfish, disturb the sediment, and destroy the eelgrass that is an important habitat for Dungeness crab and salmon. The U.S. Geological Survey (USGS) is working to increase the effectiveness of Washington’s green crab early detection and rapid response program. Research conducted at the USGS' Western Fisheries Research Center aims to improve native shellfish habitat and limit the spread of European green crabs in coastal waters.

The green crab, Carcinus maenas, is a widely distributed invasive species that eventually alters its new environment. It's assumed that such species have high genetic diversity, or a variety of characteristics allowing them to adapt and thrive. But the green crab has low genetic diversity, while still spreading rapidly in a new part of the world. A U.S. National Science Foundation-funded study led by Carolyn Tepolot of the Woods Hole Oceanographic Institution is investigating the adaptive mechanisms of the green crab along the west coast of North America, where it has shown extensive dispersal in the last decade despite minimal genetic diversity. The results are published in Molecular Ecology. The project is a collaboration among scientists at WHOI, Portland State University, the Smithsonian Environmental Research Center and the University of California, Davis.

See also: Spotted Lanternfly in Home Gardens for more resources

See also: Invasion Watch Profiles for more resources

See also: Invasion Watch Profiles for more resources

The invasive Asian jumping worm (Amynthas agrestis) has many common names: Alabama jumpers, Jersey wrigglers, wood eel, crazy worms, snake worms, and crazy snake worms. “Invasive Asian jumping worms got their name because of the way they thrash around,” said Mac Callaham, a Forest Service researcher who specializes in soils. “They can flip themselves a foot off the ground.”

Like other earthworms, Asian jumping worms eat tiny pieces of fallen leaves. But there’s a problem. Those fallen leaves make up the top layer of forest soil. The litter layer, as it’s called, is home to a vast number of tiny animals. Many plants can’t grow or spread without the layer of leaf litter. “Soil is the foundation of life – and Asian jumping worms change it,” says Callaham. “In fact, earthworms can have such huge impacts that they’re able to actually reengineer the ecosystems around them.”

What could be more 2020 than an ongoing invasion of jumping worms? These earthworms are wriggling their way across the United States, voraciously devouring protective forest leaf litter and leaving behind bare, denuded soil. They displace other earthworms, centipedes, salamanders and ground-nesting birds, and disrupt forest food chains. They can invade more than five hectares in a single year, changing soil chemistry and microbial communities as they go, new research shows. And they don’t even need mates to reproduce...

The Invasive Mussel Collaborative announced today that it has released a new strategy to reduce invasive mussels and their negative impacts. The Strategy to Advance Management of Invasive Zebra and Quagga Mussels is intended to drive investments, policy, and research around invasive mussels across the Great Lakes region and beyond. Since their initial discovery in 1989, zebra and quagga mussels have had dramatic impacts on the Great Lakes ecosystem and economy, including changes to the food web, degrading fish habitat, interfering with drinking water systems and damaging tourism and recreation economies. Today, these mussels continue to spread to new water bodies across the U.S. and Canada.