Look out for Invasive Species!
It sounds like something out of science fiction: Alien Plants Invade! But this isn’t science fiction.
Some people know that introducing invasive plants is bad in the abstract sense, but the reality is that these plants can out-compete native species and disrupt ecosystems. Plants aren’t the only culprits; fauna can be invasive too, especially when an introduced species lacks natural predators.
Not all non-native species are invasive however — it depends on whether or not the introduced species is utilizing the native species’ resources. Invasive species are non-native to a particular ecosystem and cause economic or environmental harm or harm to human health.
Not only is there an environmental cost, but invasive species also deal a huge socioeconomic blow. It’s estimated that invasive species cost the U.S. more than $138 billion every year in losses in forestry, agriculture and recreation/tourism from damaged habitat. Even private landowners shoulder some of the burden — the reduction in habitat quality can include increased erosion on stream banks or other blows to the local environmental makeup of the land.
One example is Japanese knotweed, which plagues many areas across the Northeast. This aggressive plant quickly regrows from its roots into acre-wide stands, and it’s an understatement to say that it’s hard to get rid of. “This invasive is so powerful, you can cut off a small piece, let it float down the river, and wherever it lands, it will take root,” said John Schmidt with the U.S. Fish and Wildlife Service in West Virginia. “It spreads vegetatively — through just a piece of it, like the root — and by seeds.”
When the Service makes the call to fight back, we typically cut down stands of the invasive species, let it regrow for a month to deplete nutrients stored in the root system, and then use an herbicide as a coup-de-grace.
Another invasive is the highly prolific nutria, often mistaken for muskrats, beavers, or otters. Nutria have destructive feeding habitats and take habitat and resources away from these native species. More than 35,000 acres of Chesapeake Bay marshes have been at risk of being destroyed by the exploding population of nutria. This kind of environmental damage would hit Maryland hard in wallet hard, too — to the tune of 35 million annually if nothing was done. Fortunately, our agency teamed up with 27 partner organizations in this attempt, the first of its kind to eradicate an aquatic mammal from mainland. This highly successful project has eradicated the exotic invasive nutria from 216,000 acres of wetlands on the Delmarva Peninsula. In fact, Blackwater National Wildlife Refuge has lost almost half of its wetlands since the introduction of nutria, which accelerate and exacerbate the effects of other forces, such as sea-level rise.
Zebra mussels are another aquatic invasive species, this one out-competing native mussels in a number of the Northeast’s waterways. (You might remember our endangered mussels with the quirky names from my video a few weeks back.) First introduced accidentally after ocean-faring vessels carried the mussel in their ballast into North American rivers, the mussel has no natural predators that effectively reduce its numbers. Zebra mussels anchor themselves by the thousands to native mussels, making it impossible for the native mussel to function. As many as 10,000 zebra mussels have attached to a single native mussel. Now widespread, this mussel takes away the little viable habitat that is left in the Northeast’s river systems after years of industry, pushing native mussels like the recently listed fluted kidneyshell and slabside pearlymussel to the brink.
So what can you do to help fight invasive species? Volunteer and help remove invasive species on public lands! But, be sure the species you’re looking at is invasive, to start with. You wouldn’t want to hurt something integral to the local habitat, or worse, something endangered — I will personally arrest you (… citizen’s arrest, that is. They don’t let interns do that, apparently).
More importantly, be careful not to introduce potentially invasive species to new environments. This includes cleaning your outdoor recreation gear after you use it, especially when you’ve been traveling that includes hiking boots! Also, don’t release any pets or fish into the wild.
By taking even small steps like these, you can cut down on the spread of invasive species in your area.