Invasive species are taking over. It sounds like a headline from a supermarket tabloid — but it's true. They're ruining the places and threatening the creatures that we treasure. A recent study by a United Nations team of researchers from 49 countries finds that some 3,500 invasive species are causing a whopping $423 billion worth of damage every year, and they're responsible for 60% of plant and animal extinctions.
Here in Maine, the problem is not new, but it's accelerating in part because of climate change. Of the 2,100 plant species recorded in Maine, the Department of Agriculture, Conservation and Forestry says about a third are not native, and a small fraction are considered invasive, with the potential to cause extensive harm to the landscape.
Invasive species aren't just plants. They're animals, insects, mollusks, crustaceans and fish. They grow and produce rapidly, with or without help from humans (also an invasive species), and their introduction causes major disruption, outcompeting native species with environmental and economic costs. Those "costs" can include diminished property values, degraded water quality and loss of recreation opportunities as well as effects on human health
What can you do? Scientists say the best way to fight invasive species is to prevent them from occurring in the first place, and that starts with awareness.
Over the next two weeks we'll be highlighting some of the plants, animals and pests that are considered invasive here in Maine. Other resources are here:
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"It's these extractive relationships that we see in certain kinds of cultures," says UMaine Professor Jacquelyn Gill. "But those relationships are not universal. They're not practiced by all people everywhere." -
Three different invasive plants have been discovered on Cobbossee Lake since 2018, including Eurasian water milfoil and its better-known relative, variable leaf milfoil. Climate change is helping such invasives spread on Maine lakes and streams. -
It's found all around New England, an aggressive climbing vine that grows wildly out of control along roadsides, can topple trees and take over entire woodlots. Asiatic bittersweet (not to be confused with the American variety) snuffs out native trees, shrubs and plants. If there's a vacant building in your neighborhood, chances are the vine has made its mark. -
The name Himalayan balsam sounds at once exotic and fragrant. But it's actually an aggressive invasive plant that has established itself in Midcoast Maine. Unlike some other invasive species in the state, in can be managed with just a little elbow grease — and some healthy persistence. -
The emerald ash borer arrived in Maine in 2018. Now strategies are underway to protect ash trees from the invasive beetle. -
Conservationists are using a variety of approaches to limit the invasive types of shrubby honeysuckle that are growing in the town of Harpswell and elsewhere. -
Conservationists in the Rangeley Lakes region are calling on the public to help remove an aggressive non-native aquatic species, the rusty crayfish, that can disrupt the natural habitat of its native counterparts. -
Sometimes confused with bamboo, knotweed has a hollow stem and flat, shovel-shaped leaves as big as your palm. It's been in the U.S. for centuries — initially brought here as an ornamental species. But it's now considered one of the most invasive plants in the world and one of the most damaging in Maine. -
Once the northern pike is introduced, there is little management that can be done as the fish has no major predators. But while the presence of northern pike brings about immense ecological implications, some fishermen are embracing them. -
The discovery of an invasive vine in Maine has alarmed state officials who keep an eye out for non-native species. It's called the mile-a-minute vine, and despite the name, it doesn't grow 60 miles in one hour. But it can grow up to six inches in a day.
