Green Living

Long Island Invaders

August 07, 2009 - by Molly Mann

They don't come in spaceships, but these little green guys will wreak havoc on our island if we let them. Invasive plants are a huge problem around the globe, as international travel becomes more common and plant spores often hitch a ride with travelers and traded goods. Close to home, some of these plants threaten to crowd out native species and upset the delicate balance of our ecosystem.

Where I live now, in Oyster Bay, water chestnut is a huge problem. On July 8, 2009, volunteers pulled up more than 4500 pounds of water chestnut from Mill Pond at the Oyster Bay National Wildlife Refuge. Water chestnut, which is unrelated to the edible Chinese water chestnuts, is native to Europe and Asia. It sets roots at the bottom of a body of water, and forms dense, floating mats on
the water’s surface. These mats restrict light availability to aquatic animals and plants, reduce the oxygen content of the water, and displace native vegetation. Water chestnut can also limit boating, fishing, and swimming, and can injure anyone who steps on the sharp, spiny adult seeds.

Like other invasive species, water chestnut's growth is fast and furious. It was first documented in the United States in Massachusetts in the late 1800s, and has been shown to increase tenfold within one year in some areas. Mill Pond residents first observed water chestnut growth in 2005 and the Wildlife Refuge declared an infestation in June 2008. Fortunately, volunteers are working had to remove the species, but they're working against a plant that can reproduce itself 300 times per year.

Invasive species come to an area accidentally, for the most part. Because such a wide range of plants are available in just about every nursery, people plant these foreign seeds in their yards and the runoff carries them to public lands. Seeds and spores can also hitch rides on the soles of shoes and be transported to different areas. It's much easier to prevent spreading these plants and animals than to try to control them after the fact, since most are incredibly hardy and prolific. Here's what you can do to be part of the solution:

• Familiarize yourself with native species of plants and use only these to grow your garden.
• Never release any animals you buy in a pet store, especially exotic animals.
• Use a reputable, local nursery and talk about where your purchases came from, as they can host hitchhiking invasive bugs.
• Inform others about the dangers of invasive species, and be on the lookout for unfamiliar plants around your community.
• And, of course, volunteer to help remove them!

Non-native species are mostly silent invaders; we don't tend to notice them until they've completely taken over and upset the delicate natural balance of our area. But there is a way to fight back, and we simply can't abstain from doing so.