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Region 1: EPA New England

Fighting the Spread of Invasive Species in Connecticut

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

CT | MA | VT

By Robert W. Varney
August 9, 2004

Newspaper headlines across New England tell the story: "Invasive plants threaten region's environment" "Foreign species could threaten scallop fishing" "New weapon against invasive plants."

No. This is not from your supermarket tabloids. Every week newspapers in Connecticut, New England and across the country are reporting on invasive animals and plants being introduced to areas where they did not exist before, and how they threaten native ecology.

Like all New England states, Connecticut is suffering from an invasion of these plant and animal species into its landscape, fresh waters and marine waters. There are at least 96 species of invasive or potentially invasive plants in Connecticut, including 22 species of aquatic plants. Examples include variable leaf water milfoil, water chestnut, purple loosestrife and fanwort.

Once invasive species are introduced, managing and controlling them is a significant challenge. That's why the Connecticut Legislature recently passed a new law prohibiting the sale and importation of invasive plants. The law, which took effect in June, mandates that plant species listed as invasive in the state may not be sold, cultivated, distributed or transported either by commercial growers or individuals. This is a terrific step forward in the fight against invasive plants.

Invasive species are a concern for a number of reasons. They generally lack predators or other natural controls and can tolerate a wide variety of environmental conditions, which allows them to easily establish self-sustaining populations. Once established, invasive species threaten the natural diversity and abundance of native species, as well as the stability of entire ecosystems. Native species lose in the competition for habitat, breeding sites and food. As a result, food webs are destroyed. And, lastly, the economic consequences can be severe.

Zebra mussels, a highly invasive and disruptive freshwater species, have become established in East and West Twin Lakes in Connecticut, and have the potential to invade the Housatonic River. These small mussels can form extremely dense colonies, blanketing areas where native mussels live and smothering them. They can also disrupt the ecosystem from the bottom up by removing food for fish and other native species. Furthermore, they can cause thousands of dollars of damage to a town or company's water intake pipes by growing on them and clogging them. Once established in a lake, control is impossible. Milfoil and other invasive aquatic plants can grow so dense that they clog lakes and ponds and reduce recreational opportunities as well as fish habitat. Control of these plants is sometimes possible, but is usually exceedingly difficult and expensive.

Invasive species can be transported among water bodies by boats and trailers and, even, scuba divers and fishermen. Bait buckets dumped carelessly can introduce foreign and invasive fish, plants and plankton into a pond or river. Waders and boots can move mud with invasive animals (such as the New Zealand mud snail) or parasites like whirling disease (now present in Vermont's Battenkill River). Scuba divers can unwittingly transport zebra mussel larvae in any water pooled within their equipment. Recreational boats and trailers can tow nuisance aquatic plants like variable leaf milfoil and introduce them into new ponds and lakes. Aquarium plants and pets released into ponds and rivers can establish thriving colonies of organisms that disrupt the native ecosystem. Ballast water from ships often introduces new marine species, such as the Asian shore crab, the leafy red algae and the invasive sea squirt.

This country spends hundreds of millions of dollars every year trying to control aquatic invasive species. Money is most wisely spent on prevention since, once an invasive species takes hold, it is virtually impossible to eliminate it. Consider these figures:

  • Controlling invasive species costs $200 to $2,000 per lake-acre each year.
  • Research in Vermont shows that invasive plants can cost shoreline owners more than $12,000 each in lost property values on infested lakes.
  • Economic losses in the U.S. from invasive species are estimated at $78.5 billion annually.

We all need to realize that preventing the spread of invasive species will require hard work. State, local and federal governments must play a leading role in identifying and preventing the spread of invasive species. However, this problem is too large for governments to tackle alone. To face this challenge, we need to quickly and dramatically increase the number of watershed groups, lake associations, boaters, fishermen, divers and citizen volunteers who can act as our ‘eyes' and ‘ears' to catch and prevent these threats as early as possible. Let's all work together!

Robert W. Varney is regional administrator of the U.S. Environmental Protection Agency's New England Office. For more information about invasive species in Connecticut, visit the state's web site at http://www.dep.state.ct.us/cgnhs/invasive.htm . Click icon for EPA disclaimer.

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