Region 1: EPA New England
Fighting The Spread of Invasive Species in Maine
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
ME | NH |
By Robert W. Varney
August 20, 2003
Newspaper headlines across New England tell the story: “Lake residents worry about wild growth of weeds” ; “Foreign earthworms threaten forest health”; “Maine’s milfoil madness.”
No. This is not from your supermarket tabloids. Every week newspapers in Maine, 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, Maine is suffering from an invasion of these plant and animal species into its landscape and coastal waters. At least 45 species of invasive plants and animals now exist in Maine. Plants such as purple loosestrife, common reed and glossy buckthorn dominate many of Maine’s freshwater marshes and forested wetlands, especially in southern and central Maine.
Once invasive species are introduced, managing and controlling them is a significant challenge. That’s why the Maine Department of Environmental Protection (DEP) is spearheading an effort to prevent the introduction and spread of invasive species.
Last fall, DEP issued an Action Plan for Managing Invasive Aquatic Species. This pro-active, four-year plan focuses on educating the public, preventing new invasive aquatic species and limiting the spread of established populations. As part of this plan, watercraft are inspected for milfoil and other invasive aquatic plants. There will also be monitoring and rapid response to new infestations and laws regulating fish stocking will be more tightly enforced.
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.
Among the most common invasive species in Maine is the variable-leaf milfoil, an aggressive aquatic plant that has infested at least 15 ponds and streams throughout western, southern and central Maine. Hydrilla, an even more aggressive aquatic plant, was found last fall in Pickerel Pond in Limerick. Northern pike, illegally introduced into the Belgrade Lakes chain in the 1970s, exists in at least 16 lakes in the Kennebec, Androscoggin and coastal river watersheds. Pike feed on other fish, and their presence on one lake is suspected of destroying one of the state's premier landlocked salmon populations.
In addition, smallmouth and largemouth bass are widely established in southern, central and parts of eastern Maine, also through mostly illegal introductions. One of these illegal stockings was at Umbagog Lake in the upper Androscoggin River drainage, where they now threaten one of the nation's premier wild brook trout populations. The green crab, a marine species introduced to coastal waters in the mid-1800s, suppresses economically valuable clam populations.
Invasive species can be transported among water bodies by boats and trailers. Untreated biological waste from agricultural, seafood and other food processing facilities can also carry foreign organisms. In addition, ballast water from ships often introduces new marine species.
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.
According to the Maine DEP, if the state experienced a fraction of Vermont’s infestation rate just in its five southern counties, the property value loss alone could exceed $11 million and control costs could reach $2 to $4 million a year. These figures would be substantially higher when lost tourism dollars, fishing and water sports opportunities are factored in.
With summer coming to a close, we all need to realize that preventing 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. But government personnel cannot be at every boat ramp and constantly patrol every lake and waterway. To face this challenge, we need to quickly and dramatically increase the number of watershed groups, lake associations, boaters, fishermen 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. More information about
the state’s action plan is available at the Maine DEP web
site at www.maine.gov/dep/blwq/topic/invasives
