Fighting Invasive Water Chestnut Infestations
The exotic water chestnut (trapa natans) was first discovered in the Pepperell Pond impoundment on the Nashua River (on the Pepperell/Groton line) in the late 1990’s. At roughly the same time, the plants were found in the Nashua River upstream of Mine Falls Dam in Nashua, New Hampshire.
Invasive water chestnut plants create an impenetrable mat of growth that makes the river inaccessible to boating and fishing. Their growth replaces ecologically critical native plant species. When the dense mats die off in the fall, they sink and decay, which depletes oxygen levels vital to fish, destroying native fish habitat with resulting negative impact on fish populations.
As part of its work to maintain water quality, and to protect our waterways for habitat and recreation, the NRWA in early years of the infestation, helped to organize hand-pulling efforts from canoes and kayaks in Pepperell Pond. However, the exponential way in which water chestnut grows (each seed can produce up to 120 new plants) soon deemed hand-pulling ineffective in controlling its spread. By 2005, approximately 45 acres of the Pepperell impoundment were 100% covered in the plant. The NRWA and its partners worked to find funding.
In 2008, the Town of Pepperell contracted with the NRWA to manage a grant from the Massachusetts Department of Conservation and Recreation to mechanically harvest the plants. During the summers of 2008 and 2009, approximately 2,780 tons of plants were removed from the river by a private contractor. Because seeds can exist up to 12 years in sediment, harvesting needs to take place continuously for approximately 5 years before the plants can finally be controlled by hand-pulling. Funding for mechanical harvesting has not been available since 2009. NRWA continues to seek sources of funding while hosting hand-pull events with volunteers to check the spread of the plant into new regions. View a slideshow of the 2012 volunteer chestnut pull created by Denise Hurt.
Water chestnut was first documented as scattered patches above Mine Falls Dam in Nashua, New Hampshire in 1998. By 2001, approximately 14 acres of the plant covered the area just upstream of the boat ramp at the dam. In 2012 and 2013, the City of Nashua contracted with Aquatic Control Technologies, Inc. to harvest the plants. Extensive harvesting during he summer months removed much of the standing growth. Since then hand removal by volunteers has kept the water chestnut plants in check.
For more information on water chestnuts or hand-pull events or NRWA’s work to control water chestnuts, please contact Martha Morgan, NRWA Water Programs Director, at (978) 448-0299, or This email address is being protected from spambots. You need JavaScript enabled to view it..
Protecting Native Ecosystems by Combating Invasive Species
Our watershed is home to a wide variety of plants and animals. A few native wildflowers and trees you may be familiar with are the New England Aster (Aster novae-angliae), the Cardinal Flower (Lobelia cardinalis), American Columbine (Aguilegia canadensis), Flowering Dogwood (Cornus florida), White Pine (Pinus Strobus), and Red Maple (Acer rubrum). Landscaping with native species has many benefits including the fact that native species are hardy and attractive to wildlife.
Non-indigenous, or non-native, species are those that evolved elsewhere and have been purposely or accidentally relocated by humans or environmental alterations, i.e. climate change. According to the Ecological Society of America, approximately 50,000 non-indigenous species have been introduced into the United States. Not all introduced species become invasive. Some appear to be relatively benign, but others are strong competitors or voracious predators with devastating effects. The Massachusetts Invasive Plant Advisory Group defines “invasive” as “non-native species that have, or are likely to, spread into native or minimally-managed plant systems and cause economic or environmental harm by developing self-sustaining populations and becoming dominant or disruptive to those systems.”1 Invasives crowd out native species, alter natural food webs, and destroy wildlife habitat.
Although much focus is on invasive plants, our region is also dealing with invasive animals, such as the Asian Longhorned Beetle. The Asian Longhorned Beetle, native to Asia, is a destructive pest of hardwood trees, including maple, horse chestnut, birch, poplar, willow, and elm. These beetles were first discovered in Massachusetts in 2008. Since then, the city of Worcester has had to remove some 29,000 infested trees. Areas that are currently being regulated to prevent the spread of the beetles include Worcester, West Boylston, and Boylston, as well as portions of Holden, Shrewsbury, and Auburn. The public is encouraged to report sightings of the beetle or any signs of infestation. More on Asian Longhorned Beetles.
NRWA has taken action to address invasives in our watershed by:
- Identifying and controlling infestations of Purple loosestrife (Lythrum salicaria) in nine communities in our wetlands using biocontrol. About NRWA’s Purple loosestrife control project.
- Removing over 2,700 tons of Water chestnut (Trapa natans) from the Pepperell Pond impoundment of the Nashua River in Groton/Pepperell area. About NRWA’s water chestnut control project.
- Removing Japanese knotweed on the banks of the North Nashua River (Polygonum cuspidatum) in Fitchburg working with a neighborhood youth group.
- Providing free presentations on topics such as landscaping with native species, identifying and preventing the spread of the Asian Longhorned Beetle, and how boaters can prevent accidental transport of invasives from one waterway to another.
As the climate continues to change, non-native plants especially invasive ones could become even more widespread and destructive, according to a new Harvard study. The researchers found that some invasive plants have begun to flower earlier in the year as average annual temperatures have gone up. Early growth appears to give them a chance to dominate an area and destroy surrounding wildlife habitat, as well as cause other environmental problem. Invasives will continue to be a focus of NRWA efforts to protect our native ecosystems.
For more information on NRWA programs to control invasives, please contact Martha Morgan, NRWA Water Programs Director, at (978) 448-0299, or This email address is being protected from spambots. You need JavaScript enabled to view it..
1Massachusetts Invasive Plant Advisory Group. (2005). The Evaluation of Non-Native Plant Species for Invasiveness in Massachusetts. Page 5.
Invasive Plant Species Resources
Ecological Society of America
Massachusetts Invasive Plant Advisory Group
Invasive Plants of the United States: Identification, Biology and Control
Invasive Plant Index of New England
A Guide to Invasive Plants in Massachusetts by MA Division of Fisheries and Wildlife
USDA National Invasive Species Information Center- MA
USDA National Invasive Species Information Center- NH
Field Guide to Common Aquatic and Riparian Plants of NH
Landscaping with Native Species
How to Prevent Spread of Aquatic Invasive by Boats
MA DCR Boatramp Monitoring Program
NH Guide on Transport of Exotic Species on Boats
Asian Longhorned Beetle Resources
Easement Monitoring
Good land stewardship practices require that land trusts and municipalities holding Conservation Restrictions (MA) or Conservation Easements (NH)-- we’ll use CRs to refer to both here-- monitor their CR properties to ensure usage is compliant with the language of the CR and to document the overall condition of easement properties. A CR is a legal agreement between a landowner and a land trust or government agency that permanently limits uses of the land, detailing allowed uses, in order to protect its conservation values.
The NRWA’s professional staff is qualified to monitor CR properties, using “boots on the ground” inspection, GIS mapping technology, and photography to develop reports on the condition of CR properties. We also offer educational workshops on management and monitoring of CRs.
The City of Nashua contracted with the NRWA to monitor conservation easements within the City. NRWA conducted extensive field investigation and provided the City with approximately 70 monitoring reports and maps. The reports have been used by the Conservation Commission to target conservation land for remediation, clean-ups, and investigation of invasive species.
If you hold CRs and are interested in working with NRWA to monitor those properties, please contact Al Futterman, NRWA Land Programs Director, at (978) 448-0299, or This email address is being protected from spambots. You need JavaScript enabled to view it..
Protecting Wildlife Habitat
The best way to protect wildlife habitat and encourage biodiversity is through an assessment of a property’s natural resource and habitat value, using Geographic Information Systems (GIS) mapping technology and “boots on the ground” ecological inventorying, followed by development of an appropriate stewardship plan for the property.
A property may have unique, exemplary, and highly sensitive resources that require special approaches and practices to protect, preserve, and enhance its special natural features, such as rare species habitat. Rare species are identified by the MA Natural Heritage & Endangered Species Program or the NH Natural Heritage Bureau. Here stewardship objectives emphasize protecting these areas from potentially adverse disturbances and impacts. Other more typical properties are more resilient, and therefore common forestry and agricultural practices -- utilizing Best Management Practices -- and recreational activities can be practiced at sustainable levels.
NRWA can use GIS resource overlays to provide a general screen whereby lands of special resource significance and sensitivity can be mapped and identified. Landscape features such as forested areas, wetlands, streams, ponds, vernal pools, and state regulated areas like water protection zones can also be mapped as part of this overlay approach. Following such desktop mapping and data collection, we can ground-truth the information through an in-field eco-inventory, and ultimately help to create an appropriate stewardship plan.
The NRWA has undertaken several significant habitat ecological inventories in the Nashua River watershed including Focus Areas for Wildlife Habitat Protection in the Nashua River Watershed (Jeff Collins, 2000), followed in 2002 by surveys of five specific areas in the watershed (Pine Hill, Townsend Hill, Whitney Hill, Wrights Ponds). Additionally, in 2003 the NRWA received a grant to commission James DeNormandie to produce a Wildlife Habitat and Natural Resource Inventories in the Nashua River Watershed: A Citizen’s `How-to’ Guide. The document – hard-copy and electronic versions -- lays out methods (ranging from very simple to fairly complex) that can be used by citizens within the watershed to conduct habitat assessments. The Guide was distributed to all watershed public libraries and municipal conservation commissions, and may also be viewed at the NRWA’s Bill Farnsworth Conservation Clearinghouse.
The NRWA also collaborates with local sportsmen’s groups, such as Trout Unlimited, Ducks Unlimited, and local Rod and Gun Clubs, to restore natural habitat by protecting water quality; by creating naturalized stream flows for fish; and by preventing invasives from destroying habitat, such as our water chestnut control project. We work with partners on land protection projects to preserve open fields for bird habitat and unbroken forests to provide wildlife corridors. We offer free public presentations on topics such as native wildlife from large mammals (bears, moose) to cold and warm water fish. Presentations also cover how to create wildlife habitat on your property, why forests are essential to the survival of neo-tropical migrant birds, or the importance of a Forest Management and Stewardship Plans for landowners.
For more information about protecting wildlife habitat, land stewardship, and best management practices, please contact Al Futterman, NRWA Land Programs Director, at (978) 448-0299, or This email address is being protected from spambots. You need JavaScript enabled to view it..
Stewarding Special Landscapes: Areas of Critical Environmental Concern
The Nashua River watershed is home to three of the Commonwealth’s twenty-eight Areas of Critical Environmental Concern (ACEC), comprising more than one quarter of all ACEC land in Massachusetts. The Central Nashua River Valley ACEC was designated in 1996 and includes 12,900 acres in the communities of Bolton, Harvard, Lancaster, and Leominster. Details and maps of the Central Nashua River Valley ACEC. The Squannassit and Petapawag ACECs, designated in 2002, are the two largest ACECs to date, with Squannassit covering 37,450 acres and Petapawag covering 25,630 acres in the communities of Ashby, Ayer, Dunstable, Groton, Harvard, Lancaster, Lunenburg, Pepperell, Shirley, Townsend, and Tyngsboro. Details and maps of the Squannassit ACEC; Details and maps of the Petapawag ACEC.
An Area of Critical Environmental Concern (ACEC) is a special designation given by the Commonwealth of Massachusetts to a region that has high quality, unique, and significant natural and cultural resources. Nominations for ACEC designation are made at the community level and proceed through a process of compiling nomination papers detailing the area and its valuable assets, public outreach and education, review by the state's Executive Office of Energy and Environmental Affairs (EOEEA), public hearings, and finally, if appropriate, designation by the Secretary. More about the Commonwealth's ACEC program.
The NRWA was a key partner in the nomination process for the Squannassit and Petapawag ACECs. The many unique qualities of the region led to their designation. The Squannassit/ Petapawag region contains one of the most remarkable concentrations and varieties of glacial landforms in New England. These landforms contributed to the highly variable nature of soils and complex hydrologic systems within the region. Combined with regional geography, these characteristics resulted in a diversity of habitat types and rich biodiversity. Remarkable concentrations and varieties of wildlife, including rare and endangered and/or threatened plant, animal and fish species, reside in the Squannassit/Petapawag region. Both ACECs contain eighteenth and nineteenth century structures and landscapes which provide significant historical resources. In addition, both Squannassit and Petapawag ACECs contain extensive conservation lands and recreation areas.
The NRWA facilitates a Stewardship Committee of local citizens that focuses on expanding public outreach and education on significant stewardship topics as they emerge. The Committee played an important role in launching an NRWA project to raise galerucella beetles for release to control invasive purple loosestrife.
For more information about the Areas of Critical Environmental Concern, please contact Al Futterman, NRWA Land Programs Director, at (978) 448-0299, or This email address is being protected from spambots. You need JavaScript enabled to view it..
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