Statement of Ecological Significance: The Watershed

Geography The Nashua River watershed drains 538 square miles in North Central and southern . The Nashua River has two main branches: the , which is formed by the junction of the and Flag Brook in West Fitchburg, and the , which flows from The Dam to join the North Nashua River in Lancaster. The mainstem of the river then flows north to join the in Nashua, NH. The terrain of the Nashua River watershed is formed by rolling hill, which are more rugged to the north and west. The Nashua River valley follows a broad flood plain, bordered by hills, along the river's mainstem from Lancaster to Nashua. The watershed is located in the central highlands 'of southern New England. The watershed's topography shows the effect of the movement and melting of glaciers; many eskers and kettleholes can be found in the watershed. During the last ice age, rocky soil was deposited in uplands while the lowlands were buried in sand and gravel carried by glacial meltwater. Many of the watershed's rivers were once chains of glacial meltwater dammed by accumulations of rock and soil. The watershed therefore has a broad range of soil types, which support a diversity of plant community types.

Landscape The Nashua River watershed includes areas of concentrated development as well as large areas of undeveloped open space. The Oxbow National Wildlife Refuge and the South Post area of Devens, located in the central region of the watershed, together make one of the largest contiguous blocks of undeveloped land in southern New England. This undeveloped area provides important habitat for several species of state listed wildlife including Blandings and Spotted turtles. This region, as part of the Atlantic Flyway, serves as a resting and foraging stop for migrating waterfowl such as black ducks, hooded mergansers, and wood ducks. Since 1970, over 212 species of birds have been recorded in this region, including the state-listed Cooper's hawk, the American bittern, and the grasshopper sparrow. During the past 100 years the landscape and ecology of the watershed changed dramatically as land use in the watershed shifted from agriculturally based activities to residential and industrial use. These changes brought more people and development to the watershed. Currently, polluted runoff and increased water withdrawals threaten habitat, water quality, and water quantity in the Nashua River watershed. These threats in turn place invertebrates, fish, and wildlife populations at risk. The NRWA has instituted several projects which evaluate polluted runoff and habitat loss. The NRWA's Volunteer Water Quality Monitoring program tracks polluted runoff and nonpoint source pollution by engaging local citizens to conduct chemical water quality monitoring on local rivers and streams. Citizen monitors use the program's data to address issues concerning water quality and habitat. NRWA's volunteer monitors and Stream Team Members also participate in a habitat assessment program by conducting habitat and land use surveys on "remote" streams and rivers in the watershed. These activities directly benefit fish and wildlife as the data from the surveys are used to prioritize land suitable for protection and to seek areas in need of more in- depth monitoring.

Wildlife Many protected riparian corridors exist in the watershed. Mammals, birds, reptiles and amphibians are dependent on the habitat and migration routes provided by the Nashua River watershed's undeveloped and vegetated riparian corridors. Since wildlife often utilizes areas adjacent to riparian corridors, it is important to protect upland and lowland habitats associated with riparian areas. In the Nashua River watershed wildlife including otter, black ducks, white tailed deer, muskrats, and other species depend on a connection to riparian habitats. For example, black ducks nest in upland habitats, but will travel to neighboring wetlands to raise their young. However, as development escalates in the Nashua River watershed, wildlife habitats become fragmented which decreases the ability of wildlife to travel to and from important riparian areas. NRWA's land protection and land owner education efforts, along with the Volunteer Water Quality Monitoring and Stream Team Programs, help benefit wildlife and wildlife habitats through scientific research and advocacy. A main programmatic goal of the NRWA is to develop programs that enable citizens to understand the important connection between careful land use, habitat protection, and water quality. One example of an ongoing NRWA program that addresses habitat issues is the NRWA Bluebird Monitoring Program. The Bluebird Monitoring Program, which is funded by a grant from the Bluebird Recovery Program, instructs citizens in the habitat needs of Bluebirds and the construction, placement, and monitoring of bluebird boxes. The Bluebird Monitoring Program also addresses Bluebird habitat protection. Monitors in the program are working to establish a watershed-wide "bluebird trail" of connected nesting boxes.

Fisheries & Aquatic Invertebrates Protection of the Nashua watershed's riparian corridors and the land adjacent to them is also important for maintaining healthy fish populations. Presently, sedimentation, nonpoint source pollution, and habitat loss threaten fisheries in the Nashua River and its tributaries. Both coldwater and warmwater fish are present in the watershed's waterways including brook trout, brown trout, and several species each of bass, sunfish, perch, and dace. Coldwater fish species are abundant in tributaries such as the Squannacook and the Nissitissit Rivers. Both rivers are renowned for their recreational fisheries. In 1996 the NRWA and NRWA Stream Team members from the Squannacook Task Force conducted a stream bank restoration project on the . The purpose of the project was to decrease sedimentation in a portion of the river that was being caused by an eroding section of stream bank. The restoration project, which engaged anglers, concerned residents, and NRWA staff, directly benefited fish and invertebrates in the Squannacook River. The Squannacook, Stillwater, and Nissitissit Rivers contain species of state-listed freshwater mussels including Alismidonla varicosa, Strophitus undulatus, and Alasmidonta undulata. Protection of vulnerable fauna such as fresh water mussels, which require a high level of water quality, depends on protecting riparian corridors and adjacent lands. The NRWA has conducted freshwater mussel surveys for the Massachusetts Natural Heritage Endangered Species Program in 1997 and again in l998. This research helps identify mussel populations, evaluate mussel habitat, and prioritize protection efforts for significant mussel beds. Many tributaries in the Nashua River system support taxa of aquatic insects deemed "sensitive" to pollution including those in the orders: Ephemeroptera, Plecoptera, and Trichoptera. Studies of aquatic insects in the watershed indicate a trend toward an overall improvement in water quality. However, threats to these populations increase as development pressure in the watershed affects habitat and water quality. To illustrate the relationship between land use and water quality, NRWA volunteer water quality monitors conduct aquatic insect studies on several tributaries in the watershed. Data from these studies are useful for determining water and habitat quality thereby helping the NRWA prioritize lands for protection.

Closing At the watershed's headwaters, several pristine waterways are bordered by undeveloped, biologically diverse, forested land. This diverse forest community occurs because the Nashua River watershed lies in a transition zone between the east-central forest type, dominated by oaks and hickories, and the northern hardwood forest type, dominated by beech, birch and maple. Conifers are prevalent in certain areas: pines in sandy soil or in former fields; hemlocks on cool, north facing slopes. Recently, a stand of old growth forest was identified in a westerly region of the watershed on Mount Wachusett. In the watershed's riparian areas, the diversity of vegetation types provides ample cover and food for invertebrates, fish, and wildlife. Riparian forests and wetland areas in the watershed serve as natural buffer zones which protect water quality and provide important habitat. However, as unplanned development increases in the Nashua River watershed, both water quality and wildlife habitat are threatened. The NRWA's mission statement includes developing programs that help provide "a healthy ecosystem with clean water and open spaces for human and wildlife communities." Through programs and projects that incorporate a combination of scientific research, advocacy, and community outreach, the NRWA works directly with local citizens and policy makers. By taking a hands-on, action oriented, citizen-based approach to land and water quality protection, the NRWA helps watershed residents understand the vital link between water quality, land use, and protecting valuable habitat for the benefit of the Nashua River watershed's fish and wildlife.