Southwestern Maine Hunting Report: December 27, 2006
Scarborough Marsh WMA Restoration
Located just 9 miles south of Portland and amidst the rapidly growing town of Scarborough is the largest, most ecologically diverse saltmarsh in the state. The estuary is the meeting place of five rivers and the Atlantic Ocean. This exceptional wetland, totaling over 3,100 acres is owned by the Department and managed as the Scarborough Marsh Wildlife Management Area (WMA). MDIFW surveys indicate the marsh provides habitat for the highest number of water dependent birds in the state, including resident and migratory waterfowl and wading birds. Though this WMA was largely acquired and managed for waterfowl such as the black duck, blue-winged teal and wood duck, the marsh provides habitat for many other wetland species, including at least seven state and federally listed birds. Today, as in the past, the marsh provides many recreational opportunities such as waterfowl hunting, trapping, striped bass fishing, shellfish harvesting, canoeing and bird watching. The Nature Center, managed by Maine Audubon Society in partnership with MDIFW, welcomes over 10,000 visitors annually for educational programs.
Much like the state’s vast inland forests, salt marshes, including Scarborough, have a long history of human use. Prior to European settlement, the Sokokis Indians maintained a settlement on Winnock’s Neck, where they harvested shellfish, fish, seal and waterfowl. European settlement beginning in the 1600′s brought livestock to the area. The marsh then became a source of hay, with the cordgrasses (Spartina spp.) and blackgrasses (Juncus spp.) considered most valuable. The shorter the hydroperiod on the marsh, the higher the yield of hay, so marshes throughout the east coast were parallel ditched to drain the tidal water. In addition, large earthen dikes were built and sluice gates were installed to reduce the influence of the tides on the marsh. This type of farming was physically demanding and technically challenging, yet the marshes were extensive, productive, required no cultivation and could be quite profitable. The harvesting declined in the early 20th century due to competition with larger farms inland. Later, in the early 1920′s, the marshes endured another phase of ditching for the purposes of controlling mosquitoes. Additional alteration of the marsh has resulted from the establishment of three major transportation corridors, two railroad lines and U.S. Route 1. These practices were done at a time when the ecological value of a salt marsh was not fully realized. These values were compromised through changes in hydrology, soils and vegetation types, including the spread of invasive plants. The state acquired Scarborough Marsh largely between the years 1957 and 1978, and smaller acquisitions continue today through funding from Pittman-Robinson funds, state bond monies and private donations. Former MDIFW Biologist Russell Degarmo was instrumental in the acquisition of the marsh in the early days. Much of the initiative for restoring the marsh can be attributed to the work of MDIFW’s Region A Wildlife Biologist, Phil Bozenhard. A group of citizens and conservation groups concerned about the future of the marsh established the Friends of Scarborough Marsh. They have been an important liaison to the community and are fully invested in the planning and restoration of the marsh.
Large-scale restoration of the marsh requires extensive resources, community support and technical expertise from natural resource professionals in a developing new science. MDIFW has collaborated with many dedicated partners in this effort including the USDA Natural Resource Conservation Service, USFWS Gulf of Maine Program, Friends of Scarborough Marsh, Ducks Unlimited and Maine Audubon. Restoration projects begin with baseline data from a preconstruction monitoring plan. Based upon this data, a restoration plan tailored to the specific site is developed. Another important component of this work is a period of post-construction monitoring, during which the effectiveness of the plan can be evaluated. The salt marsh is restored largely through the plugging of ditches, removal of berms, lowering of marsh elevation, creation of saltwater pannes, modification of tidal restrictions and removal of stands of phragmites; a prolific invasive aquatic plant that compromises waterfowl habitat and vegetative diversity. Completed project sites include Seavey Landing, Mill Brook and Cascade Brook. The Seavey Landing project restored 38 acres of marsh through plugging and excavation of pools so attractive to waterfowl and wading birds. The restoration of Cascade Brook was required after a culvert on Old Blue Point Rd. was washed out after 19” of rain fell in October of 1996. Nearly 3,000 cubic yards of spoil material and riprap that was deposited was carefully removed from over 2 acres of the marsh surface. The Mill Brook project has restored 380 acres of marsh functions through plugging ditches, breeching a berm and removing invasive plants. A site walk along Mill Brook, post-restoration, will reveal more functional, shallow pools holding water at low tide.
Ongoing projects include resolving an issue of tidal restriction at an undersized culvert along the Libby River. Increasing tidal flow at this site will allow greater salinity upstream and along with herbicide treatments, discourage the establishment of phragmites. The Libby River has 27 acres of this invasive plant. The Nonesuch River project will begin in June of 2006. Restoration of this 247-acre marsh will entail the plugging of ditches, removal of berms and removal of phragmites. The 135-acre Dunstan River Marsh, bisected by U.S. Route 1, is considered by many to be the most degraded part of Scarborough Marsh. This site has been chosen as the recipient of mitigation funds resulting from the 1996 Julie N oil spill occurring in Casco Bay. These funds will partly cover the cost of restoration, which will include reducing the elevation of the marsh north of U.S. Route 1, dredging existing channels to increase the flow of salt water upstream of the highway, create a perimeter ditch to reduce fresh water intrusion from the uplands, create 15 shallow pools and eradicate over 30 acres of phragmites that has colonized the upstream side of the marsh.
The ultimate goal of the restoration is to return the marsh to a more functional ecosystem that provides diverse habitats of native vegetation and hydrology. There is still much to learn about the complexities of salt marsh restoration, but two guiding principles are well accepted by resource professionals; provide conditions permitting salt water to do the work nature intended and minimize anthropogenic pollution such as chemical contaminants, excess sedimentation and freshwater runoff. These two principles are especially significant considering the extent of tidal flow barriers and the rapidly developed uplands immediately adjacent to Scarborough Marsh.
