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Dunstan River, Scarborough Marsh

Dunstan River Winter 2012

Welcome to the Dunstan River Tidal Salt Marsh Wetland in Scarborough, Maine!

Dunstan River is one of the five rivers that comprises Maine's largest contiguous Tidal Salt Marsh--the Scarborough Marsh. Tidal marshes are the most productive type of wetland (Wilson, 2012).


Using the Marsh for haying purposes declined in the 1900s and many residents thought of the marsh as a wasteland and an inexpensive place to fill and build. In 1957, the Maine Department of Inland Fisheries and Wildlife (MDIFW) started a twenty-year process of acquiring the marsh.  The partnership between Maine Audubon and MDIFW formed in 1972, utilized efforts to create a nature center at the edge of the marsh on Rt. 9. In 2000, the Friends of Scarborough Marsh was formed by volunteers and representatives for town, state and federal commissions. The Friend’s mission is dedicated to the conservation, protection, restoration and enhancement of the wetland’s watershed.

Wetland Characteristics

Scarbourough Marsh Maine Audubon Sign

  1. Soils-- The Dunstan River exhibits a majority of Tidal Marsh Soils.
  2. Hydrology-- The Dunstan River experiences constant shifts in hydrology due to daily tides.
  3. Vegetation-- The Dunstan River is home to a variety of salt-marsh plants; namely grasses. Native grasses is Smooth Cordgrass (S. alternaflora) in low elevation marsh parts and  Salt hay (Spartana patens) in high elevation marsh parts, that are not as frequently flooded and less salty.
  4. Wildlife-- The Dunstan River is critical habitat for many migratory waterfowl that come to Maine.
  5. Other Interesting Facts
    • In the early 20th century people believed that draining salt marshes would result in reducing mosquito populations. ACTUAL RESULT: Less killifish, a mosquito predator, habitat and therefore mosquito population growth.

Visiting the Wetlands

There are many activities to do at this tidal marsh for people and pets (on leashes!) throughout the year. The summer time, true most anywhere in Maine, is the busiest. Driving, motorbiking, biking, walking/running, canoeing (upland from the Barrier Beach) are all encouraged around the Marsh to get people engaged in this unique and highly productive ecosystem.

Directions to Dunstan River:


          Southbound— 295: Take Exit 2 towards South Portland/ Scarborough. Merge onto US Route One. Follow Route One, driving over the Dunstan River, come to the junction with Pine Point Rd/9 at Dunstan Corner (use Dairy Corner as landmark). Take left onto Pine Point Rd/9 and continue on to access point.

                Northbound—95: Exit 42 towards Scarborough. Look for signs towards US Route One. Head north on Route One. Come to stoplight junction with Pine Point Rd/9 at Dunstan Corner(use Dairy Corner as landmark). Turn right onto Pine Point Rd/9 and continue onto access points.

ice on dunstan river

Wetland information and photos by Lorraine K Rudolph, Department of Environmental Science, 2012. Last updated on 05/14/2012 by LKR.