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Lower Fore River Sanctuary

Welcome to the Lower Fore River Sanctuary!

Visiting the wetland

The Fore River Sanctuary is part of Portland Trails, which makes it open to the public every day from dawn to dusk. It is dog-friendly (as long as the dog is on a leash). Access to the south end is reached by parking at Maine Orthopedics on 1601 Congress Street and following the path to the Portland Trails sign (Portland Trails, 2012).

If you're planning a trip to the Fore River Sanctuary, wear boots!

click here to see pictures of Fore River Sanctuary in Google Earth

General Information

Located right off of outer Congress Street, The Fore River Sanctuary is an 85-acre wetland preserve. The area is the former site of the beginning of the Cumberland and Oxford Canal. This manmade feature was utilized to transport materials to and from Portland to inland communities during the 1800’s before the construction of major highways. The canal met up to the Presumpscot River in Westbrook and from there followed the river to Sebago Lake. The total length of the canal was approximately 38 miles. Remnants of the canal can still be seen along the Fore River Sanctuary when using the walking trail (Portland Trails, 2012).

It was determined that the Fore River Sanctuary is a Spartina Salt Marsh due to the predominance of S. alterniflora along the tidal creeks and S. patens virtually dominating the open vegetation in abundance. However,  bands or patches of other grasses were found as well as Salicornia spp. among the sea of S. patens.
Around the margins of the wetland display characteristics of a mixed forb-herb salt marsh and further inland the marsh displays certain brackish tidal marsh characteristics. The
Fore River Sanctuary is not a pristine Spartina
salt marsh.
The marsh has experienced many manmade environmental alterations including the construction of a railroad through the middle of the marsh as well as a walking trail around the edges of the marsh. Due to the proximity of suburban neighborhoods and urban development, it is likely that the Fore River Sanctuary has been impacted by urban runoff. Due to the construction of a railroad through the middle and a walking trail around the wetland, other environmental conditions such as filling in the land to increase elevation, have been introduced to the system which has resulted in other plants, sometimes terrestrial, thriving in the area where, without these manmade alterations, they would not be there.

The land was donated to Portland Trails by Tom Jewell, one of the founders of Portland Trails. Within the Fore River Sanctuary are a number of
different wetland types as defined by the National Wetlands Inventory.

A Spartina Salt marsh has a state rarity ranking of S3 which means that it is rare in
 Maine, which equates to about 20-100 occurrences (Gawler and Cutko, 2010; Tiner, 1991;
USDA, 2012).

Wetland characteristics


When researching the soils of the Lower Fore River Sanctuary, only the tidal marsh (Tm) soils are considered hydric. Hydric soils, as defined by the National Technical Committee for Hydric Soils (NTCHS), are “soils formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions (Federal Register, 1994).”  Under normal conditions, these soils are so continually saturated with water that growth of hydrophytic vegetation is inhibited. Tidal marsh soils are usually wet, very compact and display a thick almost clay-like texture.


The various hydrologic parameters monitored include: depth to water table, flooding frequency, ponding frequency, and runoff potential. Depth to water table refers to the saturated zones in the soil.The various depths to water table fluctuate on a normal basis and are only specified for certain months. The depths are estimated based on visual observations, specifically redoximorphic features (grayish colors) of the soil.Flooding frequency is the temporary inundation of an area that is caused by either overflowing streams, increased runoff, or tides. Ponding frequency refers to the frequency of standing water located in closed depressions. These ponds are removed through percolation, transpiration, and evaporation.


Research was done to identify the general type of wetland the Fore River Sanctuary is, as well as what types of vegetation were expected to be found in this wetland. It was determined that the Fore River Sanctuary was generally considered a coastal tidal salt marsh. A coastal marsh generally consists of mostly grasslands that are periodically flooded by salt or brackish water. The flood levels occur at various levels depending on tidal action. The flooded areas may be flooded as frequently as daily to as infrequently as once or a few times a year (Federal Register, 1994). When these areas are not flooded, the soil will remain saturated with water near the surface. The salt brought in from the ocean results in a very stressful environment for most plants to grow. As a result, most of the plants found in coastal salt marshes are plants that have developed adaptations for dealing with salt water environments. These plants are referred to as halophytes. Halophytes can grow in both freshwater and saltwater environments but are outcompeted in freshwater systems and as a result
are mostly found in saltwater environments (Tiner, 1991)

It was observed that trees over 10 feet tall formed less than 30% of cover. Some trees were present but the wetland consisted mostly of open vegetation. The soils were saturated and seasonally flooded by tidal creeks. The major components of the lower portion of the wetland were cordgrasses. Moving inland and upland, cordgrasses become less dominant and a mixture of graminoids and forbs become present. The majority of vegetation present was dried dead material from the previous growing season. However, new growth was consistently observed in the wetland as well as the surrounding area. The undisturbed plains of the wetland around the tidal creeks consisted mostly of S. patens and S. alterniflora. A clear zonation pattern between S. alterniflora and S. patens was observed along the tidal creeks. Green algae were seen growing along the high tide line of the tidal creeks. The diversity of the vegetation increased as the wetland increased in elevation or came closer in proximity to the Fore River Sanctuary trail and the railroad. A variety of terrestrial plants were found on the manmade walking trail and the railroad as the trail was elevated

above the water table. During the site visit, geese and ducks were spotted in the wetland. No amphibians were seen. A number of macroinvertebrates were seen in the wetland including spiders and crickets. Mosquito larvae were seen in one of the salt pannes. On previous visits to the wetland last fall, mummichogs were seen in a salt panne. However on this visit, no mummichogs were seen.

Julie N oil spill 1996

A preassessment data report was compiled by Industrial Economic, Inc. in 1998 for the Maine Department of Environmental Protection in 1998 to assess the environmental impacts of the Julie N oil spill in Portland Harbor. In September of 1996, an oil tank vessel named the Julie N coming into Casco Bay struck the Million Dollar Bridge and approximately 179,634 gallons of oil were spilled into Portland Harbor. The oil traveled up the Fore River to the Fore River Sanctuary and negatively impacted the surrounding nearshore estuarine systems. Under the Oil Pollution Act of 1990, it was required that a Natural Resource Damage Assessment (NRDA) be conducted to determine the extent of the environmental damage. They found a total of 25.61 acres of S. alterniflora wetlands were mainly impacted by the oil spill, and 14.65 acres were moderately or heavily oiled. Other impacts of the spill include changes in sediment quality, water quality, finfish and shellfish communities, bird populations, and benthic organisms. The spill also resulted in various socioeconomic impacts such as temporary decreased tourism and recreational boating and fishing in Casco Bay (Reilly, 1998).


Federal Register. (July 13, 1994). Changes in hydric soils of the United States.

Gawler, S. and Cutko, A. (2010). Natural Landscapes of Maine: A Guide to Natural Communities and Ecosystems. Maine Natural Areas Program, Maine Department of Conservation, Augusta, Maine: ONLINE Natural Areas Key: http://www.maine.gov/doc/nrimc/mnap/features/communitykey.htm

Portland Trails. (2012). Portland Trails: Nonprofit Urban Land Trust. About Fore River Sanctuary. URL:
http://trails.org/our-trails/fore-river-sanctuary/ (accessed February 20, 2012).

Reilly, T. J. (1998). Julie N Preassessment Data Report. Prepared for Maine Department of Environmental Protection, Maine Department of Conservation, Maine Department of Inland Fisheries and Wildlife, Maine Department of Marine Resources, National Oceanic and Atmospheric Administration, and U.S. Department of the Interior. Industrial Economics, Incorporated, Cambridge, MA.

Tiner, R. W. (1991). Maine Wetlands and Their Boundaries: A Guide For Code Enforcement Officer. Prepared for the State of Maine Department of Economic and Community Development Office of Comprehensive Planning, Augusta, ME, June 1991.

Web Soil Survey. (2012). United States Department of Agriculture: Natural Resources Conservation Service - Web Soil Survey. URL: http://websoilsurvey.nrcs.usda.gov/app/ (accessed March 29, 2012).

USDA, NRCS. (2012). The PLANTS Database (http://plants.usda.gov, 1 April 2012). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Wetland information and photos by Miguel Barajas, Department of Environmental Science, 2013. Last updated on 04/26/2012 by MB