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How Healthy is Your Salt Marsh

How Healthy is Your Salt Marsh?

A healthy salt marsh is a complex ecosystem delicately balanced between the marine and terrestrial environments. It appears as a flat, low growing, meadow of lush, salt tolerant, grasses. A system of meandering creeks distributes tidal water throughout a healthy salt marsh. Because they are intimately associated with tidal waters, salt marshes in New Hampshire are only found along the coast and around the Great Bay estuary. There are about 6,200 acres of salt marsh in New Hampshire.


Conservationist in a New Hampshire salt marshWhy are healthy salt marshes important?

Healthy salt marshes provide many important values to the residents of New Hampshire's coasts. They are habitats for fish, birds, and other wildlife. Some wildlife species such as sharp-tailed sparrows are only found in healthy salt marshes. Salt marshes are a major feeding grounds for snowy egrets and great blue herons.

Salt marshes also function to improve the water quality of coastal waters. Salt marshes are visually attractive and provide much of the open space along the coast. Healthy marshes breed fewer mosquitoes than deteriorating marshes. Unhealthy salt marshes can subside or erode away, leaving muddy basins.

How do salt marshes get sick?

A healthy salt marsh has several requirements including sufficient tidal flow. In some places tidal flow is blocked by roads, railroads, and other obstructions. Even where culverts and bridges have been installed, the opening may be too small to allow adequate flow. The photograph below shows a restrictive road culvert which is too small to allow adequate tidal flow.

Picture of restricted tidal flow through an inadequate culvert.The invasive species Phragmites, growing high in a degraded salt marsh.Another common problem with salt marshes are ditches which were dug in the past in a failed attempt to reduce mosquito populations. Often, attempts to drain and manipulate marshes actually resulted in more mosquitoes not less.

A sick salt marsh may become choked with common reed (Phragmites australis) as shown in the photograph above right. Phragmites and other plants such as purple loosestrife (Lythrum salicaria) which invade unhealthy marshes have very low value for wildlife and may crowd out more beneficial plants.

The photo below shows aerial views of a salt marsh in New England with meandering tidal creeks that provide salt water to all parts of the marsh.  It is the salt water that is the life blood of a salt marsh, as it limits the growth of species other than naturally adapted salt marsh vegetation. 

Aerial view of a New England salt marsh with tidal creeks.How can you help?

First, learn about the importance of keeping salt marshes healthy. There are plenty of opportunities, just call one of the offices listed below. Help educate your neighbors about the significance of salt marshes to the ecology of New Hampshire's coast.

Second, learn to use the tools available to help you evaluate the potential for restoring salt marshes in your community such as methods and brochures on our Ecosystem Restoration web site.

Students working with an NRCS engineer on salt marsh restoration.Third, volunteer to take an active role in salt marsh evaluation, monitoring, and restoration. Many coastal towns in New Hampshire are getting involved in maintaining the health of our coastal marshes. There are opportunities for citizens to participate in ongoing restoration and monitoring of salt marshes in New Hampshire.

Who do you contact?

Your town Conservation Commission or:

Natural Resources Conservation Service
Federal Building, 2 Madbury Road
Durham, NH 03824-1499
(603) 868-7581

Audubon Society of New Hampshire
3 Silk Farm Road
Concord, NH 03301

NH Department of Environmental Services
Coastal Program
NH Coastal Program
Watershed Management Bureau
Department of Environmental Services
PO Box 95
Concord, NH 03302-0095

(603) 271-8811

Great Bay National Estuarine Research Reserve
NH Fish and Game Region 3
225 Main Street
Durham, NH 03824
(603) 868-1095


More on Salt Marsh Restoration in New Hampshire