- Salt Marsh - Anadromous
Salt marsh restoration has received much attention in coastal engineering.
This is likely due to the considerable acreage of salt marsh that
has been lost along U.S. coastlines, recent recognition of the important
functions provided by salt marshes, and the relative ease in which
tidal marsh vegetation can be propagated at restored sites. It is
important to distinguish between "restoration" and "creation"
of coastal habitats, although the two terms are sometimes used interchangeably.
Restoration generally refers to projects in which an area
is returned to a close approximation of some natural or known historical
condition. In salt marshes, this may involve removal of dikes, berms,
and fill material, or installation of culverts under roadways to
reestablish the historic tidal flows. Marsh creation is
often a component of the restoration process, especially in projects
involving the removal of fill and/or regrading of adjacent uplands
to intertidal elevations.
Site Selection | Goals
& Objectives | Baseline Data | Funding
It is important to carefully consider and prioritize the selection
of salt marsh restoration sites. Because funds for restoration are
limited, it is essential that the site selection process generates
a list of alternatives that offer the best chance of achieving the
greatest output, both in terms of acreage restored, and the degree
of function achieved.
A proposed salt marsh restoration project should:
- Be consistent with the geography and land-use patterns of the
- Avoid or minimize negative impacts to existing aquatic and terrestrial
habitats in the vicinity of the restoration area, including plants
and animals, and historic resources.
- Address the concerns and desires of the local community.
- Be consistent with federal, state, and local regulatory agency
requirements and policies.
Analyses of current and projected land-use patterns, and socioeconomic
factors are necessary and may be a critical factor in the final selection
of possible restoration sites. Cooperation from landowners and
municipalities, and the development of a positive public perception
of habitat restoration are necessary to achieve success on a landscape-level
scale (USACE-NED 2002).
There are several efforts currently underway in Rhode Island to
develop methods of identifying, prioritizing, and selecting sites
at which to conduct salt marsh restoration. The Narragansett Bay
Reverse Trends Analysis Project is a cooperative project among the
Rhode Island Department of Environmental Management's Narragansett
Bay Estuary Program (NBEP), the University of Rhode Island's
Environmental Data Center, the U.S. Fish and Wildlife Service (USFWS),
and the University of Massachusetts' Natural Resource Assessment
Group. The project is developing planning tools for habitat restoration
in Narragansett Bay. The trend analysis involves careful interpretation
of aerial photography over a long time scale (decades) to measure
historical changes in wetland loss and determine accurate acreage
NBEP is developing a Geographic Information Systems (GIS)
database and maps showing the locations of potential restoration
sites throughout Narragansett Bay. The GIS database and maps will be used
by coastal managers to prioritize habitat restoration projects in
Narragansett Bay. The NBEP is also mapping critical habitat resources
in Narragansett Bay. This process began with the formation of an
aquatic habitat mapping subcommittee, with representatives from
academia, federal and state agencies, and non-governmental organizations
(NGO). The committee will evaluate existing maps and plan
future mapping projects. The current focus is on eelgrass and salt
A salt marsh habitat siting tool for Narragansett Bay is in development
and will be available from this Web site. This GIS-based model will
use the wetland data developed by NBEP and will include ecological
and socioeconomic data. More details on the tool and its availability
for use in restoration planning can be accessed in the Salt
Marsh Site Selection Tool section.
A considerable number of potential locations for salt marsh restoration
are present throughout Narragansett Bay and along Rhode Island's
South Shore. Evaluation of site-specific factors (e.g., presence
of invasive plant species, history of dredged material or other
fill placement, hydrologic restriction, ownership, adjacent land
use, etc.) would result in a prioritization or ranking of potential
sites to be considered for funding. The Salt Marsh Site Selection Tool
can be a valuable aid in the site screening and prioritization process.
Defining Project Goals and Objectives
It is important to determine the goals and objectives of a salt marsh
restoration project at the outset. Salt marsh restoration projects
that lack clearly defined goals and objectives are less likely to
achieve success, and in many cases it may be impossible to gauge
success in the absence of a clearly defined project plan. Clear
goals and objectives assist in communicating restoration plans to
potential funding sources, agency partners, and the general public.
Project goals refer to the ecosystem attributes to be restored,
such as water quality, hydrology, plant communities, or fish and
wildlife resources. Goals are general statements about the desired
project results, and provide a general framework for the project.
An example goal for a salt marsh restoration project might be to
"restore the native plant community (e.g., Spartina
species) and limit the presence of invasive species (e.g.,
Project objectives are more precise, and may include the specific
characteristics of water quality, hydrology, or plant and animal
communities to be restored. Performance indicators are developed
during the life of the project and represent measurable characteristics
such as nitrogen concentration in soil porewaters, Phragmites
height and stem density, or the number of killifish per unit area
of marsh surface. Performance indicators are quantitative, and are
used to determine whether or not a salt marsh restoration project
will meet predetermined success criteria. These are the targeted
outputs, which are agreed upon and developed by a team consisting
of the project's proponents and any outside experts or consultants.
For example, if the goal of a project is to reduce or eliminate
Phragmites, the success criteria might be the number of
acres of marsh that have been recolonized by Spartina
species at 3, 5, and 10 years post-restoration. The failure of a project
to meet these acreage targets would be cause for reevaluation and
perhaps, implementation of corrective measures at the site (Pastorok
et al. 1997, Weinstein et al. 1997).
Environmental factors to be considered in the formulation of goal
statements or project objectives include hydrologic conditions,
surrounding land-use patterns, connectivity to natural wetlands
or other adjacent ecosystems, and evaluation of various wetland
functions. Enhancement of certain functions (e.g., habitat
for estuarine-dependent fisheries) may be a primary objective of
many salt marsh restoration projects; however, designing a project
to maximize the output of one particular function may involve a
trade-off with other functions (e.g., bird and wildlife habitat
or shoreline stabilization).
Baseline Data Collection
Detailed site characterizations are needed to formulate site-specific
restoration plans and to develop success criteria for individual
projects. Examples of baseline data that are collected during pre-restoration
baseline surveys may include:
- surface topography and elevation
- water table depth
- surface water level
- surface and groundwater quality
- soil organic matter and water content
- plant species distribution and cover
- benthic invertebrate communities
- utilization of the marsh by finfish and crustaceans
- utilization of the marsh by wildlife
For more details on how these data are collected, please see Habitat
Many of these parameters are included in some of the standardized
wetland assessment methods that have been developed by the U.S.
Army Corps of Engineers (USACE), USFWS, and other agencies. For
example, the USFWS Habitat Evaluation Procedure (HEP) requires
input of data on select animal species that could potentially benefit
from the cover available at a particular site (e.g., a salt marsh
slated for restoration). Numerical models are constructed to evaluate
the variables which determine habitat suitability for a particular
species. The outputs of the procedure are habitat suitability of
each cover type identified and the entire study area for the desired
species (USFWS 1980, Bartoldus 1999).
The USACE and other federal agency partners are currently developing
the Hydrogeomorphic Approach to Assessing the Function of Wetlands.
This method is being developed to assist in the evaluation of wetland
impacts under the USACE's Section 404 Regulatory Program, and to
assist in the planning of restoration projects that may be outside
the realm of Section 404. The Hydrogeomorphic Approach, like HEP,
is also based on numerical modeling and relies on data inputs on
a variety of topics, including surface and groundwater hydrology,
sediment stabilization and shoreline erosion, wetland plant community
structure, fish and invertebrate communities, and wildlife utilization
(Brinson 1993, Shafer and Yozzo 1998, Bartoldus 1999).
Additional methods, often developed on a state-by-state basis, combine
aspects of functional assessment with societal indicators, integrating
ecological and human values into a single assessment procedure.
A local example is the Narragansett
Bay Method, recently developed by Save The Bay. This assessment
protocol has been adapted from a number of coastal wetland assessment
techniques and has been used to characterize the health and ecological
integrity of salt marshes throughout Rhode Island. Volunteers have
been used to conduct many of the assessments. The specific emphasis
of the Narragansett Bay Method is to determine the extent to which
salt marshes have been impacted by human activities (Save The Bay
The costs of restoration are largely dependent on site-specific
conditions and the types of restoration and monitoring activities
planned for a project (see Cost Analysis
for details). A variety of federal, state, and private funding opportunities
are available to support salt marsh restoration in Rhode Island.
These funds are available to a wide range of organizations, including
state and local agencies, private landowners, and NGOs. A comprehensive
list of funding opportunities for salt marsh restoration in Rhode
Island is available from this site in the Funding
Restore America's Estuaries (RAE), a non-profit organization dedicated
to preserving estuaries throughout the U.S., has developed an on-line
electronic database called Funding
for Habitat Restoration Projects: A Citizens Guide. The guide
is intended to help individuals, organizations, and agencies access
federal assistance in support of community-based habitat restoration.
The database can be queried by program, agency, or funding amount.
Permitting and Regulatory Considerations
Agencies, NGOs, or individuals proposing the restoration of
salt marshes in Rhode Island must secure a variety of permits prior
to construction of the project. A USACE Clean Water Act section
404 permit and a DEM freshwater wetlands permit or Coastal Resources
Management Council (CRMC) permit, depending on the jurisdiction
within which the proposed project is located, may be required. A
DEM water quality certification is required for all coastal habitat
projects that result in the discharge of dredged material or fill
into state waters. A Federal 401 water quality certification may
also be required.
Salt marsh restoration projects that involve application of herbicides
to control invasive plants (e.g., Phragmites)
would require permission from the DEM Division of Agriculture. All
salt marsh restoration projects conducted in Rhode Island must be
evaluated by DEM for consistency with the state's Coastal
Zone Management (CZM) program. Evaluation of a proposed salt marsh
project by the U.S. Environmental Protection Agency (EPA), the National Marine Fisheries Service (NMFS), and USFWS would be conducted through review
of the USACE Section 404 Permit.
A list of specific information required to complete a programmatic
general permit application and a copy of the CRMC permit application
is available in the Permitting Process
section of this Web site.
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Bartoldus, C.C. 1999. A comprehensive review of wetland assessment
procedures: A guide for wetland practitioners. Environmental Concern,
Inc., St. Michaels, Maryland.
Brinson, M.M. 1993. A hydrogeomorphic classification for wetlands.
Wetlands Research Program Technical Report WRP-DE-4. U.S. Army Corps
of Engineers, Waterways Experiment Station, Vicksburg. Mississippi.
Pastorok, R.A., A. MacDonald, J.R. Sampson, P. Wilber, D.J. Yozzo,
and J.P. Titre. 1997. An ecological decision framework for environmental
restoration projects. Ecological Engineering 9:89-107.
Save The Bay. 2002. "Narragansett Bay Method" Web page (http://www.savebay.org/bayissues/narr_bay_method.htm).
Shafer, D.J., and D.J. Yozzo. 1998. National guidebook for application
of hydrogeomorphic assessment to tidal fringe wetlands. Wetlands
Research Program Technical Report WRP-DE-16, U.S. Army Corps of
Engineers, Waterways Experiment Station, Vicksburg, Mississippi.
USACE-NED. 2002. Rhode Island South Shore Habitat Restoration Feasibility
Report and Environmental Assessment (Draft). U.S. Army Corps of
Engineers, New England District, Concord, Massachusetts.
USFWS. 1980. Habitat Evaluation Procedure (HEP) Manual (102 ESM).
U.S. Fish and Wildlife Service, Washington, D.C.
Weinstein, M.P., J.H. Balletto, J.M. Teal, and D.F. Ludwig. 1997.
Success criteria and adaptive management for a large-scale wetland
restoration project. Wetlands Ecology and Management 4:111-127.
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This site was created through
a partnership of the:
Coastal Resources Management Council
Narragansett Bay Estuary Program
Save The Bay®