Seagrass - Salt
Marsh - Anadromous
|Researcher surveying restored
eelgrass bed using line-intercept/quadrat method.
F. Short, courtesy of NOAA
Monitoring of eelgrass transplant or seeding projects
focuses on quantitatively estimating the degree of transplant success
(Moore and Orth 1982; Phillips and Lewis 1983; Orth et al. 1994;
Fonseca 1994; Fonseca et al. 1987a, 1998). A secondary
objective of an eelgrass transplant monitoring program is to ascertain
the recovery of ecosystem function and community structure that
has been achieved, in comparison to natural eelgrass beds. This
typically involves collecting data on water quality and nutrient exchanges
within the beds, colonization of the bed by epiphytic and benthic
organisms, and use of the bed by fishery species (Thayer et al.
1975; Homziak et al. 1982; Hoffman 1988; Smith et al. 1989; Fonseca
et al. 1990, 1998). Recommendations for monitoring frequency, and
data interpretation techniques are provided by Fonseca (1994), and
Fonseca et al. (1998).
Suggested parameters to be monitored at eelgrass restoration and
reference sites include:
As a local example, basic monitoring costs for the eelgrass restoration
component of the U.S. Army Corps of Engineers New England District (USACE-NED) South Shore Habitat Restoration study
(presumably just percent coverage per recolonization surveys) are estimated
at $45,000 for the first year, and $15,000 per year for the next
Duration of Monitoring
Availability of funds and resources often limits the duration for
which seagrass restoration projects can be monitored, however the
duration and frequency of monitoring must be sufficient for a determination
of functional equivalency with reference or donor beds. Three to
five years of annual monitoring is considered a minimum level of
effort (USACE-NED 2002). Considerably longer monitoring periods
are likely to be necessary to document complete coalescence and
succession of transplanted areas. Some transplanted areas may never
achieve levels of coalescence comparable to that of natural beds
The principles of Adaptive Management have been incorporated into
the administration of habitat restoration projects within a variety
of governmental funding authorities and programs (Thom
1997). Comprehensive, long-term monitoring is a component of adaptive
management, which relies on the accumulation of evidence (via long-term
monitoring) to support a decision that demands action. If established early in the project-planning phase
and implemented during successive monitoring and management phases,
adaptive management can be a powerful method to systematically assess
and improve the performance of restored ecosystems (Thom 2000).
A well-designed restoration monitoring program will allow project
managers to detect deviation from projected results months, years,
or decades following construction. For example, monitoring of a
transplanted eelgrass bed might reveal the presence of seasonal
algal blooms which reduce available light, or evidence of grazing or disturbance.
Corrective measures such as supplemental transplants or the installation
of cages to exclude grazers might be necessary to maintain the integrity
of the transplant site.
Monitoring data can be used by project managers to demonstrate
the ability of the project to meet stated goals and objectives.
This is especially important in promoting the benefits of eelgrass
restoration to funding agencies, potential partners or sponsors for
future restoration projects, and the general public. Finally, long-term
monitoring data allows managers to learn from early projects, and
avoid potential pitfalls in successive restoration efforts (Thom
and Wellman 1997).
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Fonseca, M.S. 1994. A guide to transplanting seagrasses in the
Gulf of Mexico. Texas A&M University Sea Grant College Program,
TAMU-SG-94-601, College Station, Texas.
Fonseca, M.S., W.J. Kenworthy, D.R. Colby, K.A. Rittmaster, and
G.W. Thayer. 1990. Comparisons of fauna among natural and transplanted
eelgrass Zostera marina meadows: criteria for mitigation.
Marine Ecology Progress Series 65:251-264.
Fonseca, M.S., W.J. Kenworthy, and G.W. Thayer. 1987a. Transplanting
of the seagrasses Halodule wrightii, Syringodium filiforme,
and Thalassia testudinum for sediment stabilization and
habitat development in the southeast region of the United States.
Technical Report EL-87-8, U.S. Army Engineer Waterways Experiment
Station, Vicksburg, Mississippi.
Fonseca, M.S., W.J. Kenworthy, and G.W. Thayer. 1998. Guidelines
for the conservation and restoration of seagrasses in the United
States and adjacent waters. NOAA Coastal Ocean Program Decision
Analysis Series No. 12. NOAA Coastal Ocean Office, Silver Spring,
Hoffman, R.S. 1988. Fishery utilization of natural versus transplanted
eelgrass beds in Mission Bay, San Diego, California, pp. 58-64. In: Proceedings
of the California Eelgrass Symposium. Chula Vista, California.
Homziak, J., M.S. Fonseca, and W.J. Kenworthy. 1982. Macrobenthic
community structure in a transplanted eelgrass meadow. Marine
Ecology Progress Series 9:211-21.
Moore, K.A. and R. J. Orth. 1982. Transplantation of Zostera
marina L. into recently denuded areas, pp. 92-148. In: R.J.
Orth and K.A. Moore, (eds.), The Biology and Propogation of
Zostera marina, eelgrass, in the Chesapeake Bay, Virginia.
Special Report No. 265 in Applied Marine Science and Ocean Engineering,
Virginia Institute of Marine Sciences, Gloucester Point, Virginia.
Orth, R.J., M. Luckenbach, and K.A. Moore. 1994. Seed dispersal
in a marine macrophyte: implications for colonization and restoration.
Phillips, R.C. and R.R. Lewis, III. 1983. Influence of environmental
gradients on variations in leaf widths and transplant success in
North American seagrasses. Marine Technology Society Journal
Smith, I., M.S. Fonseca, J.A. Rivera, and K.A. Rittmaster. 1989.
Habitat value of natural versus recently transplanted eelgrass,
Zostera marina, for the bay scallop, Argopecten irradians.
Fishery Bulletin 87:189-96.
Thayer, G.W., S.M. Adams, and M.W. LaCroix. 1975. Structural and
functional aspects of a recently established Zostera marina
community. pp. 518-540 in: L.E. Cronin (Ed.) Estuarine Research.
Academic Press, New York, New York.
Thom, R.M. 1997. System-development matrix for adaptive management
of coastal ecosystem restoration projects. Ecological Engineering
Thom, R.M. 2000. Adaptive management of coastal ecosystem restoration
projects. Ecological Engineering 15:365-372.
Thom, R.M. and K.F. Wellman. 1997. Planning aquatic ecosystem restoration
monitoring programs. Evaluation of Environmental Investments Research
Program, U.S. Army Corps of Engineers Institute for Water Resources,
IWR Report 96-R-23, Alexandria Virginia.
U.S. Army Corps of Engineers New England District (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.
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