Richard C. Lewis

Abstract: The objective of this proposal is to recreate a salt marsh in Riverside Park, in the Manhattan borough of New York City. Before Europeans began intensively settling Manhattan about four centuries ago, the island was ringed with tidal marshes. Yet today, only 196 acres of these critical ecosystems remain (City of New York Department of Parks & Recreation 2001). This paper outlines how to reintroduce wetlands in Manhattan by establishing a pilot, three-acre salt marsh, with the hope that its success would inaugurate a chain of restored, linked marshes along the western side of the island.

 

Salt marshes yield ecological benefits that have been well documented. They provide shoreline stabilization, erosion mitigation, runoff water filtration and groundwater recharge. They have important biotic contributions as well, serving as spawning grounds for fish and other marine organisms, stopover points for migratory birds and shelter for other animals. While salt marshes do not house a wide variety of species assemblages (species richness), they do tend to support thriving populations of species that are there (species abundance). They are, in short, biodiversity “builders” for certain species in a critical type of ecosystem that is diminishing.

 

The proposed project is ambitious. It would involve recreating a wetland in an area that is now parkland, with few, if any, characteristics of its past as a tidal area. It would involve the creation of partnerships among federal, state and local organizations, help from volunteers and perhaps private financial outlays and in-kind gifts. It would require expert engineering and construction to dredge the marsh, to build a channel connecting the marsh to the Hudson River estuary and to possibly create a water control structure system to buffer the marsh against strong tidal circulation. It would require hands-on management, to deter exotic species from entering and overwhelming an ecosystem that would be vulnerable at the outset and to monitor nitrogen flows from a major wastewater treatment plant located nearby.

 

But what an attraction this marsh would be. The benefits are indeed manifold. As already noted, the marsh would constitute habitat for a variety of fish and bird species, and provide an important stopover point for migratory fowl between the New Jersey Meadowlands and the Jamaica Bay estuary, both substantial, though impaired wetlands. There is little debate that more such resting, breeding and nesting areas are needed. The hydrologic functions of salt marshes also have been described.

 

In addition, the marsh would be used for research, the ultimate urban laboratory for conducting experiments of emerging hypotheses in restoration ecology – by so many scientists who call New York City home. The marsh would double as an educational center, introducing the wonders of ecology from elementary schoolchildren to the elderly. An environmental exhibit center, located on site, would bring those educational benefits to life. The wetland would offer passive recreation opportunities and aesthetic enjoyment to city residents and tourism potential for out-of-towners. In short, it would offer something for everyone, just the way New Yorkers would have it.

 

If it succeeds, the pilot marsh could inaugurate the creation of a chain of marshes running along the west side of Manhattan to the George Washington Bridge and perhaps beyond. The environmental benefits of such a string of marshes would be tremendous, akin to achieving economies of scale for the environment.

 

Project Location and Description

 

The project location would be in a section of Riverside Park located approximately ½ mile north of the North River Wastewater Treatment Plant, which is located between West 137^th and West 145^th streets. The suggested size of the project area is three acres.

 

The physical characteristics of the area consist of a park, with a walking/biking path, a patio overlook area along the river and two parking lots that sandwich a grassy area. At the southern boundary is the Ten Mile River playground. At the northern end are two volleyball courts that appear to be heavily used. The river comprises the western end, while the four-lane Henry Hudson Highway (Route 9A) makes up the eastern boundary.

 

Starting from the river and moving east, there is a section of riprap that extends about 20 feet from the shoreline into the Hudson. Proceeding inland and adjacent to the riprap is a cobblestone patio area with four rows of benches, paired so as they face each other in a north-south direction (so facing parallel to the river rather than facing out toward it). The patio area morphs into the walkway/bike path, which is part of the Riverside Park path that extends along most of the Manhattan’s west side. Next to the path are two parking lots. In between them is a grassy area that shows signs of soil compaction, with many bare patches, most likely caused by people’s use of the area. There are scattered trees in the area, confined mostly to the perimeter of the site.

 

Area and Site History

 

It would be hard to overstate the Hudson River’s historical significance and its value to New York State and to the region. Humans had used the estuary for up to 10,000 years before Henry Hudson sailed the river and gushed about its abundance of fish and other wildlife in his journal in 1609. More than 200 species of fish call the Hudson home, including Atlantic and shortnose sturgeon, striped bass, American shad and blue crabs. (New York State Department of Environmental Conservation 2005)

 

Also, the Hudson is the northernmost latitude for various tropical fish, which glide in on the Gulf Stream during the warmer months. In short, the Hudson offers an extensive menu of nature’s maritime bounty.

 

Yet the river and the wetlands that lined its shores have changed dramatically since full-scale settlement began about four centuries ago. In the general project area, the marshes have been filled to build roads, railroad lines, businesses and housing. More recently, the city’s parks and recreation department have reclaimed more of the land running along the river, to connect and extend the Riverside Park system. This effort is to be commended, but it is fragile, for in many areas the strip of green is narrow and vulnerable.

 

Still, the park has brought people back to the river, and it seems they like what they see. On many days, scores of people exercise, play, picnic and fish within yards of the river. There are exceptional places from which to gaze at the water, which has become cleaner and clearer. The Hudson is on the rebound, and people are enjoying its rebirth.

 

The Plan

 

Challenges

An enduring debate among restoration ecologists is whether a restored wetland can achieve similar functions as a natural wetland. Recent studies appear to be encouraging. A comparison of two constructed Spartina alterniflora marshes with two natural marshes in North Carolina showed the restored sites exhibited many of the key ecological functions as the natural areas, such as community structure, aboveground biomass and soil development. (Craft et al. 1999) However, soil organic carbon and nitrogen stores were much smaller after 25 years in the created marshes than its natural comparatives.

 

A study of three sites in South Carolina yielded promising results as well. There, researchers found that plant and infaunal communities at created marshes had “qualitatively similar overall species composition to natural marsh areas.” (Posey et al. 1997) A wide-ranging study comparing eight constructed marshes with eight natural marshes along the North Carolina coast showed that most of the created marshes reached equivalence with the natural areas five to fifteen years after construction, except for soil organic carbon and nitrogen pools, which were much lower after 28 years. (Craft et al. 2003)

 

On the contrary side, a man-made marsh in North Carolina “remained functionally distinct” from adjacent natural marshes after three years, a team of scientists noted, including sediment properties and infaunal community composition. (Moy and Levin 1991)

 

Time is another issue to consider. Recent studies have shown that re-created salt marshes can take years to achieve ecological resemblance to a natural marsh and that individual marshes do not develop at the same pace. (Craft et al. 1999; Craft et al. 2003; Posey et al. 1997) So, progress may be incremental and undiscerning to the unscientific observer, which could affect public judgment of the project.

 

Nitrogen loading from the North River wastewater plant may also be a concern. High levels of nitrogen concentrations in marsh sediment could have a detrimental effect on the marsh’s functioning and may lead to eutrophication. There will be more discussion on this topic under the monitoring and management section of this paper.

 

The presence and potential introduction of exotic species presents a real challenge. The Hudson is a carrier of a host of introduced species, mainly because of its use for shipping and its link to the ocean. Aggressive monitoring would be needed to help the young marsh to resist any invaders.

 

Monitoring will also be needed to ward off, to the extent possible, disturbance by humans. The marsh would be located nearly adjacent to the Henry Hudson Parkway and next to the Riverside Park bike path, and could be prone to anthropogenic influences.

 

Benefits

A recreated wetland in the middle of Manhattan holds numerous benefits. The main benefit is simply in its creation. It is widely known that salt marshes have been declining in the face of increased development and those that remain are becoming more stressed by anthropogenic influences such as pollution and disturbance. As stated in the abstract, salt marshes are incubators for a variety of species specially adapted to live in a saline environment. Indeed, more than one-third of federally endangered and threatened plants and animals require wetlands at some point during their life cycles (Muir 1990). Marshes provide hydrologic functions as well that benefit people, especially those in an urban environment. The positive impacts are better protection from flooding, erosion control and shoreline stabilization. Marshes also filter pollutants from runoff and help recharge the underground water supply.

 

Aside from its natural benefits, a primary goal for this project would be in research. The marsh could be the ultimate urban laboratory, the locus for leading scientists to test emerging hypotheses in restoration ecology. What better place to perform tests than New York City? As an example, the Hudson River Estuary Action Plan, an ambitious multi-agency collaboration to improve the river and watershed by 2009, includes a section to reestablish oyster beds and assure the sustainability of blue crabs. The marsh could be an excellent location to carry out such experiments.

 

Going hand-in-hand with its research mission, the marsh would be an educational center for students of all age levels and adults. Think of it as a living classroom. Elementary, secondary and collegiate classes would visit the marsh and learn first-hand of its importance to people and to nature. One idea is to build an environmental center on the grounds with exhibits, tours and interactive kiosks to deepen the educational experience. The location itself is a plus, too. It would be an oasis of nature in Harlem, an area long subjected to industrial placement, blight and a general ho-hum disregard by planners and policy makers.

 

The marsh also would provide recreational possibilities, inviting people strolling by on the Riverside Park bike path to admire the scenery. The area would be a lure for birders as well. There are certainly possibilities for tourism, as organizations could bill the area as New York City’s grand attempt to bring back an elemental feature of its past.

 

Lastly, the marsh could jumpstart the building of a chain of wetlands along Manhattan’s western shoreline, extending to the George Washington Bridge and beyond. Such a project would put New York City in the forefront of urban ecological restoration and establish the city as the model for successfully reintroducing wetlands in urban landscapes.

 

Creating the Marsh

The creation of the marsh would involve four main elements: creating the channel, dredging the area, grading and planting spartina.

 

The channel would link the Hudson with the marsh. Design surveys would be needed to establish the length of the channel, its width and depth to ensure adequate, but not overwhelming, tidal flows into the marsh. It would also be necessary to examine the wave energy, and configure the channel accordingly, such as reinforcing it with a higher bank at one end to absorb waves. Another method that should be examined to mitigate fetch and to regulate what may be strong tidal circulation in the constructed marsh is to design a water control structure. Save the Bay encountered this problem at its Providence site and constructed a stone wall running parallel to the marsh to minimize fetch and protect the spartina planting, with mixed results (Lewis 2006). The Riverside Park site, more like a cove connected to the Hudson by a channel, would have more natural protection than the Save the Bay site, which is located on the shore of a large expanse of open water. Still, such a structure may be needed to protect the Riverside Park marsh from debris floating in from the Hudson.

 

Dredging would be the primary method to create the marsh. Analyses would be needed to establish the scope of the operation and the ideal depth of the marsh.

 

Likewise, engineering studies would be needed to determine the marsh’s grade. Careful consideration should be given to this aspect, as topographic heterogeneity in general can create niche spaces that should enhance species diversity and be an important driver of the ecosystem’s functioning (Larkin et al. 2006). However, altering the landscape does not automatically yield benefits. In one case, smoothly mounded islands introduced at a tidal marsh in San Diego Bay became too saline for plants to take root, because scientists found the salts were being “wicked” to the soil surface (Larkin et al. 2006).

 

Abiotic Considerations

Though some recent restoration efforts have shown that spartina can grow in various soil conditions, it may be important nonetheless to import sediment that is known to have supported the plant, especially if the existing substrate at the Riverside Park site appears to be inhospitable to supporting the plant’s establishment. There may be two avenues to achieve this goal. One is to piggyback on the U.S. Army Corps of Engineers project in Jamaica Bay, where engineers are pumping more than 270,000 cubic yards of sand that was dredged from local navigational channels are being used as substrate for a massive spartina planting effort (U.S. Army Corps of Engineers New York District 2006). Perhaps there would be excess sediment from this project that could be used at Riverside Park. Another is to import sediment stored at the Corps’ Historic Area Remediation Site, an offshore site where surplus sediment dredged from the New York and New Jersey region is taken (Lewis 2006).

Spartina Planting

Introducing Spartina alterniflora to the constructed marsh is a central, and crucial, element of the project – and its success. The composition of the substrate is unknown, making it difficult to ascertain at this juncture whether sediment would need to be brought in which to plant the spartina. However, spartina has been known to grow in various types of substrate if the plants are in the appropriate tidal range and are protected (Lewis 2006). For example, spartina was successfully introduced in sandy soil in a salt marsh project on Poplar Island in the Chesapeake Bay (Lewis 2006).

 

It is estimated to take about 30,000 spartina plants to achieve a successful introduction, or roughly 1 plant per 1.5 square feet. The density assumes that one acre of the three-acre site would be terrestrial (the rest tidal water) where planting could occur. The density of the spartina planting likely would be higher, as not all the land at the site would be available, especially if walking paths or an exhibit center were built or upland areas are created, which would necessitate different species of plants, such as Spartina patens and Distichlis spicata. The estimate reflects the high end of a range from two recent salt marsh restoration efforts. In June 2004, the Save the Bay organization planted 15,000 Spartina alterniflora plants on a half-acre site at a constructed salt marsh site in Providence, R.I. (Lewis 2006). But it had to replant 4,000 spartina over the next two years to replenish population losses, possibly suggesting the initial estimate was low, though managers believe wave energy contributed extensively to the losses (Lewis 2006). Meanwhile, the U.S. Army Corps of Engineers planted an average of 13,000 Spartina alterniflora plants over 70 acres in June 2005 in a salt marsh restoration effort in Jamaica Bay, an estuary located in New York City (Lewis 2006).

 

The reason why a higher density is recommended for this proposal is because the Riverside Park marsh would be an isolated patch and thus likely would not be replenished by propagules from nearby marshes. So, the planting would need to be denser to mitigate for some losses and the lack of support from nearby plant communities.

 

Seeding the area was considered but is not recommended. First, several projects examined as references did not use seeds. Also, it would seem that the spartina planted in a novel environment, such as Riverside Park, would be more likely to survive installed as a plant than simply seeded. There are many sources for the plants, from nearby communities, regionally or even grown commercially. Nearby, donor sites include Jamaica Bay, Inwood Hill Park and the Hackensack Meadowlands. Regionally, there are scores of salt marshes from where plants could be culled. Commercial growers include Pinelands Nursery & Supply in New Jersey.

 

To keep costs down, the recommendation is to take seeds from nearby spartina communities and grow the plants at The Greenbelt Native Plant Center, a greenhouse and nursery complex owned and operated by the New York City Department of Parks and Recreation that grows native plants for city-sponsored restoration and management projects (New York City Department of Parks & Recreation 2006).

A parallel effort would be to recruit school groups to grow spartina from seed. Save the Bay successfully adopted this strategy for its Providence project (Lewis 2006). It’s an excellent idea and the perfect entrée for cementing school and community ties to the project.

 

The recommendation is to use coir mats during the spartina planting, to keep the sediment in place during planting and to help the spartina take root. The mats can be purchased commercially.

 

Genetic variation can be a crucial variable to a restoration project’s success, making the decision whether to draw plants from local, limited plant populations or from large, genetically diverse populations a difficult one. The recommendation here is to establish a “regional mixture,” capturing a wider array of genotypes that can succeed in a new location. There is a risk of outbreeding depression, but the thinking here is that different genotypes associated with each other would produce plant strains better adapted to the new environment and thus better able to survive in a long-term sense.

 

Attention should also be given to microbial organisms that could help the spartina to flourish, such as fungal mycorrhizae, and other fungal associations that studies have shown are essential to establishment and nutrient uptake by most higher plants (Lambers et al 1998; Chapin et al 2002; Fitter and Hay 2002).

 

Other Biota

A successful planting of the spartina is the project’s primary goal, in essence setting the table for the ecosystem to develop characteristics of a natural marsh. But there are other biota that will certainly assist in this transformation and should not be overlooked. Two primary species are the fiddler crab (Uca pugnax) and the ribbed mussel (Geukensia demissa). The fiddler crabs help aerate the soil, and their burrowing also creates space for the spartina to establish its roots deeper in the soil. The ribbed mussel can filter high volumes of water in the tidal marshes during each cycle, is an important prey species for birds and the blue crab and may produce nitrogen-rich feces that enhance grass growth. (Chesapeake Bay Program 2006; Biological Sciences, State University of New York at Stony Brook 2006).

 

Then it would be up to the Hudson to do its job, supplying the marsh with other invertebrates and fish, in short, creating the food web integral to the marsh’s biodiversity and ecosystem functioning. The final addition to this trophic-level puzzle would be birds flocking to the marsh to feast upon the supply of prey species. This bottom-up approach to restoring salt marshes appears to be the trend in restoration ecology, and it is the recommended approach with this project.

 

Monitoring and Management

The monitoring and management of the newly created marsh is essential to giving it the best chance of success. The process would encompass five areas: tidal circulation, exotic and invasive species, nitrogen and phosphorous soil concentrations, pollutants and human disturbance.

 

As referenced elsewhere in this paper, the Hudson’s strong tidal flows could overwhelm the constructed marsh. There are ways to prevent that from happening. They include angling the tidal channel so that it does not take the full force of river current and wave energy and reinforcing the banks along the channel with riprap; building a water control structure to diminish tidal flow into the marsh and regulate the volume of salt water entering the marsh; and creating additional channels in the marsh to ease the volume and strength of flows throughout the wetland. Each approach can be studied in the design phase to decide which may work best.

 

Exotic and invasive species will be a regular threat to the marsh’s health and could disrupt its evolution. Constant monitoring, likely for several years at minimum, will be needed.

 

The North River sewage plant releases nutrient-laden effluent into the Hudson, such as nitrogen and phosphorous. While nutrients are essential to biomass production, they can overwhelm a system and lead to eutrophication. However, it is possible that the nitrogen would be greatly diluted in the Hudson before it reached the site, though studies would be needed to test that hypothesis. Nixon and Buckley (2002) argue that nitrogen is beneficial to some ecosystems by stimulating secondary production. They note research in Scotland and in the Baltic Sea where benthic infauna and fish grew substantially from inorganic nitrogen and phosphorous additions.

 

Pollution and human disturbance also present real threats. One suggestion to minimize noise, air and runoff from vehicles on the Henry Hudson Parkway would be to create a buffer line between the marsh and highway that could include trees and shrubbery. The benefits of such a limited buffer should be balanced with its disadvantages, which include the potential that propagules from it would invade the marsh area, and the buffer area’s ability to withstand stressors to its own environment. Human disturbance from use of the bike path and walkways in the area are easily seen and managed.

 

Timeline

 

The projected timeline for this project is to complete the marsh by spring 2009, a fitting goal as it will be the 400^th anniversary of Henry Hudson’s voyage on this grand river that bears his name. The projected end date factors in one year to set up federal, state, local and private partnerships and to complete survey and design phases, approximately six months to gain permits and six months for constructing the marsh, planting the spartina and introducing any support species. The timeline’s phases are based on the experience of the U.S. Army Corps of Engineers, which has led several recent marsh recreation projects in the New York-New Jersey region and New England (Lewis 2006).

 

Budget and Labor

 

The proposed budget for the project is $1 million. The budget admittedly is a rough estimate and is meant to include a cushion for contingencies. Project organizers should highlight the high-profile nature of this project and be creative in seeking in-kind assistance – in particular for survey and design, sediment collection and transport to the site and spartina growing and planting. Some suggestions will follow. Also, there will be heavy reliance on volunteers, though recent history suggests that is a viable method to perform such projects.

 

The budget is based on the following calculations:

• Survey (In-kind)
• Design (In-kind)
• Construction (Funds needed)
• Spartina seeds (Volunteer collection from existing sites)
• Spartina growing (City-run greenhouse)
• Spartina planting (Volunteers)
• Monitoring/Maintenance (Volunteers under city park personnel)

 

There is ample recent history to suggest that in-kind assistance is available for several aspects of this proposal. One example is the marsh restoration effort at Walker Farm in Barrington, R.I., which received funding from the National Oceanic & Atmospheric Administration for site assessment, pre-restoration monitoring and design, while a private group, Ducks Unlimited, contributed design engineering, construction oversight and money for construction (Coastal Resources Management Council 2006).

 

Several federal agencies (a list will be provided in a later section) have given money, expertise and other assistance. In fact, the federal government has become increasingly involved in marsh recreation projects in the Northeast and can pay up to 75 percent of project costs (Lewis 2006).

 

Constructing the marsh and the water control structure, if needed, likely will involve funding. The Army Corps of Engineers has software that calculates costs for all phases of construction activity and should be used to determine this project’s construction budget (Lewis 2006). The federal government would generate the greatest percentage of the money, with the balance leveraged from state agencies, corporate and private sources. It is difficult to estimate total construction costs, as each marsh project is different. Construction at the one-acre Save the Bay project in Providence cost approximately $125,000 (excluding spartina plants purchase and planting). Extrapolating from that budget, the Riverside Park project would have construction costs of about $375,000, though it appears this project would be more intricate and thus incur higher costs.

 

Spartina seed collection would be carried out with the Army Corps of Engineers as the lead agency, with assistance from a group of volunteers. The Corps employed this strategy successfully at Jamaica Bay in fall 2005 (Lewis 2006).

 

The seeds can be grown in two places: One, identified earlier, is the city-run greenhouse on Staten Island. The other is the Natural Resources Conservation Service, a federal agency that has become increasingly involved in growing plant stock from seeds for salt marsh restoration projects. The NRCS grew spartina plants for the Corps’ Jamaica Bay project (Lewis 2006).

 

If the plants need to be purchased, the estimated cost would be about $20,000. The estimate is based on the cost per 2-inch plug from Pinelands Nursery.

 

The planting would be done with volunteers. It is difficult to gauge exactly how many volunteers would be needed but 300 is a good starting point, as it is double the number that participated in a Corps-led spartina planting at a one-acre site in Barrington, R.I. and twice the number who took part in the Save the Bay effort in Providence.

 

Again, volunteers would be heavily involved in the monitoring and management of the marsh, under the supervision of state or city parks personnel. There are creative frameworks in place to use as a guide. In Massachusetts, a volunteer-staffed program began in 1999 to monitor wetlands in the state. Citizens are trained at workshops that focus on six wetland parameters: birds, plants, water chemistry, land use, tidal influence and benthic macroinvertebrates (Merrimack Valley Planning Commission 2006). The Environmental Protection Agency has published handbooks on volunteer monitoring and management of wetlands (U.S. Environmental Protection Agency 2006).

 

Funding Sources

There are potential funding steams at several levels: federal, state, local, corporate and private. The funding can come in different forms, including direct financing, grants, in-kind gifts and assistance and volunteer labor.

 

Here is a list of potential funding sources for the Riverside Park project. All of them have funded recent salt marsh restoration projects either directly or indirectly. The list is meant to act as a starting point for identifying possible partners.

 

Federal: U.S. Army Corps of Engineers, U.S. Fish & Wildlife Service, Environmental Protection Agency, National Oceanic & Atmospheric Administration, Natural Resources Conservation Program (under the U.S. Department of Agriculture) and National Park Service.

 

State: New York State Department of Environmental Conservation and the Port Authority of New York and New Jersey.

 

Private: Corporations, especially those that have budgets for community betterment projects; individuals engaged in philanthropy.

 

Conclusion

 

Henry Hudson first laid eyes on the Hudson in 1609, and he exuberantly wrote about what he saw. In his journal, he described the river teeming with fish and other species -- life no doubt nurtured by the marshes that lined the shores of Manhattan and New Jersey. Today, the remarkable benefits of wetlands are known. They are valuable, even invaluable. It is time to bring them back.

 

Now, imagine a marsh in Manhattan. People strolling the bike path could one again gaze at one of nature’s most unique creations. They’d see the elegant, feathery tops of spartina swaying in the breeze, its stems sashaying to the tides. They’d see birds plucking along in the water, beaks tapping the surface in search of fish. Perhaps they’d catch fleeting glimpses of crabs, small fish and other marine animals meandering along the bottom, their forms glinting in the sunlit waters.

 

Now imagine a chain of salt marshes along Manhattan’s western shoreline. Shore stabilization would be magnified, as would be the filtering of pollutants, the creation of more habitat for birds and fish, and better protection for people from storms and floods. Besides those tangible benefits, a chain of marshes would bring back a distant echo of time when the Hudson River estuary was this city’s harvest and its soul.

 

Does it really make sense to create an urban marsh? Simenstad et al. (2005) touch upon some disadvantages, noting that constraints to size and design can hamper habitat functioning, while pollution and invasive species can threaten the restored site’s sustainability. All this is true. But, as the authors also point out, urban marshes can overcome the negatives if they expose the public to the value of a particular ecosystem and beautify the landscape. That is exactly the case here.

 

 

Literature Cited

 

City of New York Department of Parks & Recreation. 2001. Inwood Hill Park: Salt marshes in New York City parks. http://www.nycgovparks.org/sub_your_park/historical_signs/hs_historical_sign.php?id=12864

New York State Department of Environmental Conservation. 2005. Hudson River Estuary Action Agenda.

Craft, C., J. Reader, J.N. Sacco, and S.W. Broome. 1999. Twenty-five years of ecosystem development of constructed spartina alterniflora (loisel) marshes. Ecological Applications 9 (4):1405-1419.

Craft, C., P. Megonigal, S. Broome, J. Stevenson, R. Freese, J. Cornell, L. Zheng, and J. Sacco. 2003. Ecological Applications 13(5):1417-1432.

Moy, L.D., and L. Levin. 1991. Are spartina marshes a replaceable resource? A functional approach to evaluation of marsh creation efforts. Estuaries 14(1):1-16.

Craft, C., J. Reader, J.N. Sacco, and S.W. Broome. 1999. Twenty-five years of ecosystem development of constructed spartina alterniflora (loisel) marshes. Ecological Applications 9 (4):1405-1419.

Craft, C., P. Megonigal, S. Broome, J. Stevenson, R. Freese, J. Cornell, L. Zheng, and J. Sacco. 2003. Ecological Applications 13(5):1417-1432.

Posey, M.H., T.D Alphin, and C.M. Powell. 1997. Plant and infaunal communities associated with a created marsh. Estuaries 20 (1):42-47.

Muir, T. 1990. U.S. Fish and Wildlife Service. Personal communication.

Lewis, R.C. 2006. Personal communication with Wenley Ferguson, restoration coordinator, Save the Bay.

Larkin, D., G. Vivian-Smith, and J.B. Zedler. 2006. Topographic heterogeneity theory and ecological restoration. Foundations of Restoration Ecology. 7:142-164.

U.S. Army Corps of Engineers New York District. 2006. Stemming the tide of marsh loss in Jamaica Bay with $13M urban wetlands project. Press release.

Lewis, R.C. 2006. Personal communication with Peter Weppler, chief, environmental evaluation section,
U.S. Army Corps of Engineers, New York District.

Lewis, R.C. 2006. Personal communication with Tom Ardito, outreach and policy coordinator, Narragansett Bay Estuary Program.

Lewis, R.C. 2006. Personal communication with Wenley Ferguson, restoration coordinator, Save the Bay.

Lewis, R.C. 2006. Personal communication with Peter Weppler, chief, environmental evaluation section
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New York City Department of Parks & Recreation. 2006. Greenbelt Native Plant Center. http://www.nycgovparks.org/sub_opportunities/internships/greenbelt_native_plant_center.html.

Lewis, R.C. 2006. Personal communication with Wenley Ferguson, restoration coordinator, Save the Bay.

Lambers, H., H. Poorter, and M.M.I. Van Vuven. 1998. Inherent variation in plant growth. Leiden: Bachuys Publishers.

 

Chapin III, F.S., P.A. Matson, and H.A. Mooney. 2002. Principles of terrestrial ecosystem ecology. New York: Springer Verlag.

Fitter, A.H., and R.K.M. Hay. 2002. Environmental physiology of plants. Academic Press, London.

Chesapeake Bay Program. 2006. http://www.chesapeakebay.net/ribbedmussel.htm.

Biological Sciences, State University of New York at Stony Brook. 2006. http://life.bio.sunysb.edu/marinebio/spartina.html

Nixon, S.W., and B.A. Buckley. 2002. Estuaries 25(4B):782-796.

Lewis, R.C. 2006. Personal communication with Todd Randall, marine ecologist, US Army Corps of Engineers, New England District.

Coastal Resources Management Council. 2006. Walker Farm marsh restoration project.  http://www.crmc.ri.gov/projects/walkerfarm.html.

Lewis, R.C. 2006. Personal communication with Todd Randall, marine ecologist, US Army Corps of Engineers, New England District.

Lewis, R.C. 2006. Personal communication with Peter Weppler, chief, environmental evaluation section
,
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Merrimack Valley Planning Commission. 2006. http://mvpc.org/services_sec/mass_bays/8T&B_volunteers.htm.

U.S. Environmental Protection Agency. 2006. http://www.epa.gov/owow/wetlands/monitor/volmonitor.html.

Simenstad, C., C. Tanner, C. Crandell, J. White, and J. Cordell. 2005. Challenges of habitat restoration in a heavily urbanized estuary: Evaluating the investment. Journal of Coastal Research 40:6-23.