(The following is excerpted from the Executive Summary of "Tidal Brackish Marsh Mitigation in the New Jersey Meadowlands: Using Long-term Monitoring Data from Three Mitigated Urban Marshes to Develop Guidelines for Future Enhancement Efforts" by Jean Marie Hartman, Niki Learn, Mark Wong, and Jennifer Momsen, 2007. A full list of the Literature Cited in writing this document is also available.)

”Rutgers, The State University of New Jersey and the Hackensack Meadowlands Development Commission, now the New Jersey Meadowlands Commission (NJMC), began a program of biological monitoring of wetland mitigation projects in 1997. The mitigation sites had formerly been dominated by Phragmites australis (common reed), which excludes other vegetation, raises land elevation to the point of obstructing tidal flow, and is used by a relatively low diversity of wildlife. Enhancement activities involved removal of Phragmites, creation of open water areas, and restoration of tidal flow. Within a memorandum of understanding, Rutgers was put in charge of documenting the progressive restoration of wetland functions and values on the enhancement sites and with providing long-term data on the effects of the mitigation efforts on the Meadowlands environment as a whole. One part of the biological monitoring program focused on three wetland enhancement sites and regulatory permits. Simultaneously, the Rutgers team investigated methods of restoration, wetland functions, and wetland assessment methods...

”From the beginning, the NJMC and Rutgers recognized that the evolving science of restoration ecology could be applied and developed within this setting. Although each wetland enhancement project was designed with the state of knowledge available in 1997, a great deal has been learned in the past ten years.

”The primary effort of the Rutgers team has been focused on three mitigation sites owned and enhanced by the NJMC. These sites were monitored extensively, producing a valuable data set for determining the effectiveness of past enhancement efforts in tidal brackish marshes of the Meadowlands. Vegetation was the primary assemblage monitored... Data show mixed results in that some habitats at some marshes displayed adequate cover and developed zonation, while others did not due to failure of tall tidal marsh species to recruit to the sites... Creation of natural marsh structure and function thus depends to some degree on the species that dominate the vegetation, making planting of these species a primary concern during any enhancement effort. Invasive and weedy species will always be problematic in such an urban setting as the Meadowlands and will need to be monitored and managed over the long term.

Since goals of the design plans included increasing habitat for waterfowl and migrating shorebirds, avian species were also monitored, using periodic point-count surveys conducted year-round. This data was also collected prior to mitigation at two of the three sites, offering a valuable point of comparison for post-mitigation monitoring... Species diversity and avian abundance at the two sites monitored both before and after mitigation increased dramatically by the first survey data following completion of construction. Use of these two marshes by target waterfowl and mudflat-foraging shorebirds soared following enhancement. A total of 130 avian species were identified at all sites combined. The smallest site, whose setting is more urban and farther removed from non-Phragmites marsh, saw far fewer birds than did the larger sites and was less well used by many of the shorebirds and waterfowl that dominated the avian communities of the two larger sites. The site with substantial cover of high marsh grass and rush species hosted the highest species richness and mean abundance per survey. Waterfowl were also observed nesting in this tall tidal marsh vegetation. This site, with significant areas of open water, mudflat, and high marsh vegetation appeared to have a combination of habitats that was more attractive to most wetland bird species.

”Fish sampling was performed primarily by seining at the two larger sites, while traps and a gill net were used during less intensive sampling efforts at the smallest site. Fish populations appeared to respond to enhancements more slowly than did avian species and were more heavily impacted by a severe regional drought that spanned portions of 2001 and 2002. Overall, however, both species richness and abundance increased over time at the two larger sites and by the end of monitoring both resident and nonresident fish species were regularly captured in impoundments and channels at the sites with dominance by the marsh resident Fundulus heteroclitus (mummichog) decreasing over time even as abundance of this species increased... The presence of large numbers of young fish, particularly of F. heteroclitus, Menidia menidia (Atlantic silverside), and Menidia beryllina (inland silverside), indicates that the marshes are acting as spawning areas for several fish species.

”Benthic invertebrates were the third animal assemblage that was monitored for three or more years... Each marsh produced a somewhat distinct benthic invertebrate community with the smallest site having the least diverse community, a community heavily dominated by nematodes. Because of the large number of biotic and abiotic factors that affect the benthic invertebrate community on a variety of scales and because high resolution of many taxa is quite difficult and not universally performed, it is difficult to use these data to evaluate marsh condition and function. Combined with the greater time and expense of performing such monitoring, we conclude that plant, avian, and fish data are more useful in assessing marsh condition and evaluating mitigation success...

“A variety of wetland assessment methods were tested with monitoring, GIS, and map data. Due to their current popularity among regulators and watershed managers, a comparison of the results produced by rapid and semi-rapid assessment methods relative to those produced by the in-depth monitoring was performed. Our results indicate that rapid assessment and other assessment methods may not be suitable for use in the Meadowlands. Specifically, we found that these methods did not fully capture the condition or functions of the three mitigated wetlands, were unable to capture variation in vegetation and fauna communities at the marshes over time, and did not appropriately consider the surrounding urban landscape. If and when a rapid assessment is to be used to evaluate the tidal urban wetlands of the Meadowlands, the method must be able to examine biodiversity and presence of invasive and weedy species, and to evaluate whether or not normal marsh structure and function are developing. It must therefore look specifically for evidence of vegetation zonation and for presence of key plant species or growth forms. It also needs to consider hydrology and geomorphological processes to fully determine marsh functionality and evaluate the wetland’s ability to sustain itself over time. It may be some time before a scientifically sound rapid method can be developed and more in-depth monitoring is recommended at present. An analysis of the extensive monitoring data shows that mid-to-late summer vegetation monitoring of permanent plots and carefully constructed seasonal monitoring of avian and fish assemblages would provide robust data on systems structure and function.