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The Beneficial Use of Dredged Material to Enhance Salt Marshes
Salt marshes are one of New Jersey’s most important natural assets. They clean water, provide food and habitat for commercially and recreationally important fishes, buffer coastal communities from storms and are an integral part of the coastal viewshed - displaying giant expanses of green grasses and majestic birds. With increasing rates of sea level rise there is growing concern that these critical habitats are being lost and that the rate of loss will increase as rates of sea level rise continue to rise. After Super Storm Sandy (2012) there was an amplified understanding of how important salt marshes are, and as a result greater effort is being directed to enhancing their resiliency. While some salt marshes are drowning from lack of sediment or shrinking in area due to erosion, New Jersey navigation channels are clogged with sediment and traditional methods of disposing of dredged sediments are no longer viable. Thus, there is great interest in leveraging existing dredging projects to enhance or restore the resiliency of salt marshes that benefit coastal communities. This practice is referred to as the “beneficial use of dredged material”. Restoration practitioners are hopeful that it will decrease the cost of salt marsh restoration and lead to an increase in the number and size of projects. In 2013, the New Jersey Department of Environmental Protection, the New Jersey Department of Transportation, the U.S. Army Corps of Engineers, Green Trust Alliance, The Nature Conservancy and others initiated three pilot projects to test the theory that the application of dredged sediment on degraded or vulnerable salt marshes would improve ecological function and help them to persist into the future.
Project Summary and Lessons Learned
The New Jersey Reference Wetland Tool by Riparia at Penn State and NJDEP
A new Reference Wetland Tool was developed by Riparia at Penn State and NJDEP for New Jersey's tidal wetlands. Data from extensive wetland monitoring and assessment conducted within New Jersey, including the National Wetland Condition Assessment (NWCA); Mid-Atlantic Coastal Wetland Assessment (MACWA); Ecological Integrity Assessment (EIA); and other research are summarized in the tool, displaying the range in condition for tidally influenced wetlands (freshwater, brackish, saline) across the state. The tool is now live and displays information about wetlands of varying conditions, including those that are considered to be reference standard – sites that are the least disturbed and in best condition – for setting appropriate goals for wetland restoration projects.
NJ Reference Wetland Tool
Developing a Watershed-Scale Baseline for Tidal Wetlands
Tidal wetlands are critical habitat for the maintenance of secondary production of nekton. This study in the Wading River Estuary addresses two key factors: the specific structural and functional traits of coastal wetlands that make them conducive to supporting the secondary production of nekton and how individual components of the marsh are inter-connected to form a functional whole. We present an underlying framework for restoration success criteria that optimize secondary production and connectivity to adjacent habitats including the open waters of the estuary.
Diatom Flora of the New Jersey Coastal Wetlands
In 2012-2017 the New Jersey Department of Environmental Protection sponsored several research projects aimed at evaluating the potential use of diatoms for monitoring present and inferring past environmental conditions in New Jersey coastal wetlands. The goal of this report is to document the most common diatom taxa from studied wetlands, with high-resolution light and electron microscopy images. The images of 499 taxa found in the sub-, inter- and supratidal habitats and in sediment core samples are presented. Genera with the most species are Navicula (148), Fallacia (34), Nitzschia (21), and Parlibellus (16). Some taxa could not be identified to species level and are listed under provisional names. Voucher slides are deposited in the Diatom Herbarium of the Academy of Natural Sciences of Drexel University.
For further information, please contact Mihaela Enache
New Jersey Wetland Program Plan 2019-2022
New Jersey has taken a multi-faceted, comprehensive, approach to managing and protecting freshwater and coastal wetlands. This four-year Wetland Program Plan is an update of the first Wetland Program Plan the Department of Environmental Protection (NJDEP) developed in 2013. It provides a framework for the State of New Jersey to strengthen the core elements of its wetland program and to continue to reach the goals listed herein. The steps outlined will serve to direct current and future wetland protection and management efforts along a coordinated path to the benefit of New Jersey’s wetland resources and the quality of life for future generations.
For further information, please contact Metthea Yepsen
New Jersey (USA) Wetlands Past, Present and Future: Using Sediment Archives to Inform and Guide Wetland Protection, Restoration and Resilience- January 2018
This study was funded by the US EPA. This project was undertaken, in part, to fill the knowledge gap on reference wetland conditions in New Jersey. In this project, information obtained from sediment cores from four New Jersey coastal areas was used to track the impact of human activities since European settlement and provide quantitative information on reference conditions of NJ coastal wetlands. Nutrient concentrations, concentrations of organic (PAHs), and inorganic trace metals in core sediments were evaluated. This information is essential to provide restoration targets that are historically meaningful, achievable, and can be employed to protect and sustain NJ wetlands.
Nutrient and Ecological Histories in Barnegat Bay, New Jersey- June 2011
The primary objective of this project
was to collect sediment cores from
tidal regions of Barnegat Bay and
determine the chronology of nutrient
changes (i.e., nitrogen and phosphorus)
and associated ecosystem level responses.
Sediment nitrogen concentrations
increased towards the surface in
three of the 4 cores collected indicating
an increase in nutrient loading
from portions of the watershed.
Sediment nitrogen accumulation rates
increased twofold at the up-bay
site starting in the mid-1950s.
Algal diatoms indicate major shifts
toward more eutrophic conditions
starting in the 1940-1950s consistent
with an increase in sediment nutrients
and appear to indicate impacts from
increasing population and land use
in the northern part of Barnegat
Bay, an area with urban and suburban
land use. The southern site is situated
in a rural or semi-rural area and
was the least impacted. Wetlands
in Barnegat Bay can sequester approximately
79 % of the nitrogen and 54 % of
the phosphorus estimated to be entering
the Bay from upland sources. This
illustrates the important ecosystem
services that marshes can perform
and how important it is to maintain
and enhance marshes within Barnegat
Bay. Sedimentation rates on salt
marshes are at, or just below, the
rate of relative sea level rise
in Barnegat Bay. These relatively
low rates of accretion render the
marsh vulnerable to inundation should
the rate of sea level rise accelerate
in the future. Overall, the irreversible
shifts recorded by diatom species
suggest that, despite the fact that
the Barnegat Bay wetlands are protected
by both federal and state laws,
these sites remain impacted by anthropogenic
disturbances and did not return
to their natural, reference conditions.
On the contrary, the most recent changes suggest an increase in habitat
deterioration and pollution. Thus,
the changes recorded in diatom species
convey a strong message to identify
and limit all sources of nutrients
that contribute to the degradation
of the estuary and its watershed.
Research Project Summary
Wetlands Biological Indicators for New Jersey Case Study: Forested Riparian Wetlands in the Highlands of New Jersey - May 2006
The goals of this research were to build upon various wetland assessment projects conducted by New Jersey and to aid in development of a rapid wetland assessment tool that could work toward fulfilling the EPA mandate. A specific goal of this project was to identify biological indicators that reflect the ecological health and condition of riverine wetlands in the Highlands physiographic region. Longer-term goals are to better understand a) wetland condition and its relationship to water quality and b) to understand how broadly biological indicators can be applied to wetlands that vary in location, type and extent.
Development of Wetland Quality and Function Assessment Tools and Demonstration - June 2004
The specific goal of this study was to enhance the state's ability to identify indicators for wetland value and function. To this end, the study focused on a suite of rapid assessment tools designed to evaluate wetland quality and function that could be readily implemented in the field.
Testing a Wetlands Mitigation Rapid Assessment Tool at Mitigation and Reference Wetlands within a New Jersey Watershed – June 2004
This project and the companion study above, Development of Wetland Quality and Function Assessment Tools and Demonstration, address approaches to assessing wetland function. The specific purpose of this study was to assist NJDEP in evaluation of the wetland qualitative assessment method that was developed to determine the probability that mitigated wetlands will perform wetland functions.
Creating Indicators of Wetland Status (Quantity and Quality): Freshwater Wetland Mitigation in New Jersey - March 2002
The primary objectives of this study were to assess New Jersey’s progress toward wetlands mitigation goals and develop indicators of progress toward these goals. The research was conducted by Amy S. Greene Environmental Consultants, Inc. (ASGECI), and co-managed by scientists from both the New Jersey Department of Environmental Protection’s (NJDEP) Division of Science, Research and Technology (DSRT) and NJDEP’s wetlands regulatory program (Land Use Regulation Program or LURP). This study was supported by NJDEP’s Water Assessment and Environmental Indicators Research Programs. Relevant NJDEP managers were kept apprised of interim results and a peer review committee of leading state and national wetland scientists provided guidance throughout the duration of the study. For additional information about this report, please see the Dear Reader Section.
Summary and Introduction
Recommendations & References