The Beneficial Use of Dredged Material to Enhance Salt Marshes
August 2021

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

Monitoring Plan

The New Jersey Reference Wetland Tool by Riparia at Penn State and NJDEP
July 2021

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
December 2020

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.

Full Report

Diatom Flora of the New Jersey Coastal Wetlands
August 2019

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

Full Report

New Jersey Wetland Program Plan 2019-2022
March 2019

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

Full Report

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
Final Report

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.

Report

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.

Report
Appendix A-Database
Appendix B-D

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.

Report
Appendix

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.

Full Report
Executive Summary and Introduction
Design and Methods
Quality Assurance Program
Results and Discussion
Data Analysis
Conclusions, Recommendations & References
Appendices