Ecological Uplift in an Urban Setting

The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts.

Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift.

In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed.

The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.

2005 (Before Plantings)
2019
In 2004, Prologis hired Princeton Hydro to restore an 18-acre area adjacent to the Elizabeth Seaport Business Park, which a significantly disturbed and degraded mosaic of wetland and upland areas. This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.

The freshwater wetland aspect of the mitigation plan, which included inundated emergent, emergent, and forested habitat, was designed to be a combination of wetland creation (2.40 acres) and enhancement (8.79 acres), emphasizing the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife food value.

The upland forest aspect of the mitigation plan involved the enhancement of 5.40 acres and creation of 1.45 acres of upland forest to foster the development of a species rich and structurally complex upland forest. The upland areas targeted for enhancement/creation consisted of areas where woody vegetation was lacking or forested areas that were dominated by eastern cottonwood.

2008
2019
The 18-acre site in Elizabeth, NJ had huge potential but was significantly degraded and was being vastly underutilized. The mitigation plan emphasized the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife habitat value.

The project team worked to remove Phragmites australis from the site utilizing a combination of herbicide and mechanical removal techniques. Once the Phragmites australis was cleared, the team installed 27,000 two-inch native herbaceous plant plugs in the wetland portions of the mitigation site, and 2,705 native trees/shrubs throughout the site.

In order to ensure the continued success of the mitigation project, monitoring is regularly conducted at the site. A monitoring report conducted at the end of 2019 revealed a plethora of well-established habitat areas, a diverse community of plant and tree species, and a thriving, highly-functional landscape.

2004 (Before Plantings)
september 2019
In 2004, before the restoration work began, the site consisted of degraded Phragmites australis dominated wetlands and an urban woodland area dominated by Eastern cottonwood. The planting component of the mitigation project commenced in 2015, and the installation of all woody plant material began Fall 2015 and was completed in Fall 2016. The 2019 Monitoring Report revealed the plantings are well-established and the area is thriving.

Presently, the Elizabeth Seaport Business Park Mitigation Site boasts a variety of productive wildlife habitats that are rare in a highly urbanized setting and provides valuable ecosystem services, including sediment retention and roosting, foraging, and nesting opportunities for both resident and migratory bird species with over 150 bird species identified within the mitigation site.

2008
2019
The Elizabeth Seaport Business Park site was comprised of a monoculture of Phragmites australis, also known as Common Reed. The mitigation plan focused on enhancing the existing wetland by eradicating non-native-invasive plant species, like Phragmites, and establishing more diverse population of productive, native species with high ecological value.

This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.  If you’d like to learn more about this project from our Natural Resources Senior Project Manager Michael Rehman, check out the video of his presentation at the 2020 Delaware Wetlands Conference below.

We’re at the Delaware Wetlands Conference and our Senior Project Manager, Michael Rehman, is presenting on a successful urban wetland restoration in Elizabeth, NJ.

Posted by Princeton Hydro on Thursday, January 30, 2020

 

If you’re interested in learning more about our wetland restoration and mitigation services, go here!

Restoring the Northernmost Freshwater Tidal Marsh on the Delaware River

By Kelsey Mattison, Marketing Coordinator

Located in Hamilton Township, New Jersey, Mercer County’s John A. Roebling Memorial Park offers residents in the surrounding area a freshwater marsh with river fishing, kayaking, hiking, and wildlife-watching. The park contains the northernmost freshwater tidal marsh on the Delaware River, Abbott Marshland. Since the mid-1990s, many public and private partnerships have developed to help support the preservation of this important and significant marsh.

Tidal marshes, like the 3,000-acre Abbott Marshlands, contain valuable habitat for many rare species like River Otter, American eel, Bald Eagle, and many species of wading birds. Unfortunately, the Abbott Marshland has experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis, or, Common Reed.

Phragmites australis

Phragmites australis is a species of grass that has a non-native invasive form that creates extensive strands in shallow water or on damp ground. The reed tends to colonize disturbed wetlands and then spreads very rapidly, outcompeting desirable native plant species. Once it is established, it forms a monoculture with a dense mat and does not allow any opportunity for native plants to compete. This impairs the natural functioning of the marsh ecosystem by altering its elevations and tidal reach which impacts plant and animal communities. Over the last century, there has been a dramatic increase in the spread of Phragmites australis, partly due to development impacts that resulted in disturbances to wetlands.

For the Mercer County, Princeton Hydro put together a plan to reduce and control the Phragmites australis, in order to increase biodiversity, to improve recreational opportunities, and to improve visitor experience at the park. This stewardship project will replace the Phragmites australis with native species with a goal to reduce its ability to recolonize the marsh. In September, our Vice President Mark Gallagher and Senior Project Manager Kelly Klein presented our plan to the public at the Tulpehaking Nature Center.

Vice President Mark Gallagher presenting on the project at the Tulpehaking Nature Center.

Princeton Hydro conducted a Floristic Quality Assessment to identify invasive areas and performed hydrologic monitoring to understand tidal stage elevations. Phase 1 of the restoration process occurred this fall and included herbicide applications to eradicate the Phragmites australis. The herbicide used, Imazapyr, is USEPA and NJDEP approved and our field operation crew applied it using our amphibious vehicle called a Marsh Master. For harder to reach areas, we used our airboat.

According to a USDA report, Imazapyr has been extensively studied, and when properly applied, it has no impact to water quality, aquatic animal life, birds, or mammals, including humans. It works by preventing plants from producing a necessary enzyme called acetolactate synthase.

The goal of this wetland restoration project is to enhance plant diversity, wildlife habitat, and water quality in John A. Roebling Memorial Park. In late spring of 2019, we will revisit the site to continue spraying the Phragmites australis. By Spring of 2020, we expect to see native species dominating the landscape from the newly exposed native seed bank with minimal Phragmites australis. Stay tuned for more photos from the field when our Field Crew returns to the site for Phase II in early Spring!   

View of John A. Roebling Memorial Park from the access road.

For more information about Princeton Hydro’s invasive species removal and wetland restoration services, visit: bit.ly/InvasivesRemoval 

Kelsey Mattison is a recent graduate of St. Lawrence University with a degree in English and environmental studies and a passion for environmental communication. Through her extracurricular work with various nonprofit organizations, Kelsey has developed expertise in content writing, storytelling, verbal communication, social media management, and interdisciplinary thinking. Her responsibilities at Princeton Hydro include social media management, proposal coordination, editorial overview, and other marketing tasks. As a member of the Princeton Hydro team, she aims to further its mission by taking creative approaches to communicating about our shared home: Planet Earth.