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Poplar Island Overview

Poplar Island, recently on the verge of disappearing, is today a national model for habitat restoration and the beneficial use of dredged material. Just off the Chesapeake Bay coastline, about 34 miles south of Baltimore in Talbot County, Md., Poplar Island is being returned to its former size and important ecological function while helping to ensure the economic vitality of the region.

Working in partnership with the Maryland Department of Transportation Maryland Port Administration and other Federal and State agencies, the Corps of Engineers are currently restoring Poplar Island by using dredged material from the Baltimore Harbor and Channels Federal navigation projects. Approximately 68 million cubic yards of dredged material will be placed to develop 776 acres of wetlands, 829 acres of uplands and 110 acres of open water embayment.

Project Information

In 1846, Poplar Island boasted more than 1,000 acres. During the early 1900’s the island supported a thriving community of about 100 inhabitants, several farms, a school, a church, a post office and a saw mill. By the 1920’s, residents began leaving the island as more and more of its landmass fell victim to erosion. By the early 1990’s, all that remained were several small clusters of islets rising just above the surface of the water. Reduced to about four acres, Poplar Island’s disappearance seemed imminent.

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Beneficial Use - A "Win-Win" Concept

Rather than let the island disappear, an interagency team from the U.S. Army Corps of Engineers, Maryland Port Administration, and many other federal and state environmental agencies decided in 1994 that the island was worth saving.

The project’s partners began soliciting input from local communities, businesses and environmental groups about ways to accomplish this effort. They decided to explore the possibility of using dredged material from the navigational channels leading to the Port of Baltimore to rebuild the island to approximately its 1847 footprint.

The Port of Baltimore as well as most other U.S. harbor and channel systems, must be dredged in order to stay open and remain competitive. The many rivers that flow into the Chesapeake Bay bring a constant supply of fine silt, which settles into the shipping channels.

To keep the waterways safe and the port economically viable, routine maintenance dredging and placement at the island has to be done. This has led to the increasing challenge of finding suitable placement area for the material.

Following the necessary environmental studies, government, business, conservation and civic groups and other stakeholders decided that rebuilding Poplar Island was not only viable but could create more than 1,000 acres of diverse habitat. In rebuilding the island, dredged material would be placed and shaped to create wetlands and uplands habitats that would serve as home to many of the Bay’s treasured wildfowl. Their decision is seen by most as a "win-win" solution.

Rebuilding an Island and Expanding

The remnants of the original Poplar Island consisted of clusters of low, marshy knolls and tidal mudflats. Using these remnants, engineers first constructed more than six miles of containment dikes using sand, rock and stone around the last remnants of Poplar Island. Within the dikes, clean dredged material is pumped in and allowed to properly drain to maximize the island’s placement capacity. Extensive engineering work goes into the habitat development and has significantly contributed to Chesapeake Bay restoration goals.

As the wetlands mature, they serve as a natural filter to improve water quality and a valuable habitat for birds, crabs, small fish and shellfish. Shortly after the first dredged material was placed on the island in 2001, ospreys, egrets, terns, herons, eagles, terrapins and other wildlife began to call the restored island home.

In 2007 Congress authorized Poplar Island to expand from its historic footprint of 1,140 acres to 1,715 aces in order to restore more island habitat and store more dredged material. Construction for the expansion began in 2016 and includes a lateral expansion of 575 acres to the north as well as the raising of the existing uplands to 25 feet. the expansion includes a 110-acre open water embayment with a depth of up to 12 feet.

The final project will contain about 68 million cubic yards of dredged material and will consist of approximately 776 acres of tidal wetlands, including low marsh and high marsh habitat, bird nesting island, and ponds; as well as approximately 829 acres of upland habitat.

Economic and Environmental Benefits

Economic

The project serves as an environmentally beneficial solution to the dredged material placement problems facing the Port of Baltimore. The Port estimates that over the next 20 years, maintenance dredging, coupled with needed improvements to the Chesapeake Bay's shipping channels, could generate as much as 100 million cubic yards of dredged material. A disruption in the constant maintenance that is required to keep the Port of Baltimore operational would result in significant adverse effects to both the local and national economy. The Port handles approximately 30.8 million tons of commerce per year, contributes $1.9 billion in business to the state's economy and generates 50,200 jobs, 16,500 of which are directly related to Port activities. Revenue impact from the Port represents one-tenth of Maryland's gross product. The Port of Baltimore is ranked number one in the U.S. for automobile exports.

Environmental

Poplar Island has been identified by the U.S. Fish and Wildlife Service, the Maryland Department of Natural Resources, and many other resource management agencies as a valuable nesting and nursery area for many species of wildlife, including eagles, osprey, heron, and egret. Island habitat for many wildlife species native to the Chesapeake Bay is sparse and degrading, but creating the combination of upland, wetland, near-shore, and shoal habitats during restoration of the island will offer a critical diversity of habitat resources.

Project Costs

On September 4, 1996, the Record of Decision was signed and the project was subsequently approved for construction under Section 537 of Water Resources Development Act 1996. The expansion of Poplar Island was authorized under Section 3087 of the Water Resources Development Act of 2007. A Project Cooperation Agreement was executed with the State of Maryland in 1997, with the project to be cost-shared 75 percent Federal and 25 percent non-Federal for the existing project. For the expansion part of this project, the cost-shared is 75 percent Federal and 25 percent non-Federal. It is projected that the project will be able to accept dredged material until 2029 and all the habitat created by 2041 at an estimated cost of $1.4 billion.

The Island's Future

As Poplar Island continues its resurgence, engineers, scientists and others from around the country will closely monitor its success. When the rebuilding of the island is complete, the State of Maryland will manage its long-term stewardship. Many believe the restoration of this island and its habitat will serve as an important link in the ecological chain that anchors the Chesapeake’s incomparably rich natural bounty.

Records and Documents

Monitoring

Monitoring of the environment in and around Poplar Island is an integral component of the project. Detailed and regularly scheduled monitoring is essential to ensure success of the project, to identify changes in the environment surrounding the island, and to determine if ongoing operations need to be adjusted. Monitoring also document improvements as the project progresses, such as increases in vegetation cover and wildlife usage.

Several different types of environmental assessment and monitoring studies have been conducted and/or are ongoing at Poplar Island. These include baseline studies during pre-construction and pre-placement which will be compared to future data to assist with identification of changes to the environment. Additionally, operations monitoring encompasses all the monitoring that occurs during dredged material placement and dewatering. And as new habitats, such as uplands and wetlands, are created, the plants and animals within the habitats are monitored to determine how well the habitats are functioning.

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Terrapin Monitoring Reports

Wildlife Resources

The Chesapeake Bay is the largest estuary in the United States, and is a complex ecosystem that encompasses a wide range of habitats that support more than 3,600 species of plants, fish, and animals. The Bay is also a very productive habitat, producing over 500 million pounds of harvested seafood each year. Some Bay habitats, particularly shorelines and submerged aquatic vegetation, are in critical need of restoration. Five different habitat types are being created at Poplar Island. Not only will these habitats support a diverse assemblage of plants and animals, but some of the habitat types to be created include those that are most sorely needed in the Bay.

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Restoration Goals

Create bare/sparsely vegetated islands to provide nesting habitat for birds
Create/enhance vegetated islands to provide nesting habitat for birds
Create/enhance tidal wetlands to provide fish and wildlife habitat
Restore quiescent water habitat in Poplar Harbor to promote submerged aquatic vegetation recovery
Create remote and diverse island habitat

Upland Habitat

Upland habitat is land that is rarely or never inundated by water. Upland habitat supports the growth of grasses, shrubs, and trees, and provides habitat for birds, mammals, reptiles, and amphibians. As the upland habitat planted on Poplar Island matures into forested areas, the trees will stabilize soils, provide food/nesting/shelter habitat, and clean the air by absorbing or trapping particulates and nitrogen. Forests covered 95% of the Bay's watershed prior to European settlement in the 17th century. Today, less than 60% of the forested area remains. Trees in the watershed are dominated by a mixture of southern pines and northern hardwoods, so this type of mixture is being planted at Poplar Island.

Salt Marshes (High Marsh and Low Marsh)

Salt Marshes are wetlands that are comprised of salt tolerant grasses and experience periodic flooding by tides. Low marshes are regularly flooded by tidal waters, whereas high marshes are irregularly flooded, and when flooding does occur it is due to strong winds or exceptionally high tides. Salt marshes provide critical habitat for juvenile fish and shellfish, waterfowl, shorebirds, wading birds, mammals, and a variety of invertebrates, including shrimp, fiddler crabs, marsh crabs, and marsh periwinkle. Estuarine marshes, including salt marshes, serve as nurseries and spawning grounds for many commercially important fish and shellfish species, such as striped bass, menhaden, summer flounder, bluefish, oysters and blue crabs.

Tidal Flats

Tidal flats are unvegetated wet areas of mud or sand that do not contain rooted plants, and are subject to tidal flooding. Tidal flats occur along the shoreline of the Bay, and typically border marsh areas. Tidal flats are comprised of a mixture of silt, clay, and organic material. Although not vegetated, tidal flats provide habitat for a variety of invertebrates, which serve as a primary food source for many Bay shorebirds, including oystercatchers, terns, gulls, and plovers. Inhabitants of tidal flats that live in mud/sand include tiny roundworms that live in the top two inches of silt, various species of bristle worms, and burrowing clams that extend their siphons to the surface. Other invertebrates live on the surface of the tidal flat, such as fiddler crabs and mud snails.

Nesting Islands

Poplar Island also includes unvegetated shell beaches and nesting islands. This type of habitat provides nesting areas for shorebirds such as the federally-endangered Least Tern.

Rocky Shorelines

Large rocks have been used to armor the dike surrounding Poplar Island. Not only do these rocks protect Poplar Island from erosion, but the areas of exposed rock that are fully submerged or tidally submerged will be colonized and used as habitat by invertebrates that attach themselves to the rocks, such as bay barnacles, sea squirts, and mussels. Eight submerged rock reefs have also been constructed at the northern end of the island to provide fisheries habitat.

Shallow Water Habitat

Shallow water habitat is aquatic habitat less than 6 feet deep. The shallow depth of the water permits light to penetrate throughout the water, which enables plants to survive in both surface waters and at depth. Shallow water habitat in the Bay contains three important plant communities: phytoplankton, benthic algae, and submerged aquatic vegetation. In addition to plant communities, shallow water habitat contains swimming organisms, called "nekton" (e.g., finfish), and "benthic" (bottom-dwelling) organisms (e.g., oysters, clams, worms).

Mammals

To date, five mammals have been observed on Poplar Island – beaver, white-tailed deer, river otter, raccoon, and house mouse. Note that these mammals were not introduced species as part of the restoration efforts, but already occurred on the nearby islands.

Reptiles and Amphibians

Three species of reptiles and amphibians have been observed on Poplar Island including northern water snake, diamondback terrapin, and Fowler's toad. The early success of the terrapins on Poplar Island has been very promising since shoreline development in the Bay has threatened terrapins' nesting habitat.

Management of Wildlife Resources on Poplar Island

As the Poplar Island restoration process begins, the control of invasive and non-native species to the Island is essential to the success of the project. Species that have already required some control measures include the common reed and mute swan.