Wetland Restoration at John Heinz National Wildlife Refuge at Tinicum

Case Name:

M/T Athos I Crude Oil Spill

Country:

United States of America

Restoration Types:

Habitat Creation; Habitat Enhancement

State:

Pennsylvania

Affected DOI Resources:

Migratory Birds

City:

Philadelphia

Phase:

Implementation

Project Description

The John Heinz National Wildlife Refuge at Tinicum was established in 1972 to preserve Tinicum Marsh. Located near the mouth of Darby Creek, Tinicum Marsh once comprised over 5,000 acres of freshwater tidal wetlands before human activities reduced its acreage. The marsh was used as a disposal site for dredge materials from the Delaware River until the mid-1960s. During the 1960s, two landfills were established in the marsh and extensive dredging and filling occurred during the construction of Interstate 95. Due to the changes in hydrology, common reeds (Phragmites) have invaded large portions of the marsh. Approximately 200 acres of Tinicum Marsh remain today. To compensate for the injuries to intertidal habitats and tributary wetlands caused by the M/T Athos I oil spill, a wetland restoration project was proposed at the refuge. This project will include excavating seven acres of channels and pools to restore tidal flow to a 56-acre area of degraded marsh, and placing the excavated material adjacent to the pools to create scrub/shrub wetlands. The increased tidal exchange will allow the seeds from wild rice and other native plants to be transported into the interior of the wetland area. It may also lead to a decrease in Phragmites though periodic treatments will be required to control the species. The channels will provide habitat for diadromous species migrating through Darby Creek, including American eel, American shad, river herring, and striped bass. The scrub/shrub wetlands will create nesting sites for waterfowl and turtles, and roosting sites for wading birds. A detailed alternatives analysis will be conducted to determine the most cost-effective design to increase tidal exchange to the site including various channel alignments, breaching of the dike, and alternative disposal options. The project is expected to be completed in 2025.