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Ashtabula Harbor Breakwater Tern Nesting Habitat
Ashtabula, Ohio, United States
This demonstration project utilized design features built into Ashtabula Harbor Breakwater—a rubble mound structure used to protect the Ashtabula Harbor—to create nesting habitat for a state-listed endangered bird species, the common tern. The design features were initially incorporated during the first phase of the project, which was implemented in 2013. Toe blocks were cast with deep recesses in the top; the recesses, when filled with gravel, created an area that the tern would use for nesting. In 2014, a second phase of construction was completed that doubled the size of the nesting area. The project broadened the benefits provided by the breakwater and demonstrated that options can be economically employed during maintenance activities that increase infrastructure benefits consistent with U.S. Army Corps of Engineers (USACE) Engineering With Nature (EWN) principles. The U.S. Environmental Protection Agency’s Great Lakes Restoration Initiative (GLRI) and the USACE Dredging Operations and Environmental Research (DOER) program sponsored the development of the nesting habitat site, which was constructed by The Nature Conservancy (TNC) in coordination with USACE Buffalo District (LRB).
Article cover: The habitat was constructed on top of the existing breakwater to reduce potential impacts to the habitat by storm-induced waves. (Photo by Mike Guilfoyle, USACE)
Producing Efficiencies
The repair material consisted of pre-cast concrete blocks. Large blocks were used to form the base, or toe, of the structure, and smaller angled blocks were used to create the side slope with cap blocks at the crest. The design used modified toe blocks that were cast with a deep recess in the top that could be filled with gravel suitable for a nesting habitat. Several drain holes were included so that water would not accumulate in the recesses. The recess was also set in from the edges of the blocks so that the lip would unlikely be broken as a result of harsh environmental elements. In each corner of the recesses, PVC pipe was cast into the blocks to create sleeves that could accommodate posts that were part of the avian competitor/predator exclusion measures; these measures were also part of the habitat design efficiencies.
Using Natural Processes
During the development phase of this demonstration project, TNC was consulted and recommended reestablishing a breeding colony at this site. By demonstrating the value of repaired breakwaters for common tern nesting habitat, it is expected that similar harbor restoration efforts in the future may provide significant nesting habitat. This would lead to the eventual recovery of common tern populations in the Great Lakes Region.
Broadening Benefits
The common tern is native to the Great Lakes, but it has become locally extinct in many regions, including Ashtabula, as a result of habitat loss and competition by more aggressive gull species. These impacts have directly contributed to the species being listed as an Ohio endangered species. This project specified design changes as part of repairing a breakwater while producing greater environmental and social benefits by providing nesting habitat for the state-listed (Ohio) endangered common tern. Significant economic benefits were realized by leveraging a USACE project to add habitat.
Promoting Collaboration
Human-made nesting habitat for the common tern and other tern species has been successfully executed within the Great Lakes and other regions. TNC, with expert consultation from the Ohio Department of Natural Resources and the New York Department of Natural Resources, implemented this project in coordination with LRB and constructed the nesting habitat area. The U.S. Environmental Protection Agency’s GLRI and the USACE DOER program sponsored the development of the nesting habitat site.
