Cuyahoga County hired juwi GmbH to perform a feasibility study for LEEDCo’s offshore Pilot Project. The complete study is at
juwi in turn hired Curry & Kerlinger to conduct the portion of the study assessing avian risk. Their report is at
Curry & Kerlinger has been assessing wind power’s effects on birds for fifteen years, conducting studies in over 20 states, as well as Mexico, Puerto Rico and Spain.
Because at present the U S has no offshore wind turbines, information about their impact on birds is based on Curry & Kerlinger’s risk assessments from Europe, where the effects of offshore turbines on birds have been well studied. Many of the species that occur on Lake Erie also occur in European waters or are closely related.
Before turning the project over for avian assessment, LEEDCo chose the potential site for its turbines in accordance with the Ohio Dept of Natural Resources’ Turbine Placement Favorability Map. You can find the map at
LEEDCo also considered Audubon Ohio’s designation of the Cleveland Lakefront as an Important Birding Area. The area extends about one mile into the lake and doesn’t include the area under consideration for the Pilot Project.
juwi’s marine ecology-impact assessment: “The largest impacts to marine ecology will be short-term and limited to the construction phase of the Project. Short-term impacts would include physical disturbance of the lake bottom by removing the substrate, loss of benthic fauna and displacement of fish.
“Long-term, it is possible that the foundation structures will actually attract fish and otherwise provide marine habitat, similar to existing artificial reefs near the Project area.”
Curry & Kerlinger’s avian-impact assessment: Few birds will be in the waters of the Project Area during most of the year. When the area’s ice-bound, birds will be largely absent. In summer, Ring-billed and Herring Gulls and Double–crested Cormorants will be the most frequent visitors, though not in the numbers seen closer to shore. Large numbers of migrating Red-breasted Mergansers and Bonaparte’s Gull stage upon the lake in fall.
Curry & Kerlinger examined information from radar and other studies from sites in the central and eastern US concerning night-migrating birds. They found that songbirds, waterfowl and shorebirds fly mostly at heights above wind turbines. The same pattern exists above the Pilot Project area, as shown by an analysis of five years of archived weather-surveillance radar (NEXRAD). Nearly all hawks, day-migrating birds, migrate around the Great Lakes rather than crossing them.
Based on European studies, habitat (foraging) loss will be minimal. Small numbers of Common Loons may experience some displacement, but displacement isn’t likely with Red-breasted Mergansers, Double-crested Cormorants, Bonaparte’s Gull, Ring-billed Gull, and the Ohio endangered Common Tern.
However, the numbers of Herring and the Black-backed Gulls may increase offshore (Curses!) because of the attraction of human activity and of their viewing the Pilot Program installation as ideal perching platforms.
The Cleveland wind farm isn’t likely to pose a significant barrier to migrating species, nor will it significantly increase migration distance. According to European studies, most waterfowl and seabirds make short detours around offshore wind farms or fly through them below the rotor-swept area. Other studies show that some ducks can see the wind farms at night from about 500 meters and fly around them.
Measuring collision mortality is difficult on sea and on the Great Lakes. European studies indicate that the detours and avoidance by most waterfowl and seabirds decrease the number of potential collisions. As previously noted, a small percentage of night-migrating songbirds migrate below 500 feet, the maximum total height of Pilot Project turbines (including blade length)
Collision mortality for offshore night migrants, on a per turbine per year basis, should be similar to those reported for onshore migrants in studies of many Eastern and Midwestern U S wind farms. The Project-associated fatalities, when distributed among many species, will not affect songbird populations.
The assessment ends with this recommendation: “Post-construction studies of this pilot project will provide information needed to determine risk at future offshore wind development on Lake Erie, thereby ensuring that the wind resource is harnessed responsibly and with minimal environmental impacts.”
Accordingly, LEEDCo has committed to continuing, extensive bird/bat studies once the wind farm is active so that should issues arise, they can be addressed and serve as a source of learning
You’ll find more information about LEEDCo’s efforts to protect the ecosystem at http://www.leedco.org/faqs/ecosystem .