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Counting birds before a wind farm hatches 

DELAWARE CAPE GAZETTE (April 8 2008)

by Henry Evans, Jr., Cape Gazette Staff Writer

A specialized vessel supporting a research team that is counting migratory birds for Bluewater Wind is in Lewes preparing for the mission.

Bluewater, an offshore wind energy developer, is conducting the avian study over a two-to three-month period. Every week or so the ship’s crew and avian researchers will go ashore, rotating duty with another team. 

The R/V Russell W. Peterson, equipped with three 70-foot legs used to lift it above water, arrived at Lewes’ City Dock on Monday, March 31.

“You won’t see many boats like it in this area, but they’re common around Louisiana and Texas,” said Capt. Collin Clement, skipper.

Aqua Survey Inc., based in Flemington, N.J., owns the vessel.

The boat was christened after former Delaware Gov. Russell W. Peterson in Wilmington on March 29.

Peterson served as governor from 1969 to 1973, and is a proponent of Bluewater’s plans to build a 150-turbine wind farm 12 to 14 miles off Rehoboth Beach.

Peterson, 91, has a history of environmental stewardship, and is near legendary for his role in the passage of 1971’s Coastal Zone Act, which made much of the state’s coastline off-limits to heavy industry and development.

The R/V Peterson is serving as a base for Geo-Marine Inc.’s Mobile Avian Radar System – MARS. The Plano, Texas-based company’s proprietary system makes it possible for scientists to count migratory birds flying through airspace they might some day share with wind turbine blades.

The radar system is capable of providing scientists with information to determine bird species without actually seeing the animals.

Geo-Marine is a pioneering company in real-time bird migration survey monitoring. The company also develops bird-aircraft strike hazard and bird-related risk-management data.

Migratory bird information is just one item requiring study to determine the offshore wind farm’s potential environmental impact.

A hydraulic system extends the Peterson’s legs to the bay floor. Rack-and-pinion gearing on each leg lifts the boat above water making it a platform unaffected by wave action.

“We disconnect the vessel from the sea and stabilize it at a fixed level and position,” said Dave Morgan, Aqua Survey’s director of engineering and one of the Peterson’s crewmembers.

Morgan, a marine engineer, said test borings done earlier at the bird-survey site provided an opportunity to check out the bay floor in advance.

“The bottom there is very sandy. We’re confident it’s stable,” he said. Morgan said oil companies use vessels like the Peterson, commonly called lift boats, to conduct offshore seismologic studies.

He said separating the vessel from water-generated motion is essential when conducting research requiring a stable base.

“When the boat is lifted we create an air gap beneath plus a little margin,” Morgan said.

Before it became the Peterson the boat worked off the coasts of Louisiana and Texas.

Clement said the vessel has been modified – its legs have been cut from their original 105-foot length – to make it more suitable for the current job.

He said shortening the legs was also necessary to make the trip to Delaware possible.

“We used the Intracoastal Waterway, which has a minimum bridge height of 65 feet. We would lower the legs to go under the bridges,” Clement said.

He said the Peterson’s legs were lowered into the Delaware Bay for an overnight stay before coming to the city dock.

Clement said at the overnight location the boat’s legs pushed deep into the bay’s muddy floor.

He said it sometimes takes several hours to lift legs mired in mud. He said the Peterson is equipped with a tilt alarm that warns the crew when the legs are down and the boat begins to list excessively.

“Stability is not absolute. Sometimes you have to get up in the middle of the night and level it,” Clement said.

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