OREGON STATE UNIVERSITY

OSU scientists to study whale-deterring sounds

05/05/2010

NEWPORT, Ore. – Scientists from Oregon State University’s Marine Mammal Institute will begin a project in December to test whether a low-power acoustic deterrent device can prevent migrating whales from entering a 500-meter-radius area of the near-shore ocean that may eventually contain wave energy platforms and cables.

Funded by the U.S. Department of Energy, the project is the first step toward reducing potential risks of wave energy to marine mammals, said Bruce Mate, director of the OSU institute and an internationally recognized expert on whales.

“This won’t answer all of the questions,” Mate said, “but it will give us a better idea if low-level acoustics can be used as a tool to help protect the whales by moving them small distances out of harm’s way.”

In an effort to inform citizens, fishermen and other ocean users about the project, OSU’s Hatfield Marine Science Center will host a community forum on Wednesday, May 12, from 7 to 8:30 p.m. in the Hennings Auditorium. Speakers will describe the study’s methodology and outline the type and frequency of the sounds that will be used in the project. There will be time for questions and dialogue.

Mate said that many of the concerns voiced about wave energy’s potential impact on whales involve entanglement in cables, but that risk is minimal because the cables would be rigid and have tens of thousands of pounds of pressure on them. However, migrating whales travel at a speed of about four miles an hour and running into a four-inch to six-inch thick cable – or mooring platform – could cause traumatic injury, he pointed out.

“If an acoustic device can successfully reroute whales in a minor way on their migration, the implications go beyond wave energy,” Mate said. “The technology could be used to prevent whales from entering waters with environmental risks, for example, such as oil spills.”

Mate has spent much of his 41-year career studying endangered and threatened whales and pioneered the use of satellite tags to help track marine mammals. His research on different whale species’ migration routes, diving patterns, and breeding and calving locations has greatly enhanced the ability of resource managers to protect the animals.

The four-month pilot project, which begins in late December, will target gray whales, which are the predominant large whale species in Oregon’s near-shore waters. A 2008 study by Mate and Joel Ortega found that 61 percent of migrating gray whales sighted off the coast passed within Oregon’s Territorial Sea, which is within three nautical miles of the shore.

The scientists will place an acoustic device on a mooring just west of Yaquina Head near Newport which will emit a low-pitched one-second “whoop” sound three times a minute during a six-hour stretch each day. The sound energy will be less than 1 percent of sonar emitted from a single fishing boat, the scientists say, but hopefully it will be enough to subtly influence whale movement, Mate said.

“We do not even expect gray whales to react to the sound unless they are within 500 to 750 meters of the mooring location,” Mate said. “We’re not talking about much sound here. Although baleen whales, including grays, don’t have sophisticated sonar, they are good listeners, so we hope it will alert them to be more aware.”

The researchers have applied for a permit from the National Marine Fisheries Service for the project to test the acoustic devices – the same level of permit required for flying an airplane over the water to count whales, or photographing whales during a ship-based survey.

Mate said the acoustic device would emit one-eighth of one watt, which they hope will make the whales alter their paths about 500 meters from the noise.

Gray whales generally migrate past Yaquina Head twice a year. In December, whales begin heading south toward breeding and calving areas and tend to be farther offshore. They return in two “waves” – singles in March and April, and then north-bound mothers with calves in May, usually within a half mile of shore. The researchers will conduct their north-bound acoustic tests on the single whales and not the mother-calf pairs that travel closer to shore, Mate said.

“Ideally, we’d like to see the whales respond to these pings by moving about 500 meters around the device, which adds just a tiny bit – one hundredth of one percent – to their migration distance,” Mate said.