By listening for the calls of right whales in the waters of New England, researchers are helping ships avoid the endangered animals.
Ten whale detection buoys are now in place in the busy shipping lanes leading into Boston Harbor, a hot spot for ship strikes. When the buoys pick up the calls of North Atlantic right whales, warnings are sent to ships in the area so that they slow down. It’s the first time that a listening system has been coupled with real-time warnings.
“I have been just immeasurably excited and impressed about how well it’s worked,” saysChristopher Clark, a senior scientist at Cornell University, who helped develop the system. Spring is the busiest season for right whales in the waters of New England. “For the last couple of months, it’s just been bonkers,” Clark says. “There’s a lot more going on out here in the shipping lanes than we ever thought.”
The buoys were installed at the beginning of the year in Massachusetts Bay as part of the licensing requirements for a liquefied natural gas (LNG) import facility 13 miles east of Boston. The area is both a popular hangout for right whales and part of the route for LNG tankers and ships headed to and from Boston. LNG tankers are required to slow to 10 knots if right whales are detected in the area.
“We think it’s working extremely well,” says David Wiley, research coordinator for the Stellwagen Bank National Marine Sanctuary. “The detections are being sent out, and we know the LNG ships are slowing down” at the mouth of the bay.
Only about 400 North Atlantic right whales remain on the planet. Ship strikes are a major source of mortality because the whales spend a lot of time feeding at the surface. “The whales are very docile,” says Don Peters, a senior engineer atWoods Hole Oceanographic Institution, who worked on the project. “They tend not to be very shy of boats. They won’t spook and swim away if a boat is coming toward them.”
Within the past three years, at least two North Atlantic right whales have been killed by ships in the area, says Leila Hatch, regional marine bioacoustic coordinator for the sanctuary. “This is in a population where we cannot lose one,” she adds.
The whale detection system cost $1.3 million up front, and will absorb another $25 million in maintenance costs over the minimum of 25 years that the LNG facility is expected to operate. “It’s definitely an expensive tactic, but it’s something that the shipping industry has accepted,” says Hatch.
The detection buoys are positioned five miles apart so that “when a whale calls in the area, it’s picked up by more than one buoy,” says Peters. “There are no dead spots.” Suspended 50 feet below each buoy is a hydrophone, which is linked to the floating buoy by a reinforced rubber hose, designed to reduce extraneous noise from the mooring. This “gumby hose,” as the developers call it, can stretch to more than 100 feet, keeping the hydrophone steady in rough waters.
Cables embedded in the gumby hosetransmit sound signals from the hydrophone to a surface buoy containing a processor and software that analyzes underwater noise. Sounds are rated on a scale of 1 to 10, according to how likely they are to be right-whale “upcalls,” which the animals use to keep tabs on each other.
“A right whale has a real hard time keeping its mouth shut,” Clark says. “They call to say, ‘Is there anybody out there? Is there food over there? Do you want to get together? What’s going on?’”
Sounds that are likely to be right-whale calls–rated at least 6 out of 10–are sent via satellite to Cornell to be checked by research assistants. Packages of two-second audio files are sent every 20 minutes, so during the busiest season, when whales and calves congregate in the Northeast, thousands of clips come in every day.
When LNG tankers are in the Boston area, Cornell’s whale listening team works around the clock. Otherwise, the clips are checked twice a day. Clark admits that he has developed an addiction. “They call me the ‘clip-checking fairy,’” he says. “I can’t help myself.”
Soon LNG tankers will automatically receive warnings from whale detection buoys, but until that part of the system is up and running, “I’m calling the captain of the ship and saying, ‘You’ve got whale,’” Clark says. The information is also distributed via fax and e-mail as part of the Right Whale Sighting Advisory System, which also includes sightings gleaned from aerial surveys. Information from the buoys is also available on a public website.