This story ran in the recent issue of Oceana magazine.
The waters of the mid-Atlantic are alive with sound. The snaps, squeaks, bubbles, pops, and whistles of marine life ring through the water, interspersed with the low calls of North Atlantic right whales. But this chorus of sound may soon be drowned out.
Already the right whales’ calls are few and far between. The North Atlantic right whale is the rarest of the world’s large whales and one of the most endangered species in the United States. Decimated by intensive whaling in past centuries, there are now only an estimated 500 whales in the waters off the east coast. Right whales earned their name because they were easy to harpoon and float when dead, making them the “right” ones for whalers to target. Though no longer hunted, the population is still struggling to recover because this surface-dwelling species is especially vulnerable to being struck and killed by ships.
Right whales migrate along the East Coast twice each year, traveling between breeding grounds in the south and feeding grounds in the north. In winter they breed and calve in the warm waters off of Georgia and northern Florida, and then migrate north to feed during the summer on plankton in the cooler waters between New York and Nova Scotia. Unfortunately, this annual migration route puts right whales directly in the path of both heavy shipping traffic and planned oil and gas exploration.
The Bureau of Ocean Energy Management (BOEM) is planning to allow energy companies to use seismic airguns to search for offshore deposits. These devices map the seafloor by shooting pulses of compressed air through the water every 10 seconds, creating a map from the reflected sound waves.
“They blast constantly for weeks on end, and are extremely harmful to marine mammals like right whales,”says Matthew Huelsenbeck, a marine scientist with Oceana, “because they rely on sound to communicate, feed, reproduce, and migrate.” The government estimates that seismic airguns will injure at least 138,000 dolphins and whales if they are used in the Atlantic.
As part of the decision-making process, BOEM is required to prepare an Environmental Impact Statement, or EIS, that analyses the effects airguns would have on marine life and outlines protection plans for endangered species, like the right whale. “But Oceana-funded research revealed that BOEM’s initial mitigation measures would be completely inadequate,” says Claire Douglass, Oceana’s campaign director for climate and energy.
In partnership with the International Fund for Animal Welfare, Oceana funded a two-year study of North Atlantic right whales off the coast of Virginia, conducted by scientists from Cornell University’s Bioacoustics Research Program. Their Right Whale Listening Network gathers data about right whale occurrence along the eastern seaboard. “We want to paint a continental-scale understanding of what right whales are doing and when they are in particular locations,” says program director Aaron Rice.
But because the mid-Atlantic was thought of as just a migratory corridor, Rice says, researchers had little data about where and when right whales occur in Virginia waters. To fill the gap, Rice and his colleagues deployed six marine autonomous recording units, or MARUs, along the continental shelf off of Virginia Beach in 2012. These battery-powered hydrophones, or underwater microphones, record ocean noises continuously for six months—capturing what Rice calls “the soundscape of the ocean.”
After six months the MARUs are hauled up and swapped for fresh devices, so Rice and his team can analyze the recordings. A computer program, aided by human analysts, sorts through up to 100,000 hours of data to find right whale calls. Rice says that unlike humpback or bowhead whales, right whales don’t sing long, dramatic songs. Instead, they have several types of short noises, including a moan, a rumble, a gunshot sound, and an up-call, also called a contact call. Rice and his team use these up-calls to tell exactly when and where right whales are in the recording area.
“The first thing that we noticed was that we had right whales all over the place,” says Rice. The researchers expected to detect right whales during a few weeks in the spring and fall, when they migrated through the area. But initial data reveal that right whales are staying in Virginia waters year-round. Also surprising is where the right whales are found offshore—the data show right whales spread widely across the continental shelf, between 18.4 and 72.5 miles offshore.
“Rice’s discovery is worrying, because it means the government’s plans will not adequately protect right whales from seismic airguns,” says Douglass.
Before BOEM published the EIS in February, Douglass and others at Oceana met with their science team to discuss Rice’s new data. “We wanted to make sure that the decision makers have the most up-to-date science,” she says. “Unfortunately,” Douglass says, “BOEM chose to ignore the science in their EIS, which means this critically endangered species will not be protected.”
After reviewing Rice’s data and Oceana’s concerns, BOEM revised the EIS to include the new data about Virginia right whales, says Douglass. They included time-area closures for right whales and loggerhead sea turtles, acoustic monitoring and visual surveys, and shut-down procedures for when a marine mammal is present.
While Douglass is glad that BOEM incorporated the new information into their protection measures, she says that even with these precautions, airguns will still harm right whales and many other marine species if they’re allowed in the Atlantic. “Rice’s research shows that we know so little about these whales that we shouldn’t be considering seismic in the first place,” she says.