A strange "ping" is emanating from the Arctic Ocean, according to reports from hunters and boaters in Canada's Nunavut territory. The noise has been occurring for months, dating back to summer, and it correlates with fewer sightings of marine animals nearby. Some local hunters worry it's scaring away wildlife.

Also described as a hum or beep, the mysterious sound seems to come from the seabed in the Fury and Hecla Strait, a narrow channel in the Qikiqtaaluk Region of Nunavut. It's a remote area, about 120 kilometers (75 miles) from the hamlet of Igloolik, located within a stretch of open water surrounded by sea ice. Known as a "polynya," this type of habitat is normally a popular hangout for wildlife.

"That's one of the major hunting areas in the summer and winter because it's a polynya," Nunavut legislator Paul Quassa tells the CBC. "And this time around, this summer, there were hardly any [animals]. And this became a suspicious thing."

map of Igloolik The mysterious ping has been reported in an area about 120 kilometers (75 miles) northwest of the hamlet of Igloolik, which is marked with a red dot in the map above. (Image: Wikimedia Commons)

Concerned for local wildlife, Quassa recently addressed the Nunavut legislature about the sound, which he said is "emanating from the sea floor." A community radio show has also received calls from people who say they've heard the ping, including some who reportedly heard it through the hulls of boats.

The reports inspired another legislator to visit the area, too, and while he says hearing loss may have prevented him from hearing the sound, he did notice the absence of animals. "That passage is a migratory route for bowhead whales, and also bearded seals and ringed seals," George Qulaut tells the CBC. "There would be so many in that particular area. This summer there was none."

Sound travels relatively well in the ocean, and marine mammals often rely heavily on their sense of hearing, including many dolphins and whales. Underwater sonar is known to cause serious problems for a variety of sea creatures, so if these reports are accurate, it would make sense for the sound to affect wildlife.

Stranger pings

bowhead whales Bowhead whales are known to frequent the area where the noise has been reported. (Photo: Vicki Beaver/NOAA)

The source of the sound remains unknown, but several theories have surfaced. One suggests it's related to sonar surveys by the Baffinland Iron Mines Corporation, which mines iron ore from Canada's Baffin Island. The company tells the CBC it isn't surveying in that area, though, and has no equipment in the water. Quassa says Nunavut hasn't issued any local work permits that might explain the noise.

Another theory goes a very different direction, accusing Greenpeace of generating the ping on purpose to drive animals away from the polynya, thus protecting them from hunters. Yet Quassa says there's no evidence the environmental group has ever used sonar to disrupt Inuit hunts, and Greenpeace also denies any involvement.

"Not only would we not do anything to harm marine life, but we very much respect the right of Inuit to hunt and would definitely not want to impact that in any way," Greenpeace spokeswoman Farrah Khan tells the CBC.

All this attention finally got a response from Canada's Department of National Defence (DND), which sent military aircraft to investigate the area this week.

"The Canadian armed forces are aware of allegations of unusual sounds emanating from the seabed in the Fury and Hecla Strait in Nunavut," DND spokeswoman Ashley Lemire says in a statement. "The air crew performed various multi-sensor searches in the area, including an acoustic search for 1.5 hours, without detecting any acoustic anomalies. The crew did not detect any surface or subsurface contacts."

The crew did, however, "observe two pods of whales and six walruses in the area of interest," Lemire adds. That doesn't necessarily mean the sound is gone, or that it isn't affecting wildlife, but "at this time, the Department of National Defence does not intend to do any further investigations," she says.

Sea something, say something

polynya off Antarctica Polynyas, like this one in Antarctica, are areas of unfrozen ocean surrounded by sea ice. (Photo: Jeff Schmaltz/NASA)

Speaking to the Nunavut legislature on Thursday, Quassa thanked the military but also expressed doubt that we've heard the last of this ping.

"We want to thank the Department of National Defence for doing an investigation right away," he said in Inuktitut, according to the CBC. "I know that they will keep investigating this and they will be kept informed by the hunters as well. I encourage hunters to keep telling the Department of National Defence what they hear."

The ocean has a long history of surprising people with strange noises, from eerie choruses of singing fish to large whistling waves that can be detected from space. Earlier this year, researchers detected a subtle "buzzing or humming" sound in the remote Pacific Ocean, and could only speculate about its source.

Even if such noises usually turn out to be natural and harmless, staying attuned to our natural environment is always a good idea, Quassa added. Strange sounds, sights and smells could provide an early warning of some undiscovered ecological problem, and people who live nearby are the first line of defense.

"Sometimes there are mysterious things, and there are people who report those mysterious things," he said. "I want to thank them."

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.