Orcas are under threat from man-made noise pollution. These scientists are fighting to protect them.

• Experts are studying how man-made noise pollution, like from boats and oil drilling, is threatening the lives of orcas.
• One team of scientists is collecting hundreds of hours of orca recordings off the coast of Norway in an effort to make to region a marine protected area.
• Man-made noises interfere with orcas' communication, which they use for hunting and mating.
• And orcas trying to escape the underwater cacophonies may travel too far to the rocky shoreline, which can result in stranding and death.

Orcas have a language of their own. They communicate through touch, movement, and most importantly, sound.

And it's marine scientist Ellyne Hamran's job to eavesdrop on them.

Hamran is an acoustic researcher studying the sounds marine mammals like whales and dolphins use to communicate. She's captured hundreds of hours of orca recordings.

This summer, she's listening to the orcas of Norway's Lofoten Islands, beloved by the creatures for its healthy populations of herring and other fish to feed on.

But an invisible problem is increasingly alarming experts: noise pollution from whale-watching cruises, oil exploration, and other human activity. Hamran has set out to study how it affects the whales — and use her findings to make Lofoten a marine protected area, permanently shielding it from both unwelcome noise and oil drilling.

"Whales are using sound as their primary sense, unlike humans that are using their vision," Hamran told Business Insider Today. "So it's very important for whales to be able to communicate to each other, to find mates, to search for prey, also to navigate the area."

Hamran works for Ocean Sounds, a nonprofit that advocates for marine ecosystem conservation and has been tracking orcas here in Lofoten since 2003.

On a typical day, Ellyne, her husband Bjørn, their dog Bailey, and a team of researchers drive around the islands in an inflatable boat looking for action.

When they spot whales, they slowly approach, then turn off the engine to minimize noise. They use an underwater microphone called a hydrophone to record vocalizations.

"During socializing, they're producing a variety of vocalizations. It can be whistles, calls, buzzes, clicks — same with when they're feeding. They're a little bit more quiet when they're traveling," she said.

They also photograph the whales to keep track of the family groups. Bjørn operates a drone that films whales from above. The scientists assign a number to each orca and add them to a catalog.

"We will be able to use this method to track them over time. It's a very noninvasive and inexpensive way of doing the research," Hamran said.

Over time, they match the orcas' sounds up with behaviors, gradually learning their complex language. Each pod speaks its own dialect, so tracking them is essential for understanding the communication.

The large population of whales also attracts thousands of people looking for boat tours every year. But these ships full of whale lovers can actually be quite disturbing to ocean life.

"We've had issues of boats zooming through pods, sometimes even between the mother and calf," Hamran said. "It's also quite loud on the hydrophone, even loud enough that you want to turn the volume down, but the whales are not able to go in and modify how loud the boats are. And I don't think people are aware of this issue."

Boat noise can overpower whale calls — "it could mask the vocalizations that they can't be able to communicate with each other nearby or find a mate," she said.

And it can scare away the fish orcas feed on, too.

"They spend quite a lot of time rounding up the herring to feed, and then a boat could come way too close and now disperse the fish," she said.

The looming threat of oil drilling also poses a problem. In 2019, the Norwegian government reached a deal to block drilling in Lofoten for now. But every seat in the parliament is up for election in September 2021, which could put the area at risk again.

And even without permission to drill, companies can still use blasts of compressed air to map where oil lies beneath the ocean floor.

These seismic surveys can be louder to marine life than fireworks from 3 feet away.

Researchers aren't sure how these sounds affect ocean mammals' health, but studies have found that a single seismic airgun survey can be heard underwater for months.

All this, combined with occasional military exercises in the area, creates an underwater cacophony that interrupts whale communications.

Because orcas are instinctively collaborative, communication is central to everything they do. Disoriented whales may also swim out of their usual living area — Hamran said the whales often swim dangerously close to the rocky coastline to get away from the boat noise.

Ellyne says this may explain why the spring of 2020 saw more whales stranded on the coasts than any previous season.

The strandings could also have been caused by a harmful algae bloom or a virus that affected several species. But unless Ellyne and the team can examine a stranded whale shortly after its death, they can't gather much information. Typically they need to arrive within 48 hours of the stranding or else the animal will have decayed too much.

Ultimately, Ellyne's findings support Ocean Sounds' efforts to educate the public about protecting the mammals.

Ocean Sounds has a set of guidelines for whale-watching boats that they're advocating to turn into Norwegian law. They include requiring boats to slow down and turn off the engine while approaching whales — and maintaining a minimum distance of 300 meters at all times.

Achieving their goal of having Lofoten named a marine protected area would shield marine mammals from all forms of manmade noise pollution, not just boats.

Until that happens, Ocean Sounds is selling recordings of whale communications online as a way to raise awareness and fund their operations.

"We're trying to be able to not only study the vocalizations and behavior, but also to bring the whales to the people, giving a voice to the whales," she said.