Article |

From Whaling to Drones: The Science of Cetaceans

From humpbacks to belugas and bottlenoses to fins, whales are some of our favourite wildlife sightings. Learn about the fascinating biology of cetaceans and the latest technological advancements that are helping protect these special underwater creatures.
Humpback whale Trinity Bay Newfoundland

© Dennis Minty

It’s Not Easy

Imagine what it’s like being a cetacean scientist. Your subjects are spread throughout a vast, three-dimensional ocean environment and, even if you have chosen to be in the right spot at the right time, you only get a glimpse when they rise to breathe. You can’t trap them or tranquilize them. Getting blood samples is almost impossible. You can dive with them, but you need their full cooperation. Some are so rare or stay submerged in deep water for such long periods that all you get are momentary flashes of their lives at the surface.

As recently as 2019, a new species was discovered near the coast of Japan (the black Baird's beaked whale, Berardius minimus). Imagine that! A whale—not some tiny protozoa—newly discovered!

Feeding humpback whales

© Dennis Minty

When the International Union for the Conservation of Nature published their Species Red List (a list of species considered endangered) in 2017, 50% of cetaceans could not be evaluated because of the lack of data.

It’s difficult and expensive to answer questions such as, where do whales go? What do they eat? How many are there? How do they find each other? Do they communicate? How do they find their food? It’s even more difficult to determine the effects on whales of warming oceans, overfishing, acidification, oil pollution, and seismic technology used by the oil and gas industry.

All this is to say that cetacean scientists are still just scratching the surface of what we know about these mammals that started on land and have become such masters of the sea. Much of what the scientists would like to know still stretches before them. Nonetheless, in the scratching, they have discovered some fascinating things about these elusive creatures, and new technology is helping.

Humpback whale close up near surface

© Dennis Minty

The jaw of a humpback whale seen close to the water's surface

From the Days of Whaling

Our whale knowledge got started during the hard days of commercial whaling, which has a bad reputation in today’s world but was a respectable, even admirable, occupation in its heyday. Richard Ellis in his book Men and Whales said, “…it is only through the lens of hindsight that the whaleman’s job becomes malicious or cruel… “

It was not only respectable, but quite lucrative too. A young man could return from a whaling season in South Georgia, for example, with enough money to give his life a jumpstart and buy a house, start a business, or build a fishing boat.

Whaling vessel Grytviken South Georgia

© Dennis Minty

Grytviken, South Georgia

Perhaps with our present fascination with whales and our rightful ecological consciousness, we have forgotten why commercial whaling was so important at one time, economically-speaking. Whale oil once provided the primary source of light for much of the world. It lit homes and factories, churches and lighthouses, and the headlamps of miners. It helped extend the length of the working day, thereby contributing to the industrial revolution. It provided evening light to allow reading and family gatherings after dark.

It lit the world for 300 years until it was replaced by petroleum, and eventually electricity. Whales provided other products too, but light was the most important benefit. Whales were the only animals ever exploited as a commercial energy source.

Commercial whaling gave us our first insights into cetacean natural history, with each animal providing a still “snapshot” of that whale’s life and condition. It gave us the first information about whale distribution and seasonal movements. We learned which whales were the best ones to kill, how to identify them by their blow, back, and tail, and which whales provided the best harvest of oil. Each whale hunted provided insights into the species' anatomy, function, and food.

Whaling community Grytviken South Georgia

© Dennis Minty

Grytviken, South Georgia

A Taste of What We Know

More recently, with the help of modern technology, we are beginning to be able to stitch together these snapshots into moving pictures that show us more about adaptations, behaviour, and ecosystem relationships.

Perhaps you know that the blue whale is the largest animal that ever lived, but can you really picture how big it is? It is as long as three school buses parked end to end. I’ve only seen one in my life, and it was so big that my first impression was of an island rather than a whale. Its arteries are the size of drainpipes. A football team could fit in its open mouth. So, there you have it: most whales are big, but I suspect you knew that already.

Humpback whale

© Dennis Minty

How is it that a mammal can hold its breath so long—nearly four hours in the recent case of a Cuvier’s beaked whale? Surprisingly, the size of their lungs in relation to their bodies are smaller (only 3% of the body cavity) than a human’s (7%). Bigger lungs would not work anyway, because filling them would cause the whale to become too buoyant to dive.

Here’s how they cope: as soon as a whale surfaces, it exhales in a forceful blow and gets rid of about 80-90% of the spent air. (In contrast, we dispose of about 15% with our much tamer exhalations.)

Another of their adaptations has to do with their blood. For starters, they have more of it per unit of weight than most other mammals, but it also carries more oxygen per unit volume, thanks to much higher levels of haemoglobin. Oxygen is stored in muscle using myoglobin, and whales have 30% more of it than terrestrial mammals. This means their blood and muscle are both supercharged with oxygen, giving them an adaptive edge.

Humpback whale blow hole close up

© Dennis Minty

They also slow their heart down. Stanford University scientists were able to measure the heart rate of a blue whale for the first time in 2019. During a dive it went as low as two beats per minute!

Along with the lower heart rate, whales can shunt blood flow away from parts of the body that don’t need it during a dive, like the skin and digestive tract, while ensuring that the brain and heart continue to get enough oxygen. With these respiratory and circulatory adaptations, deep-diving whales actually exhale when they dive so as to minimize their buoyancy.

We breathe involuntarily so that even when we're unconscious, breathing continues. But not so for whales, who breathe voluntarily. So, how do they sleep? Turns out they can rest half of their brain at a time while floating quietly at the ocean's surface, in a process known as logging.

Northern bottlenose whale

© Dennis Minty

A northern bottlenose whale, a deep diver in the world of cetaceans

Whale Songs

We have known for centuries that whales vocalize, some much more than others. But it was in the 1960s that whale biologist Roger Payne captured the haunting, complex sounds of humpback whales with a hydrophone and, while listening to them over and over, realized that they were repeating patterns—songs.

Inspired and moved, he gave the recording to Judy Collins who released her album in 1970 called Whales and Nightingales, which included the song “Farewell to Tarwathie” with the whale vocalizations in the background.

This was one of the first albums in my record collection and I remember, as a young biology student, being absolutely entranced by that song with the whales. Vocalizations so complex and persistent had to be involved in sophisticated communication. It was still early days in raising people’s consciousness about whale conservation and this album was a milestone along the way.

The record went gold and introduced millions of people to humpback whales for the first time. People woke up to the idea that whales were complex, intelligent beings and that humankind was killing them off. Then, in 1982, the International Whaling Commission banned deep-sea whaling.

Humpback whale tail with markings

© Dennis Minty

Some whale sounds are very loud and can travel long distances in water. How loud and how far? A human talking voice is measured at 60 to 70 decibels. The threshold for pain in the human ear is at about 120 to 130 decibels. A jet engine produces about 140 decibels. A blue whale makes a sound that is 188 decibels and that can be heard from hundreds of kilometres away.

Research on fin whales has shown that they can hear each other over nearly 1,000 kilometres. Just think about that! Whales could be hundreds of kilometres apart and communicating with each other as part of a social group.

But ambient noise in the sea is increasing from ship traffic, sonar, and seismic testing. Who knows how this is affecting whales and their communication with each other? In fact, in 2017, the community of Clyde River, Nunavut won a case in front of the Supreme Court of Canada, arguing they had not been properly consulted when the National Energy Board allowed oil companies to seismically test the ocean floor around their homelands.

The community argued that the practice would adversely affect the marine life that they relied upon for hunting, gathering, and maintaining their traditional way of life. (Unlike the environmentally harmful commercial whaling practices of recent history, many Inuit communities continue to sustainably harvest whales today, which feed entire communities and keep people connected to their traditional culture.)

Some of the sounds that whales produce are for echolocation. These are often high-pitched clicks that bounce back and provide important information, such as prey size and location. Beluga whales make an astounding array of sounds, some of which are for echolocation, while some have other functions. But their whistles, clicks, squeals, and chirps have led to their nickname as sea canaries. As animals of the dark winter, being able to communicate, navigate, and find food by sound is essential.

Humpback whales Disko Island

© Dennis Minty

Humpback whales hunting along an ice wall, Disko Bay, Greenland

New Technology

With whales occupying such remote areas of the planet, it’s incredibly difficult to know where and how many there are. Photography from space using satellites is helping scientists fill some of the gaps in our knowledge base. They are using imagery, such as that used for Google Earth, to determine if they can count and classify whales from space. But from all the millions of satellite images available, which ones do you look at to scan for whales?

Convolutional Neural Networks (CNNs) to the rescue! Theoretically, CNNs can automatically scan images to detect and classify objects like whales. And the more whales they detect and classify, the smarter they get at doing so.

In 2019, Emilio Guirado and his colleagues from the University of Granada published a paper that tested and proved the concept. Whales were successfully detected and counted at known hotspots, but evaluating all the oceans is another level of sophistication presently out of reach. (However, with supercomputing power, perhaps not impossible for much longer.)

Orca killer whale

© Dennis Minty

Drones have opened whole new worlds of scientific investigation power; some would say that they are allowing a paradigm shift, even a revolution. Remote sensing, as done by drones, is important because whales are already under stress. In trying to learn more about them, we don’t want to cause more harm. Yet to implement effective conservation measures, we need more and better data. Drones are helping to solve this catch-22.

One frustrated marine scientist, Iain Kerr, was trying to collect a tissue sample from a sperm whale using a big needle on a long pole that could pluck out a pencil-sized specimen. Each time he readied his equipment to take the sample, the whale blew, covering him with stinky mucous, then it would dive and disappear for about 45 minutes. He described it like standing in a cold shower and ripping up hundred-dollar bills.

It inspired him to develop the Snotbot, a drone used to sample droplets from a whale’s blow, which can be used to extract DNA, look at hormones, and sample the bacteria that are expelled with every breath. Unlike the big needle tissue sampler, it is non-invasive and stress-free for the whale, while also keeping the scientist out of harm’s way. A few passes through the blow can yield plenty of data.

Whales close to boats

© Dennis Minty

The use of a drone can be twenty times less expensive than more traditional methods. It is so cost effective that it opens the door for scientists in coastal nations of the developing world to undertake whale studies.

Drones with infrared cameras are being developed to be able to take a whale’s temperature through its blowhole. Others are being used to take accurate measurements of a whale that will allow an evaluation of a whale’s overall condition and health. Much of this work is being done by Ocean Alliance, founded by the same Roger Payne who recorded that humpback song.

Aside from the flying drones, there are now solar- or wind-powered unmanned sailing vessels that can operate for months at a time. They are primarily designed to collect atmospheric and oceanographic data, including data on fish stocks. But they can also be equipped with acoustic devices tuned in to the vocalizations of the whales and can survey large areas because sound travels so well through water. Presently they are being used as listening devices to monitor endangered right whales in the north Pacific.

Normally this kind of work would need to be done from larger, expensive research vessels. The floating drone follows a programmed track as it is constantly listening. First time out, they were not as successful as hoped, but they are working out the kinks and they hold great potential.

Humpback whale blow

© Dennis Minty

On Seeing Whales

On an expedition with Adventure Canada, you’ll have plenty of opportunity to see whales. When we see one, the first question is always: what is it? Even experienced whale observers must look carefully to figure this out.

First, we look at the blow. Is it bushy or cone shaped? Does it go straight up or off at an angle to the head? How tall is it? What is the interval and frequency of the blows? Sometimes you see the head along with the blow. Does it have a forehead or is it sloped? Can you see a snout or beak?

Beluga whales in St Lawrence River

© Dennis Minty

Beluga whales, Saguenay River Estuary

Then, the back appears. Is there a dorsal fin or not? What’s the shape of the dorsal fin? Do you see the blow and the dorsal fin at the same time? How big is the back and what colour is it?

Finally, you might see the tail. Does it rise above the water? What is the shape? Does it have markings or not?

You must assemble all these observations to generate an identification and it takes a lot of experience to become good at it. The more time you spend outside on deck, the more likely you will see one of these fascinating creatures still so shrouded in mystery.

About the Author

Dennis Minty

Dennis Minty

Photographer, Wildlife Biologist

Dennis has been working with Adventure Canada since 2002. Dennis’s path—from his small island roots in Twillingate, Newfoundland to his current career as a photographer and eco-tour leader—has taken him through more than three decades of local and international work.

For him, nature and photography are inseparable. Dennis immerses himself in nature through photography and seeks to inspire in the viewer a deeper connection with the natural world. Dennis has authored nine books on subjects such as environmental science, his home province of Newfoundland and Labrador, and his photography.

To see more of Dennis' work, visit his website.