Features

A Sea of Sound

BC Whales | North Coast Cetacean Society

Words by Lauren de Vos

Cover image

Photo by Fabien Michenet | BiosPhoto

I hear them long before I see them: a high-pitched whistle as I sink my head below the water, the trill of an aquatic Mozart’s Zauberflöte directing my attention to the right. A volley of staccato clicks follows, seconds before a chattering pod of Indo-Pacific bottlenose dolphins swims into view. Off the coastline of Mozambique, this resident group of social dolphins flouts immigration laws as it traverses the invisible border that marks the end of South Africa at Kosi Bay and the start of Mozambique at Ponta do Ouro. I’m swimming in surround-sound, squeaks and whistles filling the water around me. The well-spotted underbelly of an aged male flashes past, his clarinet contribution to the swell of signature voices taking a momentary lead in this overture. The breathy fluting of two mothers follows, their calves piping piccolos close at their sides.

Suddenly, Monostatos’ metallic whirr cuts through the calls in this marine performance of The Magic Flute. A propeller’s percussive clack-clack-clack slicing through the water is the prelude to the low engine hum that drowns the voices of the group. With a start, I realise that it’s the boat moving closer to retrieve me from the water. I lose my bearings in relation to the group and although it is still nearby, I can’t locate it as easily as when I could hear it. The dolphins quickly outpace me and, even in this clear water, without their sonic cues to guide my gaze, I soon have to concede that I’ve lost them.

Acoustics guide marine life; it is sound that helps species navigate, hunt, hide from predators, find mates and communicate with each other. The ocean soundscape isn’t only made up of calls from different animals, but includes ambient levels of noise from crashing waves and ocean spray, rainfall, and bubbles that form and burst. Somewhere in this oceanic orchestra, the strains of human activities – commercial shipping, seismic exploration, the back-and-forth of recreational vessels – are increasingly heard and, in many cases, overpower the sea’s other voices. As the number and size of ships traversing the ocean has increased, explains John Hildebrand from the Scripps Institute for Oceanography in his 2009 paper for the journal Marine Ecology Progress Series, ambient ocean noise levels have risen by 12 decibels.

For the humans that are temporary visitors to the ocean’s depths, noise pollution is relatively inconsequential. My own survival, for instance, wasn’t linked to losing earshot of those dolphins on the day the inflatable boat purred over to collect me off the coast of Ponta Malongane. For many ocean animals, however, noise is the ironically silent pollutant in the oceans today, its insidious impacts less frequently discussed than those of plastic and oil spills.

Cover image

Photo by Fabien Michenet | BiosPhoto

Janie Wray Project Leader - Founder of the North Coast Cetacean Society (NCCS)

Lauren de Vos Project Leader

Photo by Fabien Michenet | BiosPhoto

Hildebrand goes on to explain how ocean construction, oil exploration and seismic surveys have moved gradually into deeper waters, extending their sonic reach far from the coastline and into the abyss. There is less and less ocean that remains ‘out of earshot’ of human activities. Seismic surveys generate low-frequency noises that travel long distances across entire ocean basins. The lower the frequency, the less it attenuates and the further the sound travels. Reports abound of cetacean strandings or disturbance after offshore seismic surveys, but the causal evidence that links these deaths with noise pollution remains scant. This reflects a need for more comprehensive study and analysis and is not an indication that convincing evidence doesn’t exist, say Manuelle Castellote and Carlos Llorens, the authors of the chapter ‘Review of the Effects of Offshore Seismic Surveys in Cetaceans: Are Mass Strandings a Possibility?’ in a 2016 publication on the effects of noise on marine life.

Sound pollution means different things for different species. Whereas some noises can damage the hearing (and even non-hearing) tissues in the bodies of marine animals, others mask auditory cues in the marine environment that help animals find each other, locate their prey or navigate their way. Some sound pollution can even change hormone levels, resulting in stress and sleeplessness, according to Hansjoerg Kunc, Kirsty McLaughlin and Rouven Schmidt in a 2016 publication on the impact of aquatic noise on marine animals. While the impacts of blasting, oil exploration and seismic surveys are extreme and often deadly for ocean animals, far more pervasive is the noise from shipping and boating, which is ubiquitous and frequent in our oceans. This kind of noise may not directly kill marine life, but it can disrupt animals’ ability to navigate, find mates, hunt prey or escape predation. Some of its impacts even affect animals that don’t obviously employ sound in their life-history strategies. In a 2014 study, scientists showed how the common cuttlefish Sepia officinalis adjusts its complex visual communication display by changing its colour more frequently in response to noises from human sources. This, says lead author Hansjoerg Kunc, is an animal that doesn’t rely on sound to communicate at all, but still has its form of communication disrupted by noise pollution.

Some of the species perhaps most affected by noise are those that live in a complex concerto with their environment and other individuals around them: the cetaceans. In the coastal waters of British Columbia, new conflicts play out as the ocean pathways traversed for generations by humpback and fin whales and northern resident and Bigg’s (or transient) orcas are increasingly crisscrossed by ships navigating the Kitimat Fjord System. A liquefied natural gas transport and processing facility was approved for the region in 2018, which means that these waters will be busier than ever as tankers move in and out of the channels to deliver the facility’s products.

Recording the voices of the whales of this region helps improve our understanding of their lives, contributing to the picture of the natural history of whales that Janie Wray and her team at the North Coast Cetacean Society (NCCS) are piecing together. However, as the instrumentation of the ocean’s arias becomes busier, the role of scientists is becoming that of the conductor. Scientists are learning to listen to each and every voice and to manage the delicate balance of sound in the sea.

Photo by Fabien Michenet | BiosPhoto

An orca surfaces in parallel with an Alaska Marine Highway ferry in Lynn Canal, Alaska. Our increased reliance on the ocean sees shipping traffic on the rise; its consequences for marine wildlife are now coming to light.
Photo by Design Pics Inc | National Geographic Image Collection

The hydrophone array in northern British Columbia’s Squally Channel, with its four hydrophones placed in their unique rectangular formation on the sea floor, is where Ben Hendricks has been developing the software that will automatically detect, classify, localise and track the vocalisations of ocean animals. On the NCCS website, BCWhales.org, the purpose of this software is succinctly summed up for readers: the information from the hydrophone array can be relayed in real time, with the software notifying its users if a whale has vocalised, when that vocalisation happened, which whale species it was and where the vocalisation took place.

To this effect, Ben and the researchers from the NCCS have spent the past few months piloting a project that will direct the procedure for the team to map how whales are using the habitat in the area and to manage the risk of ship strikes. In the long term, the project will help the researchers to understand the impacts of vessel noise and other human activities on the lives of the whales of the region.

I chat to Ben not long after his return from several months of field work and just after he has submitted a publication to the scientific peer-review system. ‘The biggest boulder that rolled off my shoulders was when we went out on the boat ourselves to test this concept and transmit our own signals. We had a GPS and therefore knew exactly where we were transmitting from. So we learned nothing about the biology of the whales,’ chuckles Ben. ‘Importantly, though, we confirmed that we can indeed acoustically determine the position from where we transmitted that signal. That, for my project, was the first big step.’

The cheerful relief in Ben’s voice is an understated indication of just how exciting this project is becoming. ‘To make this useful to the community – not only for Janie, her team and the NCCS, but for the Gitga’at First Nation that calls this territory home and, eventually, for the management of this region – we needed to show that we can localise everything that whales do. That is, we needed to detect different species, as well as their different behaviours.’

With the success of the first field season and a publication behind them, what exactly does this all mean? ‘There are two layers to this project,’ explains Ben. ‘The first is what this science means for our understanding of the natural history and ecology of whales.’ This is what we explored with Janie: the more comprehensive understanding of how the whales of British Columbia live their lives – the possible ocean pathways of orcas, the timing and location of the humpbacks singing their songs.

‘But, as you can imagine, as we start localising calls and understanding bubble-net feeding vocalisations, different songs and singing features, we can begin to plot these different calls on a map according to where we’re detecting them in the region,’ continues Ben. ‘Each data point lands on the map, so what you end up with is the distribution of different species in the region and what they are doing in different areas. Where do humpback whales bubble-net feed? Where do the fin whales hang out? What are their pathways and patterns?’

Submarine noise and the likelihood of whale strikes increase as ships traverse further, and more frequently, across our seas. This has the capacity to seriously disrupt the ability of many whales to conduct their essential behaviours, like this humpback whale lunge feeding in Paradise Harbor, Antarctica.
Photo by Ralph Lee Hopkins | National Geographic Image Collection

He pauses, then neatly links the natural history element of this project to its conservation imperative: ‘Knowing which whales are in the area, what they are doing and where they are exhibiting various behaviours – that kind of map builds a picture of how whales use the Kitimat Fjord System. We already know how ships use the region. We can therefore superimpose two information layers on this ecological map, identifying where the paths of ships may cross those of whales. This helps us to identify critical areas that may need to remain undisturbed by traffic. It’s what we call spatial planning and to do this best we need to know the habits and routines of both whales and humans in the area.’

The concept of managing increasingly shrinking habitats where humans and the natural world come into contact is perhaps one we’re more familiar with on land, where buildings and roads visibly encroach on the wilderness areas still inhabited by wildlife. Emerging from this need to manage how we balance development with the protection of ecosystems is the field of conservation planning: the art of achieving ‘safe operating spaces’, according to a review paper in the journal Encyclopedia of the Anthropocene.

Conservation planning, for example, contributes to the design of protected areas and involves managing the often conflicting demands of different user-groups. In effect, zones are allocated depending on where animals breed and feed, where they might migrate and what elements of the landscape are critical for their survival. To do this effectively, we need to know how both humans and animals are using the same environment.

This is where piecing together the ecological puzzle of how whales live builds the evidence base that scientists need to advise policy-makers. Where do whales sing, and why? Where do they feed, breed and socialise? How do they move? It is this kind of information that the NCCS and WWF-Canada are working in collaboration with the Gitga’at First Nation to provide. Here, history and context are important: the availability of these data to the Gitga’at First Nation empowers local leaders to make informed decisions about development proposals in their own territory. This kind of transparency and the rapid translation of information is more often than not missing when it comes to projects and policies in regions where traditional communities live in close connection to their environment, but are excluded from voicing their evidence-based decisions about what happens in a region where they have lived for generations.

The songs and sounds of humpback whales form part of complex, and important, social communication, like for this mother and calf near Réunion Island. Recent scientific studies have documented male whales reducing (or outright halting) their songs in response to noise pollution. Author Koki Tsujii from Hokkaido University found that fewer males sang in shipping lanes than elsewhere.
Photo by Sylvain Cordier | BiosPhoto

‘What I’m excited about, because this is something novel that hasn’t yet been done to my knowledge, is having a real-time tracking system for traffic in the Kitimat Fjord System,’ says Ben. ‘Imagine an air traffic control system, where the air traffic controllers monitor who flies where, who is taking off when, who is landing … and all this is managed in such a way that no accident takes place. It’s a similar idea. With the set-up we now have, we can generate these data points – which whales are calling, and where, and where they are heading – and we can do it live. And now we can add ships to this map because most large vessels nowadays have Automatic Identification Systems (AIS) on board, which enables us to track their positions. So you have a real-time map of both ships and whales, and how they are moving in relation to one another, which means that you can react to situations that are potentially threatening to the whales.’

I press Ben a little further, asking about how translatable this system would be to other ocean areas where cetaceans and humans compete for sonic space. ‘Well, now with at least three hydrophones in the water and species that vocalise loudly enough to be detected on the array, you can use the system in all areas. That makes it interesting, but hopefully also puts a bit of pressure on other institutions when it comes to animal welfare. We’ve proven that it’s possible and that it’s a viable addition to what will need to be a suite of tools to manage our noisy oceans.’

The reason that we might be more familiar with the idea of managing people and wildlife – and their increasing contact on the same pathways – on land is not only because we live in this realm and are likely to see the visual evidence from day to day. In the ocean, gathering the kind of information that helps inform conservation planning is logistically challenging and takes a huge investment in time, funding and energy.

Making this kind of science work in the British Columbia region is complicated and tough. Remote and rainy, the Fin Island cabin is home to the Squally Channel hydrophone array project, and to the researchers who doggedly tested the hydrophones and transmissions that helped Ben develop the mathematical algorithms that can automate whale localisations. ‘We spent a lot of our time climbing trees and fixing radio antennas in the rain so that we could ensure the signals from the hydrophones were clearer when they relayed to the research cabin from their position in the water. A lot of fun, but tricky, and certainly not what any of us are best qualified for. Much of the “behind‑the-science” action involved our team getting really good at making a plan, and becoming experts in all kinds of exploits we’d never imagined!’

Ben gives a hearty laugh and I recall one of Janie’s comments: ‘The most heartening thing to come out of this project for me was the phenomenal teamwork and effort from all the people involved.’ For Janie, there was deep satisfaction in working with a team so heavily invested in achieving the project’s goals. Working together with empathy and good communication made the hardships bearable when shuttling equipment too heavy to convey by plane and kept morale high when (as with all science) most initial tests failed, and failed, and failed again…

Photo by Tui De Roy | Minden Pictures | BiosPhoto

Before they head back out into the field, their proof of concept in hand and their algorithms published for the rest of the world to build on so that other researchers and conservation planners – the oceanic conductors, if you will – can integrate this kind of work into their science, I ask Ben what the team has outlined in terms of important development routes for the future of the project. ‘I’m not a biologist, so my field of expertise on this project tends to run through my mind in terms of the data analysis and what would be required here in the future. With this in mind, the first step would be to collect data on any environmental parameters that may be related to the activity and behaviour of whales. For instance, rainfall, temperature and the tidal range could all be collected in concert with the acoustic data we’re using to track whales in the region. Do these affect how whales behave and where they move, and how? If we start to understand this, we can eventually predict what may happen in areas that share similar environmental conditions.

‘Secondly, we’d be interested in ambient noise; that is, if you’re an ecologist listening to whales, everything in the ocean that is not a whale. So we’d like to know how whales handle noisy conditions in their environment. What do they do when there’s a storm? Of course, if we can measure the natural sounds in a whale’s environment, we can also measure the noises related to human activities and begin to understand what impact these have on the whales’ behaviour and movement patterns. Measuring ambient noise would be something we’d like to do in the future, and it can be done using the data we’re already collecting. And of course there is a third, visual aspect to what needs to be done, which is where Janie takes the lead as the expert.’ When funding is difficult to cobble together and the elements test the researchers’ ingenuity and tenacity, the value of the – dare I say, sound – scientific data that can inform how ships and whales share the British Columbia coast is what drives this project.

Back off the coast of Mozambique, I sink into the water for a last dive the following day. The gunmetal sky is indistinguishable from the ocean where it touches the horizon and the world is hushed with the peace that comes with an overcast day. My ears detect the faint crackling of minute creatures suspended in the sea around me, their tiny presence invisible to my eyes, before the muted conversation of the dolphins murmurs into reception. No piccolo voices today: the calves swim sleepily alongside their mothers, their nap-time dutifully observed.

The impact from the occasional hum of an approaching dive vessel pales in comparison with the sonic consequences of the traffic from a proposed port development just north of the Ponta Partial Marine Reserve where I now fin alongside the resting pod. Much like the waters of Kitimat, where a natural gas processing plant has been approved, the waters traversed by the dolphins and humpback whales that sing their way along these subtropical seas are set to thrum with the constant drone of ships on an oceanic highway. I wonder how the submarine symphony I have front row tickets to will change, and what the voices from those communities that live in connection to the coast here might say if we all worked to share information with the kind of collaborative spirit that Janie so appreciated in British Columbia.

Our seas are set to get busier, but as the Fin Island project shows, there is much we can do to better monitor and manage this trajectory. I think of the words of Benjamin Zander, who was the musical director of the Boston Philharmonic Orchestra: ‘The conductor of an orchestra doesn’t make a sound. He depends for his power on his ability to make other people powerful.’ The work of Janie, Ben and their team is a reminder that there is respect inherent in learning to listen, and that the best conservation science gives voice to the kind of information that helps us better navigate how we share a future on this planet.

Photo by Tui De Roy | Minden Pictures | BiosPhoto