Interested in sound in the ocean, but confused about where to start? Do your eyes glaze over when you read about decibels, kilohertz & logarithmic scales?
YOU’RE IN LUCK!
Here are a couple of reports that we found to be gentle introductions to the physics of sound in the ocean. One is a great booklet written for the US Marine Mammal Commission. The other is an acoustics pocketbook by our colleague, Dr Christine Erbe. Hope you find them as helpful as we did. Be sure to check out our latest acoustics work here.
During a seemingly ordinary fall day with dolphins, I captured killer whales attacking and eating a dolphin on film. It inspired me to devote a chapter of my PhD to killer whale predation on dolphins and the incredibly dynamic interaction unfolding between an intelligent, efficient predator and its similarly intelligent prey. I’m hooked. There is so much to learn about this process. Our colleagues have written very cool papers describing how mammal-eating killer whales attack and kill their prey: here’s one and here’s another. And someone has just posted another cool video of dolphins and killer whales off Hyacinthe Island. We’ve been trying to track down whoever shot that video so we can compare notes. If you know who they are, could you please put us in touch? Thanks!
The Pacific white-sided dolphins we study are engaged in a daily struggle between finding food and avoiding being eaten. Some days are better than others. If you look in any field guide to marine mammals, you’ll find that Pacific white-sided dolphins are supposed to be an offshore, open-ocean species. We think these dolphins are here, in the inshore waters of British Columbia off northeastern Vancouver Island, in part to take advantage of fairly reliable food sources like herring and other small, schooling fish. We also think that chasing fish in these parts carries a serious risk. Death. This area is known for reliably seeing resident, salmon-eating killer whales, but the inlets that the dolphins use are also prime hunting spots for mammal-eating, transient or Bigg’s killer whales.
A lot of the work we do is to understand the choices that these dolphins make between finding food and avoiding predators. While dolphins may not avoid predation altogether, they might have some behaviors up their sleeves that allow them to survive in habitat where predators could be around every corner. Maybe they cut their foraging a bit short here and there, or keep quiet to elude detection by the killer whales highly-evolved sensory systems. But smart as dolphins are, they’re not going to 100% effective at avoiding predators. And hey: killer whales (OK, you know that killer whales are the biggest member of the dolphin family, right?) have to eat, too.
Today, we saw the best answer possible to that question, in E.O. Wilson’s amazing TED talk, called “Advice to Young Scientists”. We’ll wait while you watch it.
Wilson outlines the lessons learned from his career in interdisciplinary science as a series of basic principles, but the most important one is this:
Don’t worry if you love biology but are afraid of math.
You can learn math the way you learn any other language. You can earn excellence in your field, whatever your level of statistical expertise. And you can always find statisticians to collaborate with.
Which is the answer to our Scottish-Canadian mismatch question. Yes, our whales are in Canada, but some of the world’s best statisticians who work on conservation biology work at the University of St Andrews. We’re extraordinarily lucky to work with them, and extraordinarily grateful that these statisticians are interested in the biology we do. And when these statisticians offered to help us spend 2 years improving the science we do, so we can better protect the whales and dolphins we study, we leapt at the chance.
The Pacific Northwest is special too. We could do field work or analysis anywhere, but it’s only in British Columbia where our field work is integrated seamlessly into our everyday lives. We’re looking forward to getting back to the field briefly next month, and on a more permanent basis when we move back home in December.
Wilson also outlined a principle about choosing ideal study animals and research questions. He believes that for every problem in science, there is a species ideally suited to study that problem. Conversely, for every species you study, there is an important scientific problem for which that species offers an opportunity to develop a solution.
Our primary study animals (killer whales & Pacific white-sided dolphins) represent a great span from data-rich to data-sparse systems, and the other species we study (e.g., fin & humpback whales, sharks & mola mola) are intermediate points along that spectrum. With resident killer whales, we’re constantly running into the need to do analyses that take into account how much is known about these animals. It becomes a challenge to make our studies sufficiently generic that they can be applied to other populations of whales around the world. Pacific white-sided dolphins, on the other hand, represent much more of a blank canvas. All of the research that we do on them feels pioneering. Discoveries hide around every corner. Just getting enough data points to fit a simple statistical model can be a challenge. But this tension — between well studied and poorly studied animals, or between rare or abundant populations — is the fascinating and exciting part of our work. It’s our passion.
But passion takes work too. We think that Julia Child said it best:
“Find something you’re passionate about and keep tremendously interested in it.”
That last bit — keep interested — is the key. In any field of science (or when perfecting your boeuf bourguignon recipe), the novelty wears off quickly. You have to sustain it, and that’s hard work. It can also be expensive work. Science, like fashion, has its trends, and it can be tempting to follow those trends. Funders and scientific journal editors like it when you follow those trends by placing your research questions in the context of the latest hot topic. It can help you build a solid and safe career. But there is something inordinately satisfying about creating your own trend. We start every project by finding out what’s already being done by our colleagues, and we try to explore new territory. Because we find funding for every project we do, and because the animals we study face so many competing conservation threats, it is important to us that we not reinvent the wheel. We deliberately seek out the margins, and that can feel a bit uncomfortable at times. We were thrilled to hear Professor Wilson address this in his TED talk: in the military, there is a famous saying that soldiers should follow the sound of the guns. In science, Wilson encourages us to move in the opposite direction of the guns. He says,
It rains a lot in the rainforest. Even when the rain lets up, photographing grey dolphins swimming through grey water under a grey sky has its challenges. Our camera is often pushed to its limits. Out in the snow, rain, mist or fog falls in our little open boat, we dream of sunnier habitat. They do have dolphins in Mexico, after all. But, the dolphins we study here in British Columbia, Pacific white-sided dolphins, have decided this is home. And, while it’s true, they do have closely-related cousins in Mexico, we suspect these dolphins are homebodies.
We’re glad they like it here. Although we travel a lot for work, we’re homebodies too. The thousands of photos we take are helping us figure out where these dolphins call home. With each photograph of each individual dolphin, we have a data point that can help us tell the dolphins’ stories. The more times we capture an individual on film, the more times it enters our catalogue, and skipping over some math, that tells us how well the dolphin population is doing. Do they need protection or is the population doing just fine without our help? It also gives us clues about dolphin movement and whether they remain inshore or go exploring in pelagic waters.
Thanks to the generous support of contributors to the Beyond Miles Aeroplan Program, all the wonderful supporters from our Dolphinpalooza fundraising campaign, and a lot of friends at home, we are conducting another field season this August. We’re pretty anxious to get home, and see what’s changed since the last time we saw the dolphins.
Oceans Initiative is a team of scientists on a mission to protect whales, dolphins and their habitat. To celebrate World Oceans Day, we’re releasing the main findings from our Ocean Noise project. Our clever friends at Column Five Media have helped us turn our cutting-edge acoustics research with Cornell University’s Bioacoustics Research Program into a simple, visual story. Please feel free to download the infographic, or share our page with your friends.
But whale habitat is more than physical space and food to eat.
“The places in which these animals live are defined not only in terms of space, but in terms of sound – they live in an acoustic world and depend on that world for survival,” says Dr. Christopher Clark from the Cornell Lab’s Bioacoustics Research Program, who has been listening in on the whales to get a better understanding of how noise impacts their acoustic habitat. “Imagine living in a village where you can’t see each other or where you’re going. Instead, everyone relies on sounds and calls to go about your lives and to maintain the social network. What happens to your world as the smog of noise gets to the point where you cannot hear each other?”
We love partnering with smart, talented people to multiply our impact. In 2008, we partnered with Dr Christopher Clark and Dimitri Ponirakis at Cornell University’s Bioacoustics Research Program to find out how ocean noise levels in British Columbia measure up to the rest of the world. We wanted to find out whether the whales in BC have a relatively quiet ocean or if ocean noise levels are high enough to challenge the whales’ ability to hear each other and find food.
With the help of a few visionary funders and a very long list of generous friends (THANK YOU!) who helped us in the field, we used Cornell’s cutting-edge hardware (specialized underwater microphones) to record shipping noise and whale calls in strategic sites along the BC coast in 2008, 2008 & 2010. The hydrophone recorders sit on the seabed for weeks or months, recording all ocean sounds (human and natural), then we navigate back to where the hydrophones were dropped, play a signal to them and the device pops up to the surface with a record of everything it heard during the deployment.
Once we retrieve the hydrophones, Dimitri Ponirakis works his magic in the Cornell lab, and turns thousands of hours of recordings, terabytes of data, into some results that we can use to quantify how noisy or quiet whale habitats are. We then asked the visionary team at Column 5 Media to help turn our decibels and decimals into a delightfully appealing infographic that communicates our results.
The Secret to a Sound Ocean infographic shows typical noise levels in three frequency bands. Think of it this way: the three bands represent what the noise levels may sound like to a killer whale (a soprano), a humpback whale (a tenor) and a fin whale (a bass). What we’re finding is that some of the most important areas for killer whales (e.g., Robson Bight & Haro Strait) happen to be among the noisiest sites we sampled. And some of the areas that are most important for humpback whales are fairly quiet (Caamano Sound, Kitkiata Inlet), but could get a lot noisier given the number of industrial developments planned for the area. Our data for this important area are unique, and we are glad that our funders helped us collect essential baseline recordings while the area is still relatively quiet.
Our plans for this work is to put this all into a framework that allows us to answer the So What? question. We’re able to model how much acoustic habitat these different whale species lose in sites with different noise levels. Rob’s Fulbright Chair position explored the ocean noise issue from a policy perspective. Now his Marie Curie fellowship at the University of St Andrews allows him to build mathematical models to explore how chronic ocean noise could affect the dynamics of fin, humpback and killer whale populations.
The thing we love most about this issue is that it is a relatively solvable problem that lends itself to creative solutions to make life quieter for marine wildlife. Our current work identifies whether we can reduce noise levels by asking ships to slow down or avoid certain areas altogether. We’re identifying whether some areas are so quiet that they should be recognized as national treasures: acoustic refuges that we try to manage so they stay quiet. Our mission is to identify noisy areas and to help make them quieter; and to identify quiet areas and to try to keep them quiet.
If you’d like to help our efforts do that, please spread the word. Please share this page, subscribe to our newsletter, or follow us on Facebook, Twitter, Pinterest or our Aeroplan Beyond Miles donation page. Thanks again to everyone who has helped us do this work, and Happy World Oceans Day!!!!!
