Soundbites is a weekly (biweekly, occasionally) feature of the coolest, newest bioacoustics, soundscape, and acoustic research, in bite-size form. Plus other cool stuff having to do with sound. Welcome to November, everyone! Fall is definitely here! I promise I’ll have a proper ASA post up soon, but in the meantime here are your Soundbites for the week!
Cruise ships may be having an impact in developing tourist markets: the good thing about ecotourism is that you’re not openly depleting resources the way you used to be. The bad thing about ecotourism is that increased exposure can degrade the environment. Places like the Eastern Mediterranean and the Adriatic are facing increased noise levels because of increasing tourism.
Microclimate affects frog calls: abiotic noise like streams and waterfalls can have as much of an impact on vocalizing animals as anthropogenic noise. Here the researchers wanted to know if frogs in different microclimates (near stream, far from stream) were changing their call frequency to overcome stream noise, and they were!
Fun link of the weekthis week comes from Holger and Radiolab–the story of a vest that helps deaf people hear.
Oscar Wilde said that “Conversation about the weather is the last refuge of the unimaginative.”
Sorry Oscar, despite my deep respect and admiration to you I will have to object this one.
Talking about the weather is lame; I seriously thought before. But I have changed my mind, since I moved to the Oregon Coast. Talking about the weather is lame at the cases that the weather is consistent, predictable and largely warm and sunny. This is not the case at the Pacific Northwest.
I often find myself complaining about the weather (this is my version of talking about it) since I moved here, and now it’s time to better look into it. Without my usual pout when I curse the rain, or my frown when it’s sunny but really windy. I am not grumpy in reality; I am just a bicycle commuter. That means that I don’t have the choice of a well heated, or at least a dry seat at bike-unfriendly times. I am always exposed to the weather and it affects me every single day. I have been repeatedly soaked by the North Pacific rain and blown away by the Northerly winds (we name the winds from the direction that they come from) over and over again. Immediately when I arrived here I was warned about the horizontal rain that I had never heard of before and no umbrella could keep it off me. The wind is ruthless at the North Pacific.
The truth is that everyone is affected by the weather and has his/her own relationship with it depending on where they come from, what they are used too and how their internal thermostat is tuned, and also on their personality. If you come from Greece, the Oregon Coast will appear cold, whereas if you come from northern France (clear reference to one of my housemates) it will feel like home. If you are outgoing and social the warm sunny weather suits you and defines you. If you are more of an introvert the rain and the low temperatures will provide the right conditions for you to stay home and enjoy solitude.
Research shows that the weather and particularly the sun affect our mood. I clearly see more smiley faces in a sunny day, mine included. Studies indicate a link between low pressure and suicide. On rainy days people report lower satisfaction with their lives. Now imagine how challenging it can be to be a graduate student in a tiny town on the Oregon Coast…!
Overall, I think that the amount of energy that we receive from the huge flaming star on the sky defines who we are, and seems to be a driver of peoples cultures. I am certain that you also have noticed generic cultural differences among people that come from southern and northern regions in a global or even in a national scale. I might be judged for stereotyping but there is some truth to that.
There are 3 major factors why the weather is important for biologists-acousticians:
1. It is linked to food and everyone cares about food
The animals care about the weather! Their distribution is defined by the climate together with other parameters. The sperm whales for example, being truly cosmopolitan, are encountered in the most parts of the world’s seas from the equator to the edge of the polar ice. However they have their temperature preferences. The females like it warm and don’t go to temperatures lower than 15°C. While the groups of females and young males are thought to remain in lower latitudes year round, the macho adult males have wider physiological demands and are encountered in polar areas.
The sperm whales display a remarkable sexual dimorphism with the males being ~1.5 times longer than the females. The larger the size of the animal the more favorable is the surface-to-volume ratio. Even though they have a large surface area that they lose heat from, this area is small in relation to their heat-producing body mass. Thus the males can migrate to high latitudes, especially during summer months, to productive feeding grounds where they karaoke with my hydrophone located at the Gulf of Alaska.
Within their calls I am sure that whales talk about the weather too because highly productive spots are identified, like upwelling areas and other cool places where plenty of food is available and the animals tend to aggregate. Though, the precise process that links the environmental factors in the open ocean with the distribution and abundance of large predators is difficult to be determined and is a major goal of my research. Investigating the oceanographic parameters that affect the movements of sperm whale populations is a particularly complicated matter since they feed on deep sea creatures (bathypelagic squid) and the linkages of physical forcing (wind, temperature) with primary productivity and aggregations of prey and predators are temporally and spatially variable.
2. The sound in the ocean likes it hot
The propagation of sound in the oceans is largely affected by oceanographic variables (which are related to the weather) such as temperature, pressure and salinity. The speed that the sound travels underwater varies from area to area, season to season and different time in the day. Generally the sound speed increases when all the above variables increase. Since these variables change with the depth, the sound speed profile also changes with depth in the water column.
High sound velocity on the sea surface where the water gets warmed up by the sunlight decreases down to the depth where the water temperature becomes constant (~1000m) and then it starts increasing again when the pressure increase is dominant. At the transition point where the sound velocity reaches a minimum (~1000m) it is formed a sound channel where sound waves get trapped and propagate really far away. This is named as the SOFAR (SOund Fixing And Ranging) Channel and some species of whales find it to be very useful to communicate with their friends, partners, parents, cousins and aunts that are immigrants to faraway seas.
I use skype.
Do remember this SOFAR chitchat when you decide to deploy your instrument to record whale voices and you cannot decide on the depth 😉
And to turn the talk-about-the-weather into a hot topic, consider what happens when climate change is introduced and the small talk becomes a conversation where personal ethics, political and social opinions are involved. More like loud talk now! Now that I said loud, did you wonder what is the effect of climate change to the sound propagation and consequently the whales’ communication, and you were afraid to ask?
Ocean acidification, the decrease of the pH in the seas, is a notorious climate change impact. This increase of the ocean acidity changes how sound travels underwater: the lower the pH (more acidic), the ocean absorbs less sound and the higher is the sound speed. And now you are thinking: “Voila, the whales can be heard even further now!”. However, the reality is less comforting (as usually). At the frequencies that the whales vocalize we make a whole lot of noise with shipping and naval activity, seismic exploration and other significant anthropogenic sound sources that interfere with the whales’ skype and consequent communication issues. Yep, ocean acidification makes the sound pollution in the seas into a magnified problem.
3. People love listening to the rain
Since the weather affects the ocean soundscape, then it can also be measured by the sound it makes! Rain and wind generate sound at the sea by producing bubbles during splashing at the ocean surface. These physical processes create different distribution of bubble sizes that have a different footprint on the soundscape. This way the sound from breaking waves (caused by the wind) can be distinguished from the rainfall sound and we are able to monitor the ocean surface conditions from below the surface. Huzzah, here is the solution to trying to measure wind speed and precipitation in difficult locations where the measured vicious weather elements can actually destroy the instruments that we use to measure them. The instrument that I use, the Passive Aquatic Listener (aka PAL) was originally designed by Dr. Jeffrey Nystuen to detect and measure rainfall and wind speed at sea. Lucky me, it works great with recording marine mammals too!
Weather and bubbles talk. This is so scientific.
By this point of this post I have been unnecessarily negative with the Oregon Coast weather which to be frank is what makes this corner of the world into a magical place. The northerly winds in the summer are the reason for the upwelling to take place and all the whales and other astounding marine life to move up this way for food. Seeing the whales from the beach or even just the balcony of your house is certainly worth suffering some cold winds. The world we live in is alive because of the winds. The wind is the breath and the heartbeat of the Earth. The rain on the other hand gives life to thriving and fairytale-like old-growth forests with splendidly diverse and abundant wildlife, fills the rivers and the lakes. Did I mention how outdoorsy I have become?
A question to you: do you also see an irony in the name “Pacific” or I am being grumpy again?
Here it comes, a welcome wind: the wind of change. I am moving to the valley!
Soundbites is a weekly (biweekly, occasionally) feature of the coolest, newest bioacoustics, soundscape, and acoustic research, in bite-size form. Plus other cool stuff having to do with sound. Well, Soundbiters (your new collective noun), term has officially started and the ORCAA students are off and running.
Automated frog call detection–it WORKS!Oh man guys, this is so cool. These researchers developed an automated system for frog identification by call, and it worked even on species they didn’t train the detector on! Talk about huge implications for more efficient monitoring in remote areas!
Cichlids aren’t impacted by boat noise playback: we talk a lot at ORCAA about the negative impacts of anthropogenic noise, so occasionally it’s refreshing to see a species that isn’t impacted in our ever noisier world. Development of this species of cichlid fish was not impacted by playback of boat noise.
Fun link of the week: to be totally honest this has very little to do with sound except that an explosion is involved (just a small explosion, I promise). It’s the first day of October and that means PUMPKINS!! You can make a self-carving pumpkin with calcium carbide and hydrogen peroxide! I would totally try this this Halloween except I’m spending the week prior in Indianapolis for ASA.
“Whistling while you work is only acceptable if you are one of the 7 dwarves. You are too tall to be a dwarf; or the Snow White”, I can imagine Holger, my advisor, saying.
In reality Holger is too wonderful to mind if I whistle while I work or not. But I actually don’t. Which a few unfortunate people that have witnessed it will unanimously agree that it is for the common good. Nevertheless, I get to work on whistles!
The animals that I work with are notorious whistlers! You might consider yourself skillful in whistling, an expert in whistle-flirting and dexterous in folding you tongue and sending loud whistles miles away to your friends on the other side of a soccer field, but that is just like whistling against the wind to dolphins. If you compare your selves to their whistling capabilities you will be embarrassingly defeated. (In every case, several analysts and Experts of Life support that comparing yourself to others can only make you unhappy.)
Dolphins and killer whales, which belong to the Delphinidae family, produce 3 types οf sounds:
1. Clicks used for echolocation that help them navigate, find food and capture it,
2. Burst pulses that are rapid rate clicks and serve similar purpose but with higher definition, and 3. Whistles
Dolphin whistles are generally of narrow bandwidth and frequency modulated sounds that commonly last for half to a few seconds, much longer than the individual clicks and they are of lower frequency. Their characteristic lower frequency allows them to propagate in longer distances and their function is believed to be primarily social.
Whistles are considered to be a product of the same mechanism that generates the clicks: air that goes through the nasal passages of the dolphin’s head. The odontocetes (toothed whales) don’t literally vocalize, since they don’t use vocal cords like we do. They use the air that enters their blowhole to make sound by canalizing it through passages and their melon (the fatty tissue that makes their forehead look rounded). This video: Echolocation and sound production mechanism can give you a good representation of it.The production of whistles seems to require larger volumes of air which makes them unsuitable for echolocation since air volume is reduced by hydrostatic pressure during diving and foraging. Instead, the dolphins are thought to use them for communicative purposes, to stay in touch with their gang in the vast oceans.
I am particularly interested in the whistles. Especially the dolphin whistles. As I described at my previous post, this past summer I collected a bunch of different dolphin species’ acoustic recordings from the Aegean Sea. These recordings will help me create a sound library for the dolphin populations that dwell the eastern Greek Seas, essentially a whistle-bank for the populations in that area.
In addition to the different dialects or accents that the dolphins populations have and I have previously mentioned, they also have names that the scientists call signature whistles. Specifically, the bottlenose dolphins are known to learn and recognize whistles that are unique for every individual in a group and these whistles are used to broadcast the identity and location of the animal that produced them. This characteristic is crucial for the contact between mother and offspring, for feeding and protection from predators. Most of the characteristic whistles are usually unchanged for all the lifetime of the dolphin. But occasionally, when the male dolphins leave their mom to experience the adult life in a group of other males their distinctive whistles actually converge and become very similar!
Besides the dolphins, more animal species seem to find names meaningful. A striking example is the one of the green-rumped parrotlet that lives in Venezuela.
This cute little green parrot is attributed a whistle name by its parents and it gradually learns it by them. In this delightful video you can see how the researcher discovers the learning ability of the parakeets in contrast to the genetic encoding of communication mechanisms in this species.
Birds have actually been the very first research target of bioacousticians. Even though they can fly away and escape the
claws of their scientific fate, it is still easier to study them than the marine mammals that slip away in the open ocean. A remarkable example of unusual bird vocalizations and intriguing to research specie is that one of the superb lyre bird of
South Australia! In this specie the male, in order to attract the girls, besides the elaborated dance and feather display, can also imitate the calls of more than 20 other bird species. This bird is so good at mimicking others that it can confuse even the birds that it is copying.
But the lyrebird is not only imitating other birds; it has evolved his skills beyond living organisms. A real master of mimicry! It is able to incorporate in its repertoire any sound that hears in the forest. Like that of a camera shutter, or a car siren, or chainsaws! Or the sound of the fridge door opening and closing (would be the case if my house was its habitat)…
But seriously, I am not making this up! Check this jaw dropping video to see for yourselves. This bird is either desperate to reproduce or the females don’t really know what they want.
At this point I will paraphrase Snow White; whistling is a lot of work!
Some people seem to have a talent in whistling. They can whistle entire songs, or the more eccentrics can whistle the whole alphabet. They use their lips, teeth and tongue to do it, their fingers in all sorts of strange formations, their palms, and a wide range of imaginative accessories. Personally, it took me several weeks at the age of 23 to learn how to whistle. Soon I was glad for my achievement as it turned out to be a remarkably useful skill when I got a dog. Loud, piercing and sharp… a whistle is hard to ignore. Even if you are a dog.
You might be surprised to discover that whistles are not used uniquely by animals for their communication. Since the Antiquity people used whistles to communicate in very long distances. Whistles can travel much longer than speech and can overcome ambient noise much more effectively. You might have noticed that often people that work in bars use them to signal among them.
In the natural environment, in locations where the landscape consists of deep valleys and steep ravines, whistled languages were common within some human communities. Before the 1940s, when the phone was not widely used yet, people replaced words with whistles to send messages that would overcome distance issues. Whistles have the ability to travel up about to two miles (3.2km), which is much further and with less effort than shouting. Initially these languages were invented and largely used by shepherds, and for long time they were a common way in agricultural communities at isolated villages to transmit news, events or emergencies.
Examples of these communities and their whistled languages still exist! The cases of the Village Antia in the Greek island of Evia, the Kuskoy Village “Bird Village” in Turkey, and the “Silbo” language at La Gomera at the Canary Islands in Spain, are the exceptional cases of alive whistled languages.
In this uncommon language, consonants are distinguished by changes in pitch over different intervals of time and the whistle is a substitute of the original language which gets compressed. The whistled language is not a code, has rather defined characteristics.
Evidently marine scientists are charismatic people with variable interests and acute curiosity . It appears that Cousteau was also interested in analyzing the characteristics of La Gomera’s whistled language!
Nowadays these languages are slowly becoming extinct. However, it is encouraging that in La Gomera at least, the Canary Islands’ government links the whistled language to the identity of the people and recognizes its value as part of the traditional culture in this area and try to preserve it. As a result, La Gomera is one of the few places in the world where children learn to whistle in schools!
Aristotle in the History of Animals wanted to describe what separates animals from people. What is that makes us different: is it the reason, the language or the laughter? Several recent researchers and philosophers suggest that it is the culture. But what do we define as culture. Is it the ability to learn, to mimic, the language? It turns out that both people and dolphins use certain sounds, in this case whistles, in form of language in order to communicate. The human community considers the human whistled language as a cultural heritage worth protecting and maintaining. Similarly, without me trying to attribute human qualities to the animals, cetaceans have social learning skills and cultural capacities that are advanced and worth maintaining as well. It is our doubtless responsibility to protect them.
During my childhood, my mom would wake me up every morning with whistling melodies. I surely despised it. Mainly the wake-up- in-the-morning part. The whistling part was also very disturbing, especially because it was such an effective mean to get me off the bed! Now I am particularly attracted by whistled melodies and I am a fool for songs that include them. So I prepared my favorite Top 10 of songs with whistling, with extra 2 Greek tracks. #1 on the list is my current wake-up-song. I love it! Not the wake-up part, I still cannot get over that…
11. Το ποδηλατο (the bicycle)- Ελένη Βιτάλη
12. Συννεφούλα (the little cloud)- Διονύσης Σαββόπουλος
**Stay tuned in our “vocalizations” through our tweets @ORCAAlab and our facebook updates at Orcaa Lab**
A few weeks ago I wrote to you about my upcoming trip to Glacier Bay National Park and Preserve and my big “Solo” adventure into the great Alaskan Wilderness. Well I’m happy to report the trip was an enormous success and — like so many endeavors in science — all of my “solo” work was accomplished through collaboration.
The purpose of the trip was threefold (1) familiarize myself with Glacier Bay and the surrounding community, (2) identify a viable field site that would enable Leanna and I to meet our dissertation goals, and (3) to build and maintain relationships (with the area and with the people). In short, my goal was all about getting my feet wet in the world of Glacier Bay research, which as it turned out was an extremely easy to accomplish literally and figuratively — Southeast Alaska is very very wet.
The nearest airport to Glacier Bay is in the diminuative village of Gustavus (small town, big character). Living in Juneau off and on for years I’d heard a lot about this tiny place — slow bicycle races and town-wide pancake breakfasts on the Fourth of July, a community garden that would make most Alaskans blush. With a population that ranges from 350-600 (with an influx of seasonal workers in the summer) Gustavus isn’t exactly what you’d call a city, even by Alaskan standards… and it’s not so easy to get there.
I traveled via shuttle from Corvallis to PDX (nothing new here) and hopped a flight to SeaTac Airport where I settled in for a cozy overnight on an airport bench. It felt very familiar. Traveling to and from Southeast Alaska (for less than a small fortune) requires patience, a little bit of traveler’s tenacity, and typically an overnight in Seattle. Sipping an evening tea and looking around the airport I was not the only one with Xtra-Tuffs on bunking down for the night… there were quite a few of us headed home.
A 6-hour layover in Juneau was just enough time for coffee with University of Alaska- Fairbanks PhD student and humpback whale biologist Suzie Teerlink, who filled me in on some of the details of her citizen science initiatives, whale watch cooperative efforts, and some of the in’s and out’s of her Juneau fluke ID project. My first foray into humpback whale research was working with Suzie on some of these projects in their infancy, and was exciting to see how much they’d grown! We wrapped up our reunion with a quick hike before heading over to Wings of Alaska and boarding the 6-seater Cessna 207 turboprop aircraft that would safely transport me over over the mountains and fjords and set me down in Gustavus, AK. There I was warmly greeted by the Park whale biologist (and co-PI on our project) Chris Gabriele.
Over the next few days I had the chance to meet a number of the Park Staff (fisheries biologists, bear biologists, research technicians, administrators and more!), and importantly Chris and I had the opportunity to talk (face-to-face) about humpback whale non-song vocalizations — also called social sounds — produced in Southeast Alaska. Chris and her colleague Lauren Wild of the Sitka Sound Science Center have a new study coming out in the Journal of the Canadian Acoustics Associations on the acoustic properties and usage patterns of the humpback whale “whup” call. The call (which can be heard here), which is a putative contact call, plays a large role in my research past and present. I hope to build off of the work they began at the Park to understand more about how humpback whale use this and other vocalizations, as well as how vessel noise may change vocal behavior (including producing the “whup” call) or limit acoustic communication space. More details on that, and the first chapter of my dissertation, in my next blog post.
Back to the trip, I would be remiss if I led you to believe that we spent all of our time talking (remember goals 1 & 2!). While initially we didn’t think we’d have access to a boat (hence my initial decision to camp on the island for a few days), much to my excitement the Park research boat R/V Capelin came available. My second day in the Park was spent on the water scouting for field sites, measuring bottom depths, marking waypoints for locations of interest, and kayaking through non-motorized waterways to scope out potential field sites. I’m happy to report that we found one! After eliminating what looked to be a lovely cliff (with lots of blind spots and bear scat), and a good hike around Bartlet Cove where the Park’s current hydrophone is deployed (and where vessels transit daily), it was the north east tip of Strawberry Island that made the final cut. It might not look like much in the photos (did I mention that Glacier Bay is part of a rain forest?), but I think it’s exactly the spot we’re looking for.
With a field site decided (Goal 2, check!) one of the last things I was hoping to accomplish on my trip was to familiarize myself with the area, both terrestrial and aquatic. I was fortunate to spend another day on the water with Chris during one of her many whale surveys. It was a great opportunity to view whale behavior in the Park, which I’d anticipated would be different than the behavior I’d observed in Juneau or in Frederick Sound (and qualitatively, it was different); but it also gave me the chance to see more of the Park wildlife (otters! so many otters!) and get a feel for how operations work there. Part of getting familiar with an area involves knowing how to have the least negative impact both ecologically and culturally.
I took a camper orientation which gave me some good tips on how to minimize my impact on the island, but I also spent some time walking through the exhibits and chatting with Park employees, trying to get a feel for both the scientific community at the Park and the rich cultural heritage of the native people in the area. Long before Glacier Bay became a national park it was the ancestral home to the Huna Tlingit people. Near the end of the Little Ice age the glaciers (of which there are MANY) surged forward and the Tlingit were forced to abandon their settlements in the bay and move across Icy Straight to establish a new village. To the Huna Tlingit, Glacier Bay remains their home. In Barlett Cove (where the Park headquarters and the Glacier Bay Lodge are located) the presence of the Tlingit culture is palpable. A Tlingit canoe is on display and current plans are underway for a Tlingit Tribal House.
In what I thought was a poignant manifestation of the culture of science alongside the culture of people, on the same path as the canoe is a structure housing the recently re-articulated skeleton of a humpback whale named Snow, who was struck by a vessel in the Park in 2007. Snow’s bones were buried, cleaned, sent to Maine for articulation and organization, and then finally returned to the Park for the final installation. In a “Alaska’s such a small place” sort of way, one of my first field technicians, Linsday Neilson, was on the articulation team. The skeleton was complete by the time I arrived, but I did manage to catch her for a long overdue hug on the dock.
My last day in the Park I headed out early (5am early) and was fortunate enough to catch a ride on the small cruise ship the Baranof Dream which was headed up-bay toward the glaciers. I spent the day on the boat as a tourist admiring the spectacular scenery and mingling with the passengers. I spent the following two days as the “marine-biologist in residence”, giving talks about our research in the Park, pointing out wildlife, and harkening back to my days as a naturalist in Juneau (the killer whales were certainly a highlight too).
After a few days on the boat, I disembarked in my hometown Juneau, Alaska, exhausted, happy, inspired, a little damp and ready to go home….
But c’mon this is Alaska, you never get out that easy!!! Despite my efforts to leave straight away I ended up with an extra day in Juneau, and while I won’t go into the details of how the extra 36 hours went (that’ll have to be another blog post) you can see from the photo that it turned out pretty well. Until next time!
-Michelle Fournet
***Follow my monthly blog posts here, or check out my personal blog mfournet.wordpress.com for a comprehensive look at my research world***
(A story that follows the adventures of Niki Diogou, the first person that hitchhiked at the Aegean Sea to record dolphin “voices” before somebody else does it)
Since it has been suggested that the idea of leaving the oceans (and then coming down from the trees) was not a wise thing to do, I decided to return to our distant ancestor’s water element for this summer. I spent 2 weeks of late
July and early August at the remnant of the ancient Sea Tethys, where also happens to be my motherland. Tethys Sea, prior to its closure into the Mediterranean Sea, it was the one of the 2 world oceans during the Earth’s early life, when geography class would had been so much simpler (history too) with Pangaea being a unique super-continent. Greece was covered by the
Tethys and nowadays there are fossils at the Aegean islands to prove this intimacy. The Tethys Sea was named by Eduard Suess (don’t get confused, this is a different Dr. Suess ) after the Greek goddess Tethys. She was the daughter of Uranus (Sky) and Gaia (Earth), both sister and wife of Oceanus (there are no taboos if you are a god).
After praying to all the Greek sea gods that I could remember for an opportunity to collect the data I needed for my 3rd thesis chapter, the opportunity arose. Well to be accurate, didn’t really arise itself. I did push it a bit to come up…
The history of every major marine research has passed through 3 recognizable stages, those of: Survival, Enquiry and Sophistication. Otherwise known as the How, Why and Where phases. For instance the first phase is characterized by the question “how can I get funding”. The second, by the question “why do I do this research”, and the third “where in the world is the seawater warmer and clearer”.
To answer the first question I wrote this post.
To answer the second question, I wrote my previous blog.
And for the third ultimate question about the meaning of life, universe and absolutely everything, eeeh I meant the sampling site, the ultimate answer: Greece!
Concerning the second question, I will give you a summary of my field work purpose. Though, Douglas Adams has already expressed the importance of my research:
“Man had always assumed that he was more intelligent than dolphins because he had achieved so much — the wheel, New York, wars and so on — whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man — for precisely the same reasons. The last ever dolphin message was misinterpreted as a surprisingly sophisticated attempt to do a double-backwards-somersault through a hoop whilst whistling the ‘Star Spangled Banner’, but in fact the message was this: So long and thanks for all the fish”.
To avoid this sort of misunderstandings, bio-acousticians have been feverishly working on decoding the dolphins’ vocalizations.
First step towards this direction is telling the voices of different species apart.
Different species of cetaceans are known to produce different types of sounds, resulting from various factors such as morphology, genetics, ecology, sociality, and culture. For example, the calls that sperm whales, humpbacks and common dolphins produce are significantly different from each other in so many ways that are clearly distinguishable by an expert ear (and eye that inspects the spectrograms). This fact makes the lives of the bio-acousticians easier because it helps us to identify different species of whales and dolphins by just listening to them.
Things though are more complicated than this. It has been shown that within the same species, some cetaceans tend to produce different sounds when they live in different areas. So the sperm whales in the Pacific produce codas (a type of vocalization indicative of sociality and communication) that are different to the ones of the Mediterranean sperm whales. Similar is the case for pods of killer whales that use different habitats and target different prey. Likewise, different geographic populations of dolphins that belong in the same species have different call characteristics. It is like speaking dialects or simply having an accent. The differences seem to be greater when the geographical distance increases.
The geographic variations of cetacean sounds are usually divided microgeographically and macrogeographically. For instance the striped dolphins in the Mediterranean Sea produce different whistles than the ones in the Atlantic. Also the striped dolphins that live in the western Med sound differently than the ones that dwell in the eastern side. Applying the same logic, the ones that inhabit the Aegean Sea will have a different “accent” than the Ionian Sea habitants. Past studies have revealed the existence of variations in the whistle acoustic structure of a striped dolphin within the different regions of the Mediterranean Sea. However the Aegean Sea is still an acoustically pristine place. The dolphins we encounter there (common, striped, bottlenose, and risso) have not been acoustically recorded (during visual encounters) and classified. YET!
Being a communicative creature myself, I feel the need of these dolphins in the Aegean to be understood. 🙂
And the same time I will use this information to identify different dolphin species in my N. Aegean acoustic dataset. 😉
I return to the first survival question. If you have read my previous post you will probably remember my public invitation for funding to achieve the acoustic sampling in the area of my interest. In case you are not fortunate enough to study and work on the field with the charismatic megafauna, I should enlighten you into the specific requirements of cetacean research: HIGH BUDGET! Cetacean research is particularly expensive. Money for renting a boat, gas money for the boat, money for the boat crew (a captain at least is required) and money for the acoustic instrumentation.
Because the times are hard and funding appears dimly or not at all in the horizon, I had to recruit some old skills of mine to make this happen. Hitchhiking skills (contacts also help, so get your selves out to these conferences)!
I first thumbed a ride when I was doing my undergraduate at the island of Lesvos, in Greece. With my friends we would hitchhike to the university which was slightly further from downtown. Too far to walk when you are already late for the morning lecture, too close to wait for the bus that has a very irregular schedule, too expensive for taxi while being a student, and just the right distance to be given a lift! That is when my hitchhiker’s career commenced. Now that I have reached a Ph.D level and I only possess a bicycle, my hitchhiking skills have equally improved and can be utilized for science. In this case, the thumb got replaced by emails, phone calls and meetings.
Not too far from the area that I have my hydrophone deployed and I get part of my acoustic data; there is the island of Alonissos. T
here, it is founded the first Marine Protected Area in Greece that happens also to be the biggest in Europe. The marine area around Alonissos Island, together with 6 more islands, 22 islets and rocky outcrops is one of the few remaining habitats of the Mediterranean monk seal; the only seal specie in Med. In the past, the monk seal was very common all along the Mediterranean coasts.
Nowadays, it is on e of the world’s most endangered marine mammals and
half of its current population lives in Greece. For this reason in 1992, the National Marine Park of Alonissos, Northern Sporades was established and is dedicated to the protection of this rare species. There are laws a
nd regulations that limit certain anthropogenic activities that could interfere with the animals’ welfare and the population’s survival. To impose these regulations and ensure the good management of the reserve, the guards of the Marine Park patrol daily the marine protected area. And this is where my thumb comes up. The lovely people that work for the Marine Park accepted me on their daily patrols, allowed me to get on their boat and look for dolphins while they were looking for any illegal activity.
So I bought a big hat, I got my dipping hydrophone, swimming suit as my uniform and my Dolphin Quest began!
First day on the boat was mind blowing! Traveling with 35 miles/hour, stop every now and then to exotic locations, blue caves, a long break to rest the engine and the guards, have some drinks and swim in turquoise water coves. Marvelous sites that few have had the chance to visit.
And you will rightfully ask: did you find the dolphins?
No. But it was a good way to break the ice!
The following days were much more effective. I explained that for the purposes of my research we would have to go slower. As a hitchhiker I hesitated to reinforce my own rules to my hosts but soon our zodiac was going with 15 miles/hour and had 2 extra visual observers on board scanning the horizon for dorsal fins and splashes.
Still though, no dolphins in sight.
You see, the ocean is big. You just won’t believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to ocean. Searching for dolphins there is not an easy job. It is fun but not easy. It can take unpredictable amount of time until you get to see them. And I had only a few days before my flight back to USA…
Fortunately dolphins are curious creatures and if the boat is not too noisy they will swing by for a bit to check it out and hopefully play with its wake. Just like this. Eeeeeh, I wish.
A couple of days went by without any dolphin luck. And the thump comes out again for extra rides. I needed more time in the sea.
and Protection of the Monk seal who has been monitoring the monk seal population and promoting the establishment of a Marine Park for almost the last 30 years also operates in the same area. The last 2 years Mom has been running the Northern Aegean Dolphin Project . A team of volunteers and their lovely project leader, also called Niki, perform daily visual transect surveys to study the population and ecology of the dolphins in the Marine Park region. I
hitched a ride with them too. Success from our very first cruise! A monk
seal sighting first thing in the morning and a big group of striped dolphins that we were able to stalk for a while. Stalk and eavesdrop on their conversations! This raised my expectations.
My days passed with me jumping from the one vessel to the other exploring extensively the N. Aegean Sea. But without enough dolphin sightings. And while I was trying to compromise with the idea of having only striped dolphins’ recordings and thinking of the shift I would give to my research, disappointingly looking for any dolphins, the common dolphins appeared and gave me hope again! Fortunately, trustworthy hope. Later on the same day a mixed group of common and bottlenose dolphins was having a long dinner close to our boat. After recording them for long time, I did not resist jumping in to the water. There were far enough to not be interrupted by my presence but close enough to hear them while I had my head underwater. I was shaking with excitement. Dream comes true. Check.
My field trip ended with recordings from 3 different dolphin species, 2 monk seal encounters, countless seabirds, and 3 illegal spear-gun divers. The sea CSI in action!
The only problem was that I had to go. Too soon I think. But would there ever be a right time to leave this heavenly place?
And now I am back in Newport, my skin has still some tan left and all the Greek memories are still fresh with strong salty flavor. My suggestion is the following:
Do you want to implement research but you don’t have funds to do it? DON’T PANIC. There are ways and alternatives. Consider the hitchhiking method. It is an inexpensive way to do your sampling and it essentially means collaborating, meeting people, working together, sharing and having a common direction. I assure you, it’s the journey not the destination that matters.
My gratitude to the National Marine Park of Northern Sporades and MOm, the Northern Aegean Dolphin Project, for their hospitality and help. Definitely worth a visit and I am already craving my return!
Soundbites is a (hopefully) weekly feature of the coolest, newest bioacoustics, soundscape, and acoustic research, in bite-size form. Plus other cool stuff having to do with sound.
It was a slow news week, folks, so I went back in time a bit to get you some interesting tidbits.
Tree crickets not affected by anthropogenic noise: in a field where we’re constantly searching for an effect, sometimes it’s nice to read a paper that says the opposite. The authors speculate that because tree crickets evolved to call in environments with lots of other calling insects, they might not have issues with high anthropogenic noise levels.
White-throated sparrows alter songs differentially depending on noise source: depending on what noise is going on in the background (cars, spring peepers, wind, or other birds), white-throated sparrows would change their songs to compensate in the way that would allow them to be best heard. Sometimes this was singing at higher frequencies, sometimes it was not singing at all. It just goes to show that you can’t look for a single, across-the-board response to noise.
Fun link of the week: kind of a rough cut on this, but it’s from the source so I’ll stick with it. David Rothenberg is a musician and a philosopher who does live duets with animals. Here he’s playing with some humpback whales in Hawaii. I first heard about this guy on Radiolab and he’s super cool. So is Radiolab.
And the living is not necessarily easy but certainly more easily entertaining. Besides the wedding season it’s also conference season. All the lab-mates travel on the other edge of the country (USA) for summer schools, meetings, exciting field trips and pilot classes (stay tuned and Selene has some stories to tell). I made it to the other end of the Atlantic and all the way to my beloved motherland. My first time participating at the Underwater Acoustics meeting, an international conference that took place at the Island of Rhodes in Greece, just a few days after the meeting of the Acoustical Society of America that took place at Rhode Island in USA. Appears that the islands of roses (Rhodes derives from the Greek: rhodo which means rose) were acoustically active this summer. Coincidences are fun.
Four exciting projects were presented by OSU people.
Haru Matsumoto, had a presentation with the imaginative title: “Antarctic’s Siren Call: The Sound of Icebergs”. I absolutely love it when people use a cool title for their scientific projects! His talk and his project was as exciting as it sounds and it was by far my personal favorite non-bioacoustics talk of the conference. Haru showed how the sound of melting icebergs affects the noise budgets in the South Pacific Ocean. The disintegration of two large icebergs at Antarctica produced low frequency sounds, so loud that they propagated and got recorded across the equator up to 8o N, 10.000 km away from the icebergs! He measured an increase of the noise level by 6 dB and 3 dB in comparison to baseline years (when the melting icebergs were absent). If 3 and 6 dB doesn’t sound like a significant increase to you then you are probably not aware of the decibel scale. This Radiolab podcast “The Walls of Jericho” will entertain you and will explain in a simple and funny way how this scale works.
Lately we have been seriously concerned about the shipping, airguns, naval sonars and other prominent man-made noise in the ocean and how they interfere with marine life. Haru’s presentation opened a window to think how a non-anthropogenic sound source can have such an impact to the marine soundscape, and potentially impact specifically the largest baleen whales (blue and fin whales) that also vocalize at low frequencies (below 100 Hz). Even though natural, the melting of the icebergs can be effected by anthropogenic activities, in particular the human induced climate variability and global warming. No need to be more specific, feel free to consider further potential ecological implications.
Bob Dziak presented, through Haru (unfortunately Bob was not able to make the Oregon-Greece 20 hours long travel), the “Sources of long-term ambient ocean sound near the Antarctic Peninsula”. Bob’s project was one step more general and inclusive. He described the contribution of a variety of sound sources to the soundscape of the frozen South. Acoustic data were collected during 4 years using 2 hydrophone arrays and the results indicate that the main factors of sound production or “noise” (depending from which point of you look at it: the biologist’s or the geophysicist’s) around the Antarctic Peninsula are the icequakes (acoustic signal derived from fracturing of large free-floating icebergs or ocean front icesheets) and the whale calls!
The weather conditions are too rough for sound-measurable human activities and both the blue and fin whales seem to take advantage of this human-almost-absent corner of the world. The sound of the ice breakup and grounding is clearly the most prominent sound source in the Southern Ocean Basin but it varies seasonally. Bob’s presentation (same as Haru’s) made me switch my perception of summer and winter for a bit. In Antarctica, during the austral summer the increased temperatures result increased icequakes and the release of acoustic energy. The opposite happens during the austral winter when the icesheets form, even though the wind speed increases. The giants of the Antarctic Peninsula seem to follow the freeze-thaw cycles and their peak season matches the sea-ice-cover-minimum of the austral summer. Consequently if you want to see fin and blue whales when in the North Hemisphere is still winter, chase the summer down as south as it gets…
This conference was an excellent opportunity to reunite with ORCAA’s favorite Naysa. It had been almost a year since Naysa left Newport, after her few-months stay and collaboration with the CIMRS, and it was an indescribable pleasure to spend some warm Greek time with her and watch her awesome presentation on “Acoustics as a tool to reveal population structure of the elusive blue whale”. Naysa talked about the smallest subspecies of the largest animal on earth. The pygmy blue whale. She used 5 sites in the SE Indian and the SW Pacific Oceans to collect 3 years of acoustic data to
determine the occurrence of pygmy blue whale in these locations. Apparently th
is species produces 5 regionally-specific calls: the Madagascan, Sri Lankan, Australian, New Zealand and Solomon type. Naysa used an automated method (detector) and was able to detect the “Australian” and the “New Zealand” dialects at the SE Indian and the SW Pacific Oceans respectively and her results provide evidence of a previously unknown population, the latter one! Naysa’s study is an excellent example of the numerous applications of acoustics, particularly to the population and movement patterns of marine mammal species over large spatial and temporal scales. The more I enter into the acoustics field the more excited I get about the knowledge and information that the sound solely can reveal us, especially about elusive cetaceans, like Naysa’s pygmy giant.
In the Ocean it is a common truth that what the eyes cannot see the ears can hear!
After seeing Naysa’s presentation I have one technical advice for presenters. Go simple or go home! She managed with minimum text, probably no text at all, pretty slides with most of the times just one picture, to get across her messages and keep the attention of her audience! Focus on the gist of your talk and feel confident to leave the details out giving the opportunity to people to ask for them if needed.
For my presentation we move back to the North Hemisphere and head eastwards. I presented my work at the Greek seas with the title: “Passive acoustic detections of odontocetes in the Ionian and Aegean Seas, Greece”. Even though cetology was born in Greece (as mentioned in my first post: The philosophy of sound) 2500 years ago, little research has been done in the Greek seas since then. Mainly the Ionian Sea (west of continental Greece) has been investigated and almost exclusively during the warm summer season, while the cetacean populations in the Aegean (east of continental Greece) are largely unknown. I used 2 hydrophones during 19 and 10 months to assess the seasonal occurrence of different species in these two regions and determined the seasonality of especially the sperm whales (that I particularly love, usually dream of, and I am overall obsessed with) and the delphinids. I am proud to have performed the first long-term bio-acoustic monitoring study in Greece and looking forward to going out to the clear blue Greek waters to collect ground truth data necessary that will allow us for first time to tell apart the different dolphin species that dwell the Aegean! Any funding suggestions anyone…? If you do, you are welcome to join me at an Aegean cruise chasing dolphins!
My presentation was a poster and even though I am usually not very fond of this form of communicating my work, there is no way that I could have had a better result/impact and feedback. While I was thinking that 3h of a poster session would be dull and endless, I ended up spending more than 5h chatting about gender determination, localization of my animals with one single hydrophone (!), acquiring more acoustic data, using my spectral information for species detection, and getting inspiration from wonderful colleagues coming from Italy, Australia, China, Israel, San Diego, Boston, Pennsylvania and around the globe.
Poster take home message: if the number of posters is low (<10), dare to submit one, especially if the number of parallel oral presentations is high (>=3).
This has been a wonderful and productive meeting! 5 days of underwater acoustics bliss. Listening and talking about the sound in polar areas (always fascinating environments), about bubbles (it might not be as etheric as it sounds but still interesting), oil and gas, renewable energy, hydrophone calibration, soundscapes, ships and noise, sonars, super-cool technologies that make me want to be an engineer, a bunch of marine sound-related stuff and of course whaaaaaaaaaales! Besides the days, the nights were equally exhilarating but in a more social way.
I met people from all around the world with whom I shared scientific ideas, PhD and work related concerns, personal perspectives and liters of raki 😉 It is always good to combine work and fun. Even better when work is fun. That is certainly true for my case and I bet for my ORCAA mates too. Lucky people!
See you all again at the next Underwater Acoustics meeting in Greece.
Next blog-post will include some of the Greek summer sunlight, the salty flavor of the Mediterranean and the sound of cicadas.
You may find this difficult to believe, but now that I’ve reviewed an entire year’s worth of data from Alaska’s Beaufort Sea I can say with great confidence (and no scientific evidence) that Marvin the Martian was in fact a bearded seal. If you don’t believe me I encourage you to listen to this sound and tell me that when he’s hanging out in his PJ’s on Mars that this isn’t exactly what’s coming out of our little Martian friend’s mouth.
While of course I’m being facetious, it is only to a point. The scary alien sound effects that have been ingrained in pop culture are made manifest in the Arctic soundscape. While the stoic images of starkly white sea ice may elicit feelings of cold noiselessness, underneath that sea ice it is loud.
In collaboration with the NOAA/PMEL a calibrated autonomous underwater hydrophone package (AUH) was deployed at the continental shelf break approximately 50 miles off the of the coast of Alaska in the Beaufort Sea. Using the AUH we were able to record continuously for an entire year (as my lab mate Amanda tweeted once she was done analyzing beluga calls “I’ve officially finished analyzing 8,760 hours of Arctic#bioacoustics data”). For the acoustic buffs out there, the AUH was able to precisely record underwater ambient sound levels with 16 bits resolution (i.e., with 96 dB dynamic range) in the 10 Hz to 2,500 Hz frequency range. For the non-acoustics buffs out there this means that we could record sounds ranging from just below the low end of human hearing to about the pitch of a high whistle (think a little girl whistling Andy Griffith).
This was my first foray into Arctic acoustics, and I was properly daunted. My experience to this point has been strictly working on acoustics collected in Southeast Alaska that had concomitant visual observations. There were only three species my hydrophones were likely to detect- humpback whales, killer whales, and harbor seals. In the Arctic, however, there are many species (we detected bowhead whales, killer whales, humpback whales, beluga whales, ribbon seals, ringed seals, AND bearded seals). Furthermore the sound of the ice itself is deafening! It whistles, whines, creaks, groans, and pops- making this critical abiotic feature a character in its own right.
The Arctic is known to be visually “other-worldly” and I cannot emphasize enough how this is made manifest acoustically. For the spectrogram savvy this is a spectrogram of Marvin the Martia… I mean two bearded seals. FYI- this spectrogram was generated from the afore referenced sound file. For those less familiar with a spectrogram, a spectrogram is a visual representation of sound. Time is along the x-axis, and frequency (which we related to pitch) along the y-axis. The colors represent energy (or as we manifest, volume). The brighter the color the louder the sound. By generating spectrograms it allows researchers (like the PI’s, technicians, and of course grad students) here at ORCAA to classify caller species, to classify call types, and to gain a better understanding of who is utilizing the marine habitat and when. In the case of this Arctic data set I enlisted the advice of Arctic expert Kate Stafford at the University of Washington Applied Physics Lab to help me classify some of the more obscure files. She generously pointed me toward an excellent new publication which enabled me to compare the spectrograms that I was generating with those from known species.
Despite the many resources (publications, lab mates, experts in the field) I was still unable to identify all of the calls to species. Many calls were graded, others obscured by the sound of airguns (possibly more on the topic of airguns in the future), and still others vocalizations obscured by the sound of ice. Given that the goal of the project is to monitor long-term changes and trends in the Arctic underwater ambient sound field I understand that this is a cursory first pass at an incredibly rich data set. With as many hours as have yet to make their way into our lab I can’t help but imagine… who other than Marvin we might find there.