Author: Miranda Mayhall

Imogen Lucciano, Graduate student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab. 

Work in the GEMM lab is booming in all different directions of whale research, and so taking turns writing for the GEMM lab blog gives all of its members an opportunity to highlight topics that are specific and current to us individually. I am two-thirds of the way done with my MSc thesis program, and I’ve recently begun speaking publicly about my work on the HALO project and fin whale acoustic detection off the Oregon coast. In this blog I’ll highlight a two-part question that I am often asked, “Can you see more than fin whales in the data, and how can you tell the species apart when you are looking at it?”. These questions provide great ponderance and are very significant to what I am trying to accomplish. The answer is that I absolutely can see other whales when I am looking through the acoustic data and in fact I have to be quite meticulous in my efforts to tease them apart at times. Let me explain:

The acoustic data set I am working with tells an important story of the waters off the Oregon coast and will illuminate researchers (and the public) on the presence of all detectable vocal whales and dolphins in the area over the past year, from October 2021 to January of 2023. The advanced technological recording systems, called Rockhoppers, that HALO deploys off the coast of Newport, provide us with continuous sound files for the entire time that they are deployed. (I previously wrote a short blog on Rockhoppers, for those interested in more information.) Then, we analysts (graduate students) on the project work to establish the acoustic presence of our target species within those files.

Based on what experts in the field of cetacean bioacoustics currently understand about fin whales, they produce sounds at a very low frequency for both socializing (presumably their 20 Hz pulse call) and for foraging (presumably their 40 Hz downsweep call) (Sirovic et al. 2013; Romagosa et al. 2021). During my efforts to determine the presence of fin whales, it is relatively easy to identify the 20 Hz pulse call, since this call has been well documented in the literature and is the only cetacean call described that occurs in its frequency range. I look for these calls in spectrogram representations of the acoustic data, which allow me to see the selected frequency range over our data collection period (time; Figure 1).

Where this process becomes complicated for me is when I look for the 40 Hz fin whale downsweep call, which is known to occur between ~ 75 Hz – 30 Hz (Wiggins & Hildebrand 2020; Romagosa et al. 2021). This call can vary slightly within this frequency range. Interpretation of this call reaches even higher ambiguity when there are blue whales and sei whales acoustically detected in the same time frame in the same area. The acoustic repertoire of both blue and sei whale calls fall in the same frequency range: blue whales producing what is known as “D calls” and sei whales are known to make low-frequency downsweep calls (Figure 2; Sirovic et al. 2013; Romagosa et al. 2020).

At first glance, the vocalizations from these three whales can be easily confused, and so I am looking for finer details to help tease out the fin whale downsweeps. As shown in Figure 2, there is a difference in the behavior of these calls, with the sei whale call being a shorter call by a matter of 2-3 seconds. The sei whale downsweep calls have not been frequently described in the literature, however those few publications report these calls occurring over 1.4-1.6 seconds (Baumgartner et al. 2008; Espanol-Jimenez et al. 2019) and in each published spectrogram, I have observed this similar boomerang-type looking behavior in the call. Blue whale D calls, on the other hand, are calls produced as social calls while foraging (Szesciorka et al 2020) and known to occur over ~1.8 seconds (Oleson et al. 2007).  

Fin whale 40 Hz calls have a duration of about one second and are not known to be produced in a regular sequence (Sirovic et al. 2013), thus I am teasing them out carefully from what can sometimes appear like a diversly grouped choir of low frequency whale song among the HALO data (Figures 3 & 4).  

Although there are some known seasonal patterns of each of these aforementioned whale calls (Sirovic et al. 2013; Szesciorka et al. 2020), many data gaps remain of the temporal patterns of the 40 Hz and 20 Hz calls (i.e., when the calls occur) off the Oregon coast. Therefore, I cannot assume that I will only see 40 Hz calls in any time period. I need to assess the behavior of the calls I detect and tease out the calls I know surely are fin whale 40 Hz downsweeps in each file of the entire acoustic dataset.

Afterthought: The HALO project is new and has only just collected its first year of acoustic data, however the project is intent to continue deploying and collecting Rockhoppers off the Oregon coast for years to come. As this acoustic data set continues to grow it will be used by other researchers, and I (among the first to process and analyze it) feel some pressure to get things done right. As I process these data I will work hard to make the best-informed call identifying fin whales in the 40 Hz range. This focus and feeling of responsibility reassure me that I am in the appropriate career field. I really care about how these data are processed, where the research will go from here, and how it influences human activities in this critical whale habitat.

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References

Baumgartner, M., Van Parijs, S., Wenzel, F., et al. 2008. Low frequency vocalizations attributed to sei whales. Acoustical Society of America, 124 (2): 1339-1349. https://www.whoi.edu/cms/files/JAS001339_59390.pdf.

Espanol-Jimenez, S., Bahamonde, P., Chiang, G., Haussermann, V. 2019. Discovering sounds in

Oleson, E., Calambokidis, J., Burgess, W,. et al. 2007. Behavioral context of call production by eastern North Pacific blue whales. Marine Ecology Progress Series, 330 : 269-284. https://www.int-res.com/articles/meps_oa/m330p269.pdf.

Romagosa, M., Baumgartner, M., Cascao, I., et al. 2020. Baleen whale acoustic presence and behavior at a Mid-Atlantic migratory habitat, the Azores Archipelago. Scientific Reports, 10. https://www.researchgate.net/publication/339952595_Baleen_whale_acoustic_presence_and_behaviour_at_a_Mid-Atlantic_migratory_habitat_the_Azores_Archipelago.

Romagosa, M., Perez-Jorge, S., Cascao, I., et al. 2021. Food talk: 40-Hz fin whale calls are associate with prey biomass. Proceedings of the Royal Society B: Biological Sciences, 288 (1954): 20211156. https://pubmed.ncbi.nlm.nih.gov/34229495/.

Sirovic, A., Williams, L., Kerosky, S., Wiggins, S., Hildebrand, J. 2013. Temporal separation of two fin whale call types across the eastern North Pacific. Marine Biology, 160: 47-57.

Szesciorka, A., Ballance, L., Sirovic, A., et al. 2020. Timing is everything: drivers of interannual variability in blue whale migration. Scientific Reports, 10 (7710). https://www.nature.com/articles/s41598-020-64855-y. Wiggins, S. & Hildebrand, J. 2020. Fin whale 40 Hz behavior studied with an acoustic tracking array. Marine Mammal Science, 36 (3). https://www.researchgate.net/publication/339575220_Fin_whale_40-Hz_calling_behavior_studied_with_an_acoustic_tracking_array.

Imogen Lucciano, Graduate student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab.

One year ago, I packed up my 11-year-old daughter, Mavis (for the purposes of this blog, I’ll refer to her as “my sidekick”), our two dogs, and all our books and we moved to Oregon. I was thrilled to arrive and begin my graduate studies in cetacean ecology and bioacoutics with the GEMM lab and the Marine Mammal Institute. It has not been an easy set of tasks to achieve high standards in graduate school while maintaining a constant presence as a single mother, but I am honestly having the time of my life. I am involved in an amazing graduate program and I get to do it with my sidekick cheering me on and making my life feel very whole. This is why I am excited to write this blog reporting on the progression of my thesis and the incredible animals that I have the pleasure of studying: the fin whale.  

Fin whales (Balaenoptera physalus) are the second largest cetacean on the planet and are present in nearly all temperate and polar oceanic regions of the world (1). For my master’s thesis, I will focus solely on the fin whales within a detectable range of our team’s research area off the Oregon coast. In the Northern Hemisphere, fin whales are known to grow up to 23 meters in length and weigh up to 40-50 metric tons (2). They have a slender profile and can be further identified by their hook-shaped dorsal fin in addition to a V-shape on their back referred to as a “chevron” (Fig. 1). Fin whales are a baleen whale in the rorqual family, which have adapted lunge feeding as their primary foraging method (3). This species of whales is also classified as endangered (1), making them a key focal species for research in our modern times of shifting conditions in ocean environments.

Although I am working to correlate the acoustic detections of fin whales across space and time with environmental drivers (like temperature and chlorophyll concentration), as an aspiring cetacean bioacoustician, one of my other burning related questions is: How can fin whale vocalizations be utilized to differentiate populations across the oceans? Perhaps my analysis of fin whales off the Oregon coast can contribute to the pool of researchers studying this species worldwide to help understand drivers of fin whale vocalization variability.

Fin whales can travel great distances, yet their unique vocal renditions of repetitive pulse calls at either a 20 Hz or 40 Hz frequency have geographic patterns (4). These renditions are stereotyped by inter-pulse interval (IPI), which is the rate at which the pulses are detected (5). What’s even more interesting is that unlike many other large baleen whale species, there is little evidence of seasonal behavior and vocalization patterns (5) (Figs. 2 & 3). This suggests that fin whales might not make repetitive annual migrations to accommodate foraging and reproduction. Are these animals prey driven with exemplary senses for finding prey over incredibly large distances in the ocean? Are fin whales consistently present off the Oregon coast? What are their names? Bob, Lucinda, Frederick? There is much to ponder here.

This past summer the Holistic Assessment of Living marine resources off Oregon (HALO) team recovered its first six months of continuously collected acoustic data from three hydrophones moored at designated source locations off the Newport coast. Around the same time, I transplanted my sidekick and myself in Ithaca, New York for the summer, so I could spend my summer days learning to identify and log baleen whale calls among other acousticians at the K. Lisa Yang Center for Conservation Bioacoustics at Cornell University. This work would contribute to my preparation for the analysis of the HALO acoustic data.

I was less than a month into this work when my sidekick ended up spending an entire week with us in the lab because the counselors at her summer camp all caught COVID-19. My sidekick is a dedicated book worm and had no problem keeping herself busy while we all worked, however, she is young and vivacious and so she would often share her music and jokes with the group. I recall (with an uncontrollable smirk on my face) one of her songs called the “Oof” song (Video 1), that is literally a repetitive beat with the onomatopoeia, “oof” being played over and over again. When it started playing I looked up from my computer to see a row of researchers sitting next to Mavis all bobbing their heads to the repetitive tone of “oof”, a tone that hilariously reminded us of a sped-up version of the repetitive pulse of fin whale song. From that point on, “oof” has involuntarily become a part of our language among this group of acousticians.

The summer blazed by, Fall is here, and my sidekick and I are back in Oregon. I am in the process of organizing our collected HALO data to accommodate analysis of baleen whales, including fin whales. At this point I am already able to see fin whale calls in our data (Fig. 4). Subsequently, I will spend the next few months analyzing these data to determine the patterns of fin whale calls over time at our three observation sites (on the shelf, the shelf edge, and off the shelf). Within this analysis I will also look to define the vocal repertoire of fin whales over our six-month study period, which will allow me to report on the frequency where they are primarily detected and the IPI with which the pulses occur.

Moving forward, the HALO team will continuously retrieve and replace the three hydrophones to collect our acoustic data, returning a rich long-term dataset of the study area. I am eager to learn whether the fin whale IPI will remain the same in this location or show changes according to shifts in upwelling or seasonally, assuming they remain in the Northern California Current and do not migrate away. I will continue to assess the acoustic patterns of fin whales over the next year to describe their distribution patterns. All the while with the “oof” song stuck in my head and with my vivacious book worm head banging in the background.

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References

(1) Fin Whale. NOAA Fisheries. https://www.fisheries.noaa.gov/species/fin-whale.

(2) Aguilar, A. & Garcia-Vernet, R. 2018. Encyclopedia of Marine Mammals, Third Edition: Fin Whale, Balaenoptera physalus, Pg 369-371. Academic Press, ISBN 978-0-12-804327-1.

(3) Shadwick, R. et al. 2019. Lunge feeding in rorqual whales. Physiology, 34: 409-418. https://journals.physiology.org/doi/epdf/10.1152/physiol.00010.2019.  

(4) Oleson, E. et al. 2014. Synchronous seasonal change in fin whale song in the North Pacific. Plos ONE, 9 (12). https://doi.org/10.1371/journal.pone.0115678.

(5) Morano, J. et al. 2012. Seasonal and geographical patterns of fin whale song in the western North Atlantic Ocean. The Journal of the Acoustical Society of America, 132 (1207): 1207-1212. https://doi.org/10.1121/1.4730890.

(6) Helble, T. et al. 2020. Fin whale song patterns shift over time in the central North Pacific. Frontiers of Marine Science, 2 (Marine Megafauna). https://doi.org/10.3389/fmars.2020.587110.  

(7) Weirathmueller, M. et al. 2017. Spatial and temporal trends in fin whale vocalizations recorded in the NE Pacific Ocean between 2003-2013. Plos ONE, 12 (10): e0186127. https://doi.org/10.1371/journal.pone.0186127.

Imogen Lucciano, Graduate student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab.

Pursuing a graduate degree as a member of the Marine Mammal Institute (MMI) comes with many advantages. Developing associations with curious, industrious researchers and working with advanced technological methods are certainly two of them. Particularly, as a member of the HALO project, I have the pleasure of working alongside not only the GEMM’s, but also acoustician Dr. Holger Klinck and his bioacoustics team at the K. Lisa Yang Center for Conservation Bioacoustics at the Cornell Lab (CCB) who have made significant contributions to advance the field for marine mammal research.

When the HALO project kicked off in October, 2021, Holger and graduate student, Marissa Garcia, arrived for our initial voyage off the Oregon coast with three specialized acoustic recording devices, called Rockhoppers. We deployed each Rockhopper at their designated locations, where they will remain and be replaced every six months, to collect continuous passive acoustic data of cetacean vocalizations. These data are significant because they gather information on all vocalizing whales and dolphins within a detectable range of the Rockhoppers, supporting not only my thesis work concerning fin whale distribution in the Northern California Current (NCC) but has the potential to inform multiple other research projects as well.   

Passive acoustic monitoring (PAM) is a non-invasive underwater method of recording acoustic output of cetaceans (Zimmer, 2011), and the Rockhopper is specialized for this task. The Rockhopper relatively small (each weighing ~90lbs.) and can be easily deployed with a minimal team from almost any vessel (Fig 1). The mooring is a simple system that anchors the Rockhopper to the sea floor after it sinks through the water column, tolerating depths up to 3,500 m (Klinck et al., 2020). The device can stay on the ocean floor for up to seven months continuously collecting high-frequency data (up to 197 kHz, 24 bits; Klinck et al., 2020). To recover the Rockhopper, the mooring system (Fig 2) includes an acoustic release; when the correct acoustic signal is transmitted by scientists from the vessel and received down at the seafloor, the Rockhopper is released. It’s positive buoyancy allows it to float to the surface where it is recovered. By developing the Rockhopper with these capabilities, the bioacoustics team at Cornell University have taken several steps to enhance cetacean research.     

According to one of it’s designers, David Winiarski, the Rockhopper development team, consisting of himself, Holger Klinck, Raymond Mack, Christopher Tessaglia-Hymes, Dmitri Ponirakis, Peter Dugan, Christopher Jones, and Haru Matsumoto, initiated it’s construction in 2015. Winiarski states that Jones developed the Rockhopper’s initial PAM electronics at Embedded Ocean Systems (EOS), Boston, MA and then the rest of the team developed the remainder of the device in 2017. The Rockhopper contains the electronic system and a 10.8 V Lithium battery pack in an oil-filled Vitrovex 43 cm glass sphere that is encased in hard polyethelene. Two 64 GB memory cards store the collected acoustic data. About every hour the internal processing unit moves the data to two 4 Terabyte solid-state drives in a process that ensures the data is not lost (Klinck et al., 2020). Winiarski attests that it was quite a hectic process to get six complete Rockhoppers ready for their initial deployment, however the team succeeded and in May 2018 they were deployed in the Gulf of Mexico. The Rockhoppers were recovered in 2019 after six months, returning an amazing 21,522 hours of continuous acoustic data (Klinck et al., 2020).

Learning this information about the acoustic devices that will be responsible for collecting my Master’s thesis data is encouraging. I am eager to see the fin whale energy captured within the Rockhopper records. The HALO team, along with myself, Holger, and Marissa, will head back out off the Oregon coast to retrieve our three HALO-designated Rockhoppers in early June (next month). We will then spend the summer at Cornell reading through our first six months of data.

So, why call this acoustic device, the “Rockhopper”? Winiarski explained that since the CCB is a subsect of the Cornell Lab of Ornithology their projects tend to be named after birds. The Rockhopper team thought that this device should respectively be named after a cool marine megafauna. Hence the rockhopper penguin was chosen. I do agree that such an outstanding device is well suited in relation with an equally remarkable marine species.    

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References

Klinck, H., Winiarski, D., Mack, R., Tessaglia-Hymes, C., Ponirakis, D., Dugan, P., Jones, C., Matsumoto, H. 2020. The Rockhopper: a compact and extensible marine autonomous passive acoustic recording system,” Global Oceans 2020: Singapore – U.S. Gulf Coast: 1-7. https://ieeexplore.ieee.org/document/9388970. 

Zimmer, W. 2011. Passive acoustic monitoring of cetaceans. Cambridge University Press, Cambridge, UK.

Imogen Lucciano, Graduate student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab.

For marine science to be successful and impactful, it is crucial for collected data and results of analyses to be shared as widely as possible. This sharing should occur with the research community itself (which of course saves time and helps ignite the big, impactful ideas), and also amongst the public, in government, the fishing industry, big energy businesses, the military, and shipping industries as well. All these entities can relate in some way to the use of the oceans. Our increased collective knowledge can help us make conscious and intelligent management choices that will promote healthy oceans and in turn provide more resources to humans as well.

Though I am only just breaking the ice in my marine science education, I am already experiencing my first tastes of what this collaboration can look like. My graduate thesis focuses on the acoustic and observational detections of fin whales, an endangered species, as they relate to environmental characteristics in the NE Pacific. I am still in the early stages collecting data with the HALO project, but for now it is important to get started reviewing what’s currently available in the field. GEMM lab’s OPAL project, led by Dr. Leigh Torres and Dr. Solene Derville, was quick to provide me with their fin whale sightings data collected over the past few years, as well as share some of their great fin whale photos (Fig. 1). Clearly, I am already becoming rich through this association.

My career interests revolve around filling knowledge gaps of cetacean behaviors, so I often find myself associating what’s happening in my life to what I am reading currently as it relates to this field of research. My most recent blog, highlighted my need to relax occasionally with play and prompted me to consider how play is defined in cetacean behavior. So, with the ignition of my graduate research and this first aforementioned taste of scientific collaboration, I synaptically thought about a recent study of interspecies collaborative hunting between dolphins and humans that was co-authored by the Marine Mammal Institute’s Dr. Mauricio Cantor. Here, bottlenose dolphins who have learned to herd fish to shore, stick together and use their skills to move schools of fish toward local fishermen standing by with nets. The dolphins then provide a signal to the fishermen, the nets are cast at just the right time, and the dolphins forage on the fish trapped between the fishermen and the nets (Daura-Jorge, Cantor, et al., 2012). Both the dolphins and the fishermen greatly benefit by working together. I found this study thought-provoking; I have not seen anything quite like this interspecies association.

In the interest of potentially finding more cross-taxa cetacean relationships, I dug into the literature and found a few more interspecies associations to note. The first article that took me aback was a 2017 report detailing humpback whales defending other marine mammal species by interfering with the hunting practices of transient killer whales (Pitman et al., 2017). Killer whales are apex predators who hunt marine mammals, to include pinnipeds, adult baleen whales and often the calves of baleen whales. Slow, rotund baleen whales (right whales, gray whales, and humpbacks) are known to use their immense size and large appendages to fight off killer whales. What is unique with this study is that humpback whales were observed not only protecting their own calves from predation but also using a mobbing tactic to protect other cetacean species (minke whales, gray whales, Dall’s porpoises, and others) and pinnipeds (Steller sea lions, California sea lions, Weddell seals, and others; Fig. 2) as well, showing acts of potential altruism in cetaceans (Pitman et al., 2017).

The next interspecies association catching my eye came from studies detailing the two largest marine mammals, blue and fin whales, reproducing together. Though the two species are relatively alike in having large sleek physiques, they are very different in their known migratory and acoustic behaviors, so it doesn’t seem obvious or likely the two would mate. However, following the genetic testing of a whale near Iceland that displayed an unusual phenotype, researchers were able to determine that the whale did in fact contain the DNA of both species (Pampoulie et al., 2020). These blue/fin hybrids have been spotted in several locations worldwide and they are even found to be fertile. A recent study of a successfully tagged and observed blue/fin hybrid called, “Flue” (Fig. 3), co-authored by Dr. Daniel Palacios of MMI’s WHET Lab, found that though the animal possessed a phenotype mostly descriptive of fin whale, Flue appeared to follow blue whale migratory behavior (moving farther north along the California coast to forage in the summer and then moving to southern breeding ground waters along the coast of Mexico). These researchers suggest that blue/fin hybrid whales are common and postulate whether these animals are the source of an unmatched 52 Hz whale call sometimes recorded in the North Pacific (Jefferson et al., 2021).

Lastly (and perhaps my favorite of the papers of the collection), there is a report published in 2019 detailing a closely followed bottlenose dolphin female who adopted a young melon-headed whale calf near French Polynesia in the South Pacific (Fig. 4). Though cetaceans have been known to participate in allonursing, a form of alloparental care in which adult females will nurse another’s offspring of the same species, an interspecific adoption has rarely been reported. This mother-calf interspecies pair were observed together just after the adoptive mother gave birth to another calf, so it was impossible that the adopted calf was a potential hybrid. Furthermore, the two species have overlapping populations in this area of the South Pacific and thus it was concluded that the female dolphin had accepted a lost calf as her own (Carzon et al., 2019). Lactation is energetically costly, and considering the dolphin already had another calf to feed, the fact that she accepted the adopted calf, was observed nursing it, and developed a lengthy bond with it is remarkable.

I admit it was more fun than work to dig into these interspecies associations this week, because they depict how rich our world can be when animals (including humans) evoke positive associations across taxa. Reverting into my fin whale research, I cannot wait to see where my analysis will lead. I am eager to share my results, begin collaborations with other researchers and eventually present it to the public with the hopes of developing positive associations between humans and the marine world.

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Literature Cited

Carzon, P., Delfour, F., Dudzinski, K. et al. 2019. Cross-genus adoption in delphinids: One example with taxonomic discussion. Ethology: Behavioral Notes, 125: 669-676.

Daura-Jorge, F., Cantor, M., Ingram, S. et al. 2012. The structure of a bottlenose dolphin society is coupled to a unique foraging cooperation with artisanal fisherman. Biology Letters, 8: 702-705.

Jefferson, T., Palacios, D., Calambokidis, J. et al. 2021. Sightings and satellite tracking of a blue/fin whale hybrid in its wintering and summering ranges in the eastern north pacific. Advances in Oceanography & Marine Biology, 2 (4). http://dx.doi.org/10.33552/AOMB.2021.02.000545.  

Pampoulie, C., Gislason, D., Olafsdottir, G. et al. 2020. Evidence of unidirectional hybridization and second-generation adult hybrid between the two largest animals on Earth, the fin and blue whales. Evolutionary Applications, 14: 314-321.

Pitman, R., Deecke, V., Gabriele, C., et al. 2016. Humpback whales interfering when mammal-eating killer whales attack other species: Mobbing behavior and interspecific altruism? Marine Mammal Science, 33 (1): 7-58. https://doi.org/10.1111/mms.12343.

Imogen Lucciano, Graduate Student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab.

Since coming back from winter holiday, things have picked back up to my normal pace of GO! and I’ve taken little to no “down time” in my awaken hours. As a grad student who is also a mother to an active 11-year-old daughter and two dogs, my days are packed. Although I do enjoy a life of steady movement and accomplishment, I also need to do “nothing” sometimes, like a recluse who needs to see the sun on occasion. So, this evening I decided that I would have a night of fun and I took my daughter to see a movie. We haven’t been to the movies much since the pandemic started, but it is one of our most beloved things to do. I heard the theatres were like ghost towns since the recent omicron surge anyway, so we showed up and were one of two families there. We picked a comedy and ordered a bucket of popcorn, nachos (no jalapeños, just the cheese), slurpies, soft pretzels, and sour patch kids (I told the cashier to have two wheelchairs ready to haul us out of there post feast). We laughed and sang and by the near end of the movie, I had a moment of self-realization: I felt really relaxed. This epiphany was synaptically followed by thinking about how cetaceans engage in play.

Humans often recognize play through sports or games, and mostly through smiling and the vocalization of laughter. If we’re laughing it usually means that we are not aggressing. From what we currently understand, play in cetaceans has evolved as an ontogenetic behavior in many species for the purposes of developing survival skills (Paulos et al., 2010). This “purpose of play” makes a lot of sense, and I see it in my dogs when they are growling, snapping, tugging rope, and chasing each other in the yard. They are having the time of their lives and certainly not really fighting one another, yet they are also clearly practicing important skills if they were to come across predators or prey in the wild.

Most cetaceans vocalize often, whether in the form of pulsed calls, whistles, screams, songs, clicks or combination calls. The element of play associated with a utilized sound or other behavior opens the door for cetaceans to develop important social relationships among conspecifics, as well as developing crucial survival skills (Paulos et al., 2010). To quantify the vocal signals produced by cetacean species, researchers examine their complex repertoires to understand more about the function of certain sounds made specifically during play (Boisseau, 2004). Bottlenose dolphins provide each other with a distinct signal, pulse whistles that start around 13 kHz and end at around 10 kHz (Fig 1), to tell one another that the behavior they are exhibiting is play rather than aggression (Blomqvist et al., 2005).

Cetacean play is defined as behavior that is spontaneous, intentional, pleasurable, and rewarding (Hill et al., 2017). Although cetacean play is conducted in a relaxed setting when there is no immediate need for survival, it has a role in growth and sociability (Hill et al., 2017). For example, cetaceans participate in interspecies play, where they actively engage with one another for no apparent ecological benefit (excluding periods of symbiotic behavior, such as working together to herd prey). Yet, these periods of interspecies play may suggest that these animals are comfortable practicing for real world situations with one another. Large baleen whales have few predators and thus have opportunities to engage in play with pods of dolphins. In some cases, large baleen whales such as humpback and gray whales will lift smaller mammals out of the water, possibly to practice for maternal care (Hill et al., 2017).

Cetaceans engage in play not only with one another, but as solitary individuals as well. This play (which can occur parallel to conspecifics simultaneously) includes surfing, aerial breaches and leaps, slapping the surface of the water with a fin or tail fluke, and erratic swimming (Paulos et al., 2010). Some cetaceans play with objects they find in the wild. One example being bowhead whales, which are known to balance, sink, and lift logs (Paulos et al., 2010).

Another interesting cetacean play behavior is bubble blowing. Though humpback whales blow bubbles as a means of trapping prey while foraging (Moreno & Macgregor, 2019), beluga whales, particularly females, blow mouth ring bubbles and perform blowhole bursts when engaging in solitary play (Hill et al., 2011). Just for the fun of it. It appears that cetaceans also need to be actively involved in “nothing” sometimes, as there is some good use for it. For me, engaging in play is a way to reset and relax, which is necessary even for those us who gain a lot of pleasure from our accomplishments. As I sit in the desolate theatre connecting with my daughter and nurturing my own needs, I feel completely justified in my relaxing night off. Pass the nachos, please.

Literature Cited

Blomqvist, C., Mello, I., Amundin, M. 2005. An acoustic play-fight signal in bottlenose dolphins (Tursiops truncatus) in human care. Aquatic Mammals, 31 (2), 187-194. 

Boisseau, O. 2004. Quantifying the acoustic repertoire of a population: The vocalizations of free-ranging bottlenose dolphins in Fiordland, New Zealand. The Journal of the Acoustical Society of America, 117, 2318-2329. https://doi.org/10.1121/1.1861692.

Hill, H., Dietrich, S., Cappiello, B. 2017. Learning to play: A review and theoretical investigation of the development mechanisms and functions of cetacean play. Learning & Behavior, 45, 335-354. https://link.springer.com/content/pdf/10.3758/s13420-017-0291-0.pdf.

Hill, H., Kahn, M., Brilliott, L., Roberts, B., Gutierrez, C. 2011. Beluga (Delphinaptera leucas) bubble bursts: surprise, protection, or play? International Journal of Comparative Psychology, 24, 235-243.

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Imogen Lucciano, Graduate Student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab. Marissa Garcia, Graduate Student, Cornell Department of Ornithology Center for Conservation Bioacoustics.

There is nothing quite like the excitement of starting a fresh project, and the newly organized Holistic Assessment of Living marine resources off the Oregon coast (HALO) project team was alive with it on 8 October as we prepared our various elements of research gear aboard the R/V Pacific Storm in the Newport bayfront (Fig 1). The weather was predicted suitable enough for our 24-hour trip out along the Newport Hydrographic line (NHL; Fig 2), and so we focused on the questions of whether we had remembered to pack each necessary piece of equipment, whether we had sufficiently charged and calibrated each bit of gear, whether we had enough snacks, and the most looming question of all, what would we see and hear when we get out there? The species guessing game only enhanced the thrill of our departure.

Figure 1. The R/V Pacific Storm docked at the Newport bayfront. Photo: Rachel Kaplan.

The HALO project aims to fill gaps in knowledge on the abundance and distribution of cetaceans off the Oregon coast, and relative to ongoing climate change and marine renewable energy development projects along the Oregon coast. The core of the HALO project is deployment of three hydrophones to record year-round cetacean vocalizations in the same area where we will conduct visual line surveys for cetaceans monthly in addition to mapping prey. Needless to say, we (the grad student authors of this blog) feel humbled and grateful to be on the project – not to mention, eager to gain our sea legs like the rest of the pros on the team and boat crew (much sea sickness meds were at the ready!).

This HALO team is well stacked, engaging the expertise and specialties of researchers from three different schools of science. Leigh Torres of the Marine Mammal Institute (MMI)’s GEMM lab (assisted by newcomer graduate student, Miranda Mayhall/coauthor of this post) brings to the project the knowledge of visual survey distance sampling data collection and analysis and will work alongside Craig Hayslip of MMI who will serve as lead visual observer. The visual sightings will inform us on cetacean occurrence patterns in the region. Since cetaceans also spend a great deal of time underwater, Holger Klinck, an expert bioacoustician from Cornell University and affiliate MMI professor (with graduate student Marissa Garcia, also a coauthor of this blog) will oversee the deployment of specialized hydrophones along our research line to record acoustic data. After the hydrophones are deployed, and while we are on-survey looking for cetaceans, we will also run a EK60 transducer (A.K. echosounder) to record backscatter data on prey in the area. This aspect of HALO brings in the third element of research from OSU’s College of Earth, Ocean, and Atmospheric Sciences (CEOAS) Zooplankton Ecology Lab, Kim Bernard who is leading the effort to collect and analyze prey data. During this first voyage, Rachel Kaplan, a grad student of both the GEMM lab and Zooplankton Ecology Labs, came along to run the echosounder and ensure data quality.

Figure 2. HALO’s research track-line: a 40-mile stretch along the Newport Hydrographic Line (NHL) from NH65 to NH25. The three points indicate the locations of the three deployed hydrophones.

With the sun nearly set, the R/V Pacific Storm left the dock at 7pm, pushing from Yaquina Bay out to the Pacific along the NHL hopping over swells that rocked the boat. Despite our strong-willed confidence, it was tough then to focus on anything but maintaining personal physiological equilibrium. Darkness surrounded the vessel, and we wouldn’t be able to see much of the Pacific Ocean until morning. It would take us nearly eleven hours to reach our first destination, 65 miles offshore (NH65) at which point all the activities would begin. All we could do was brace through the evening and hope that by dawn the dizziness would subside. We had field work adventures ahead! So, the focus went from extreme high energy to tucking in and allowing the Storm’s highly experienced crew to maintain watch and bring us to our first destination.   

Figure 3. The research lab room on the R/V Pacific Storm with four eager scientists just as team HALO departed Yaquina Bay; from the left Holger Klinck, Marissa Garcia, Rachel Kaplan & Leigh Torres. Photo: Miranda Mayhall.

At sunrise, the team rose to their feet, and we (the grad students) did what we could to muster the energy to crawl up the stairs, snap on lifejackets and ample out on the boat deck. Despite our condition, we looked out to a sight unlike anything we had ever seen before. The ocean was a deep purple, with flecks of orange bordering the horizon behind fluffy, indigo clouds. We were at NH65, and at this point it was time to deploy the first Rockhopper, a specialized hydrophone developed at Cornell lab of Ornithology, with the capability of recording at a high sampling rate (394 kHz), which allows it to detect and record most marine mammal species. In this case, we were recording at 197 kHz, only leaving our porpoises from the recordings.

Although the acoustic team has extensively prepared the hydrophones for deployment, nothing quite prepared us for focusing on the final connections and tests on the back deck while the boat rocked back and forth. The team initiated the Rockhopper for recording, and then we proceeded with setting up the mooring — connecting the Rockhopper to the acoustic release, float, and weights. We then slowly slid it off the edge of the boat, and there it went into the ocean, where it will record for six months, approximately 3,000 meters under the surface.

Figure 4. The HALO team prepared the Rockhopper (the orange orb-like device) for deployment; from the left, Craig Hayslip, Holger Klinck, and Marissa Garcia. Photo: Rachel Kaplan.

 Once the first Rockhopper was deployed, making its way to the ocean floor, the “transducer pole” was deployed off the side of the vessel to collect echosounder data and the long endeavor of conducting visual survey for the length of the research line began. Observers were glued to binoculars, scouring the sea for the presence of cetaceans, as the ocean swell rocked the boat on our journey eastward. Those with an appetite nibbled on Tony’s Chocoloney chocolate bars (Thanks, Leigh!), breaking off pieces and passing around the bar to each visual observer — an optimal fuel for remaining attentive.

Figure 5. HALO team up on the flying bridge; Observers clockwise from the lower left: Leigh Torres, Marissa Garcia, Craig Hayslip, Miranda Mayhall, Holger Klinck.

During visual survey effort, we observe from the flying bridge the entire front 180 degrees of the vessel trackline, all the while recording data on where we do and don’t see cetaceans (presence and absence data). During this survey effort we record the sighting conditions (visibility, sea state, glare), and when we see cetaceans we record the distance to the marine mammals from the boat, the species identification, and the number of animals in the sighting. We use a program called SeaScribe to collect our data. As we use the data collection protocols on each of the 12 planned monthly surveys, we will obtain a valuable, standardized dataset that can be analyzed relative to environmental conditions and in comparison, to the acoustic data to understand cetacean distribution patterns. The survey pressed on, and all the while the echosounder was actively recording prey availability data, with Rachel Kaplan at the control. 

Figure 6. Rachel Kaplan monitoring the incoming data from the transducer on the SIMRAD EK60. Photo: Marissa Garcia.

Over the course of the survey, the visual team spotted northern right whale dolphins, a fin whale, a small group of killer whales and many scattered humpback whales. All three Rockhoppers were deployed at their intended locations at NH65, NH45, and then NH25. The echosounder successfully collected backscatter data for the duration of the survey, and interestingly we noticed increased prey on the echosounder at the same time as we observed the humpbacks. Already we are detecting connections between the environment and cetaceans!           

Figure 8. Fin whale spotted while on our first HALO survey. Photo: Leigh Torres, NOAA/NMFS permit # 21678

After nearly twelve hours conducting field work, the shoreline was close in sight, and we stopped our survey effort. For the first time all day, we all collectively sat in the vessel’s laboratory, finally putting our feet up to rest. We pulled back into Newport harbor around 7:00 pm, with the first HALO cruise successfully in the books. And though we visually observed many cetaceans and collected prey data, we still couldn’t help wondering what the Rockhoppers were recording at the bottom of the ocean. The thought of getting back out there for more surveys and retrieving the sound data keeps our momentum in full swing. For the next 11 months (and hopefully longer!) we will conduct the same 24 hr. cruise. The future is exciting, and we can’t wait to report back on our future trips and research findings.

Figure 9. The HALO team walking along the dock to their cars in Newport, Oregon, heading home after cruise #1. Photo: Miranda Mayhall.

This project was funded by sales and renewals of the special Oregon whale license plate, which benefits MMI. We gratefully thank all the gray whale license plate holders, who made this research trip possible.