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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.    

Left: Rockhopper penguins on a New Zealand hillside. https://nzbirdsonline.org.nz/species/eastern-rockhopper-penguin Upper right: Chris Tessaglia-Hymes and David Winiarski with a Rockhopper acoustic device. Lower right: The first six complete Rockhopper acoustic devices developed at the Cornell Center of Bioacoustics in 2017.

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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.

Allison Dawn, GEMM Lab Master’s student, OSU Department of Fisheries, Wildlife and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

As the first year of my Master’s is coming to an end, I am excited to have completed the first milestone of writing my research proposal. During the formation of my initial hypotheses, I have been thinking deeply about the potential drivers of zooplankton variability, and how these metrics relate to the Pacific Coast Feeding Group (PCFG) of gray whales foraging in Port Orford. One topic that continues to appear in the literature and throughout my coursework is that of the extreme marine heat wave (MHW) event (2013-2016) in the Pacific Ocean, otherwise known as the “warm blob”. In Dawn’s (now Dr. Barlow!) blog about this MHW, she discusses how whale habitat in California was compressed due to shifts in prey availability, and how this led to an increased number of whale entanglements (Santora et al., 2020). While sea surface temperature (SST) is only one of many factors that influence prey metrics, it is nevertheless an important factor to consider, especially as these heat waves are expected to increase in intensity and duration due to climate change (Joh and Di Lorenzo, 2017). As Lisa mentioned in her last blog, the “warm blob” exacerbated the loss of kelp and sea stars, which is now impacting multiple trophic levels in Port Orford. For my first thesis chapter, I plan to dive into how SST anomalies impact the mosaic of interactions at our study site in Port Orford, and ultimately try to better understand food availability for the PCFG whales.

Cavole et al., 2016 is one of the early comprehensive studies to discuss the impact of the blob on a variety of planktonic marine species. Their sea surface temperature anomaly figure (Figure 1) shows where the anomaly began in 2013 and how it migrated from the Northern Pacific to the Southern Pacific coast.

Figure 1. Plots showing the SST anomalies as the “warm blob” migrated from the Northern Pacific to the Southern Pacific from 2013 until 2016.

Among many other impacts, this MHW caused a reduction in phytoplankton, the major food source for zooplankton. The decline of this food source subsequently caused significant changes in zooplankton populations. Specifically, studies on copepod diversity and biomass show that in a typical California Current System (CCS) there is a seasonal oscillation between warm-water with subtropical species and cold-water with subarctic species. In the winter, the CCS is characterized by a high diversity of subtropical species, due to a southern water source. In the spring, northern cold water advection brings low-diversity, subarctic copepods. While the timing of these shifts is subject to change due to changes in the Pacific Decadal Oscillation (PDO), it remains that these subtropical copepod species are known to be smaller and less nutritious than subarctic copepod species regardless of arrival time (Kintisch, 2015; Leising et al., 2015). However, in 2015, this shift to cold water copepod species did not occur, but rather coastal sampling along the Oregon coast saw subtropical copepod species prevail. Specifically, there were 17 main subtropical copepod species that dominated the species composition while the nutrient-rich arctic species were rare. This occurrence of major copepod shifts alone points to the overall concern for the ecosystem imbalance, to the detriment of top predators like marine mammals and seabirds (the “losers”), and others gaining advantage (the “winners”) (Figure 2).

Figure 2. Figure showing the “losers” (right column) and “winners” (left column) of MHW impacts. Species are organized by trophic level, with top predators at the bottom. Taken from Cavole et al., 2016.

More recent studies found that in certain areas, impacts from the “warm blob” outlived the duration of the larger scale anomaly. In fact, large, positive SST anomalies have lingered on the Oregon shelf until at least September 2017 (Peterson et al., 2017). During this time period, anomalously high abundances of nearshore larval North Pacific krill (Euphausia pacifica) were collected off of the Newport Hydrographic Station (Morgan et al., 2019). Additionally, Brodeur et al. (2019) demonstrate that while indicator species in the nearshore have consistent annual variability, there were substantial differences between community composition between 2011-2014 (low diversity) and 2015-2016 (high diversity). This work also documented the shift from crustacean species (like krill and mysids) to more low-quality gelatinous taxa. As the authors acknowledge, this change in prey community assemblage could have major negative impacts on trophic interactions. This is especially true in the context of whales, as they are not known to rely on gelatinous taxa for energy.

Just like our summer sampling in Port Orford, these studies only provide a “snapshot” of plankton species abundance and composition during a particular time of year. However, even a snapshot can reveal significant changes in prey variability, which then may help us understand the drivers of PCFG habitat utilization. We are actively investigating whether there have been significant changes in the variability of several zooplankton metrics (abundance, distribution, size class, composition) relative to SST changes in Port Orford over the last 6 years (2016-2021).

We will also consider multiple other static and dynamic factors that could influence zooplankton patterns (e.g., upwelling strength, kelp health, tidal height, topography); however, given these documented strong relationships between the zooplankton community and SST across the North Pacific, we hypothesize similar impacts in our Port Orford study region. For example, in certain sampling years, net tows seemed to be comprised of smaller size classes of zooplankton than usual. We will consider how size class availability has changed and if this was driven by SST variability. Gray whales are drawn to this area for enhanced feeding opportunities, and understanding the drivers of zooplankton, especially high quality prey, is a key step to understanding whale use of the area.

Please stay tuned for more updates as we continue working towards the answer to these pressing questions!

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References

Brodeur, R. D., Auth, T. D., & Phillips, A. J. (2019). Major shifts in pelagic micronekton and macrozooplankton community structure in an upwelling ecosystem related to an unprecedented marine heatwave. Frontiers in Marine Science, 6, 212.

Cavole, L. M., Demko, A. M., Diner, R. E., Giddings, A., Koester, I., Pagniello, C. M., … & Franks, P. J. (2016). Biological impacts of the 2013–2015 warm-water anomaly in the Northeast Pacific: winners, losers, and the future. Oceanography, 29(2), 273-285.

Joh, Y., & Di Lorenzo, E. (2017). Increasing coupling between NPGO and PDO leads to prolonged marine heatwaves in the Northeast Pacific. Geophysical Research Letters, 44(22), 11-663.

Kintisch, E. (2015). ‘The Blob’ invades Pacific, flummoxing climate experts.

​​Leising, A. W., Schroeder, I. D., Bograd, S. J., Abell, J., Durazo, R., Gaxiola-Castro, G., … & Warybok, P. (2015). State of the California Current 2014-15: Impacts of the Warm-Water” Blob”. California Cooperative Oceanic Fisheries Investigations Reports, 56.

Morgan, C. A., Beckman, B. R., Weitkamp, L. A., & Fresh, K. L. (2019). Recent ecosystem disturbance in the Northern California current. Fisheries, 44(10), 465-474.

NOAA Fisheries. 2015b. California Current Integrated Ecosystem Assessment (CCIEA) State of the California Current Report, 2015. NMFS Report 2.
Santora, J. A., Mantua, N. J., Schroeder, I. D., Field, J. C., Hazen, E. L., Bograd, S. J., … & Forney, K. A. (2020). Habitat compression and ecosystem shifts as potential links between marine heatwave and record whale entanglements. Nature communications, 11(1), 1-12.

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.

Moreno, K. & Macgregor, R. 2019. Bubble trails, bursts, rings, and more: A review of multiple bubble types produced by cetaceans. Animal Behavior and Cognition, 6 (2), 105-126. https://www.animalbehaviorandcognition.org/uploads/journals/23/AB_C_Vol6(2)_Moreno_Macgregor.pdf.

Paulos, R., Trone, M., Kuczaj II, S. 2010. Play in wild and captive cetaceans. International Journal of Comparative Psychology, 23, 701-722.

Provine, R. 2016. Laughter as an approach to vocal evolution: The bipedal theory. Psychonomic Bulletin & Review, 24, ­238-244. https://link.springer.com/content/pdf/10.3758/s13423-016-1089-3.pdf.