Into the Krillscape: A Remote Expedition in Research and Mentorship

By Rachel Kaplan, PhD student, Oregon State University College of Earth, Ocean, and Atmospheric Sciences and Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

What are the most unexpected things you’ve done on Zoom in the last year? Since the pandemic dramatically changed all our lives in 2020, I think we’ve all been surprised by the diversity of things we’ve done remotely. I’ve baked bagels with a friend in Finland, done oceanography labs from my kitchen, had dance parties with people across the country, and conducted an award ceremony for my family’s Thanksgiving scavenger hunt – all on Zoom. Over the last several months, I’ve also mentored an Undergraduate Research, Scholarship, & the Arts (URSA) Engage student, named Amanda. Although we haven’t met in person yet, we’ve been connecting over Zoom since October. 

Amanda is an Ocean Sciences student working with me and Dr. Kim Bernard (CEOAS) to conduct a literature review about the two species of krill found off the coast of Oregon. Thysanoessa spinifera and Euphausia pacifica are an important food source for many of the animals that live off our coast — including blue, humpback, and fin whales. I am trying to learn how krill distributions shape those of humpback and blue whales as part of project OPAL, as well as which oceanographic factors drive krill abundances and distributions.

Thysanoessa spinifera (source: Scripps Institute of Oceanography). 

We’re also interested in T. spinifera and E. pacifica for the crucial roles they serve in ecosystems, beyond providing dinner for whales. Krill do many things that are beneficial to ecosystems and people, termed “ecosystem services.” These include facilitating carbon drawdown from the surface ocean to the deep, supporting lucrative fisheries species like salmon, flatfish, and rockfish, and feeding seabirds like auklets and shearwaters. We want to understand more fully the niche that T. spinifera and E. pacifica each fill off the coast of Oregon, which will help us anticipate how these important animals can be impacted by forces such as global climate change and marine management efforts.

Trying to understand the ecosystem services fulfilled by krill is inherently interdisciplinary, which means we have to learn a lot of new things, making this project a lot of fun. The questions Amanda and I have pursued together have ranged from intensely specific, to surprisingly broad. How many calories do blue whales need to eat in a day? How many krill do salmon need to eat? How big are krill fecal pellets, and how fast do they sink?

Trying to answer these questions has basically amounted to a heroic scouring of the internet’s krillscape by Amanda. She has hunted down papers dating back to the 1960s, pulled together findings from every corner of the world, and pursued what she refers to as “treasure troves” of data. In the process, she has also revealed the holes that exist in the literature, and given us new questions. This is the basis of the scientific process: understanding the current state of knowledge, identifying gaps in that knowledge, and developing the questions and methods needed to fill those gaps.

Euphausia pacifica (source: University of Irvine California, Peter J. Bryant).

Filling in knowledge gaps about T. spinifera and E. pacifica can help us better understand these animals, the ecosystems where they live, and the whales and other animals that depend on them for prey. It’s exciting to know that we will have the opportunity to help fill some of these gaps, as both Amanda and I continue this research over the course of our degrees.

Being able to engage in remote research and mentorship has been really rewarding, and it has shown me how far we’ve all come over the last year. Learning how to work together remotely has been crucial as we have adjusted to the funny new normal of the pandemic. As much as I miss working with people in person, I’ve learned that there’s a lot of great connection to be found even in remote collaboration – I’ve loved meeting Amanda’s pets on Zoom, learning about her career goals, and seeing her incredibly artistic representations of the carbon cycle held up to the camera.

Even though most of our conversations take place on Zoom from our homes, this research still feels plugged into a bigger community. Amanda and I also join Kim’s bigger Zooplankton Ecology Lab meetings, which include two other graduate students and eight undergraduate students, all of whom are working on zooplankton ecology questions that span from the Arctic to the Antarctic. Even though we’ve never met in person, a supportive and curious community has developed among all of us, which I know will persist when we can move back to in-person research and mentorship.

The right tool for the job: examining the links between animal behavior, morphology and habitat

Clara Bird, PhD Student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

In order to understand a species’ distribution, spatial ecologists assess which habitat characteristics are most often associated with a species’ presence. Incorporating behavior data can improve this analysis by revealing the functional use of each habitat type, which can help scientists and managers assign relative value to different habitat types. For example, habitat used for foraging is often more important than habitat that a species just travels through. Further complexity is added when we consider that some species, such as gray whales, employ a variety of foraging tactics on a variety of prey types that are associated with different habitats. If individual foraging tactic specialization is present, different foraging habitats could be valuable to specific subgroups that use each tactic. Consequently, for a population that uses a variety of foraging tactics, it’s important to study the associations between tactics and habitat characteristics.

Lukoschek and McCormick’s (2001) study investigating the spatial distribution of a benthic fish species’ foraging behavior is a great example of combining data on behavior, habitat, and morphology.  They collected data on the diet composition of individual fish categorized into different size classes (small, medium, and large) and what foraging tactics were used in which reef zones and habitat types. The foraging tactics ranged from feeding in the water column to digging (at a range of depths) in the benthic substrate. The results showed that an interesting combination of fish behavior and morphology explained the observed diet composition and spatial distribution patterns. Small fish foraged in shallower water, on smaller prey, and primarily employed the water column and shallow digging tactics. In contrast, large fish foraged in deep water, on larger prey, and primarily fed by digging deeper into the seafloor (Figure 1). This pattern is explained by both morphology and behavior. Morphologically, the size of the feeding apparatus (mouth gape size) affects the size of the prey that a fish can feed on. The gape of the small fish is not large enough to eat the larger prey that large fish are able to consume. Behaviorally, predation risk also affects habitat selection and tactic use. Small fish are at higher risk of being predated on, so they remain in shallow areas where they are more protected from predators and they don’t dig as deep to forage because they need to be able to keep an eye out for predators. Interestingly, while they found a relationship between the morphology of the fish and habitat use, they did not find an association between specific feeding tactics and habitat types.

Figure 1. Figure from Lukoschek and McCormick (2001) showing that small fish (black bar) were found in shallow habitat while large fish (white bar) were found in deep habitat.

Conversely, Torres and Read (2009) did find associations between theforaging tactics of bottlenose dolphins in Florida Bay, FL and habitat type. Dolphins in this bay employ three foraging tactics: herd and chase, mud ring feeding, and deep diving. Observations of the foraging tactics were linked to habitat characteristics and individual dolphins. The study found that these tactics are spatially structured by depth (Figure 2), with deep diving occurring in deep water whereas mud ring feeding occurrs in shallower water. They also found evidence of individual specialization! Individuals that were observed deep diving were not observed mud ring feeding and vice-versa. Furthermore, they found that individuals were found in the habitat type associated with their preferred tactic regardless of whether they were foraging or not. This result indicates that individual dolphins in this bay have a foraging tactic they prefer and tend to stay in the corresponding habitat type. These findings are really intriguing and raise interesting questions regarding how these tactics and specializations are developed or learned. These are questions that I am also interested in asking as part of my thesis.

Figure 2. Figure from Torres and Read (2009) showing that deep diving is associated with deeper habitat while mud ring feeding is associated with shallow habitat.

Both of these studies are cool examples that, combined, exemplify questions I am interested in examining using our study population of Pacific Coast Feeding Group (PCFG) gray whales. Like both studies, I am interested in assessing how specific foraging tactics are associated with habitat types. Our hypothesis is that different prey types live in different habitat types, so each tactic corresponds to the best way to feed on that prey type in that habitat. While predation risk doesn’t have as much of an effect on foraging gray whales as it does on small benthic fish, I do wonder how disturbance from boats could similarly affect tactic preference and spatial distribution. I am also curious to see if depth has an effect on tactic choice by using the morphology data from our drone-based photogrammetry. Given that these whales forage in water that is sometimes as deep as they are long, it stands to reason that maneuverability would affect tactic use. As described in a previous blog, I’m also looking for evidence of individual specialization. It will be fascinating to see how foraging preference relates to space use, habitat preference, and morphology.

These studies demonstrate the complexity involved in studying a population’s relationship to its habitat. Such research involves considering the morphology and physiology of the animals, their social, individual, foraging, and predator-prey behaviors, and the relationship between their prey and the habitat. It’s a bit daunting but mostly really exciting because better understanding each puzzle piece improves our ability to estimate how these animals will react to changing environmental conditions.

While I don’t have any answers to these questions yet, I will be working with a National Science Foundation Research Experience for Undergraduates intern this summer to develop a habitat map of our study area that will be used in this analysis and potentially answer some preliminary questions about PCFG gray whale habitat use patterns. So, stay tuned to hear more about our work this summer!

References

Lukoschek, V., & McCormick, M. (2001). Ontogeny of diet changes in a tropical benthic carnivorous fish, Parupeneus barberinus (Mullidae): Relationship between foraging behaviour, habitat use, jaw size, and prey selection. Marine Biology, 138(6), 1099–1113. https://doi.org/10.1007/s002270000530

Torres, L. G., & Read, A. J. (2009). Where to catch a fish? The influence of foraging tactics on the ecology of bottlenose dolphins ( Tursiops truncatus ) in Florida Bay, Florida. Marine Mammal Science, 25(4), 797–815. https://doi.org/10.1111/j.1748-7692.2009.00297.x

Cetacean strandings and unusual mortality events: Why do cetaceans beach?

By Alejandro Fernandez Ajo, PhD student in the Department of Biology, Northern Arizona University, visiting scientist in the GEMM Lab working on the gray whale physiology and ecology project  

When a cetacean (whales and dolphins) is ashore or trapped in nearshore waters and cannot return to the open waters, it is considered stranded. Frequently, the stranded animal is in distress, dying, or dead. Although rare, the stranded cetacean can be a healthy animal trapped due to changes in tide or disorientation. Every year many cetacean strandings are reported from along the coasts around the world, and likely many more stranding events go unnoticed when they occur in remote areas. In all cases, the question is: why do cetaceans beach?

Southern right whales stranded at the coast of Peninsula Valdés, Patagonia-Argentina. Photo: Matias DiMartino / Southern Right Whale Health Monitoring Program.

There may be different causes for whales and dolphins to strand on beaches, either dead or alive. Understanding and investigating the causes of cetaceans strandings is critical because they can be indicators of ocean health, can help identify anthropogenic sources of disturbance, and can give insights into larger environmental issues that may also have implications for human health (NOAA). In this context, when scientists are analyzing a stranding event, they consider both possibilities that the event was natural or human-caused and classify strandings according to specific characteristics to study the causes of these events.

Types of cetacean strandings:

Live or Dead Stranding:

A stranding can involve live animals or dead animals if the death occurs in the sea and the body is thrown ashore by wind or currents. In live strandings, when they occur near urbanized areas, usually significant efforts are made to rescue and return the animals to the water; with small odontocetes, sometimes there is success, and animals can be rescued. However, when large whales are beached alive, their own weight out of the water can compress their organs and can cause irreversible internal damage. Although not externally visible, such damage can sometimes cause the death of the animal even after returning to the sea.

According to the number of individuals:

Single strandings occur when only a single specimen is affected at the time. The cetaceans that most frequently strand individually are the baleen (or mysticete) whales, such as right and humpback whales, due to their often solitary habits.

Mass strandings comprise two or more specimens, and in some cases, it can involve tens or even a few hundred animals. The mass strandings are more frequently observed for the odontocetes, such as pilot whales, false killer whales, and sperm whales with more complex social structures and gregarious habits.

Left: Single southern right whale calf stranded at the coast of Peninsula Valdés, Patagonia-Argentina. Ph.: Mariano Sironi / ICB. Right: Mass stranding of common dolphins in Patagonia-Argentina. Photo: www.elpais.com

Unusual Mortality Events

The Marine Mammal Protection Act defines an unusual mortality event (UME) as a stranding event that is unexpected, involves a significant die-off of any marine mammal population, and demands immediate response. Seven criteria make a mortality event “unusual.” Source: https://www.fisheries.noaa.gov.

  1. A marked increase in the magnitude or a marked change in morbidity, mortality, or strandings when compared with prior records.
  2. A temporal change in morbidity, mortality, or strandings is occurring.
  3. A spatial change in morbidity, mortality, or strandings is occurring.
  4. The species, age, or sex composition of the affected animals is different than that of animals that are normally affected.
  5. Affected animals exhibit similar or unusual pathologic findings, behavior patterns, clinical signs, or general physical condition (e.g., blubber thickness).
  6. Potentially significant morbidity, mortality, or stranding is observed in species, stocks, or populations that are particularly vulnerable (e.g., listed as depleted, threatened, or endangered, or declining). For example, stranding of three or four right whales may be cause for great concern, whereas stranding of a similar number of fin whales may not.
  7. Morbidity is observed concurrent with or as part of an unexplained continual decline of a marine mammal population, stock, or species.

The purpose of the classification of a mortality event as a UME is to activate an emergency response that aims to minimize deaths, determine the event cause, or causes, determine the effect of the event on the population, and identify the role of environmental parameters in the event. Such classification authorizes a federal investigation that is led by the expertise of the Working Group on Marine Mammal Unusual Mortality Events to investigate the event. This working group is comprised of experts from scientific and academic institutions, conservation organizations, and state and federal agencies, all of whom work closely with stranding networks and have a wide variety of experience in biology, toxicology, pathology, ecology, and epidemiology.

Southern right whale necropsy and external measurements. Source: Southern Right Whale Health Monitoring Program / ICB.

What can be learned from strandings and UMEs?

Examining stranded marine mammals can provide valuable insight into marine mammal health and identify environmental factors leading to strandings. Through forensic examinations, the aim is to identify possible risks to whales’ health and evaluate their susceptibility to diseases, pollutants, and other stressors. This information can contribute to cetacean conservation through informed management strategies. However, the quality of the data derived from a necropsy (the postmortem examination of carcasses) is highly contingent upon how early the stranding event is reported. As soon as the animal is deceased, decomposition starts, hindering the possibilities of detailed investigations of the cause of death.

Therefore, a solid network that can report and respond quickly to a stranding event is fundamental; this includes trained personnel, infrastructure, funding, and expertise to respond in a manner that provides for animal welfare (in the case of live strandings) and obtains data on marine mammal health and causes of death. Moreover, a coordinated international organization that integrates national marine mammal stranding networks has also been identifying as a critical aspect to enable adequate response to such mortality events. In many locations and countries around the world, funding, logistical support, and training remain challenging to stranding response.

In response to these concerns and needs, at the last World Marine Mammal Conference, which took place in Barcelona in December of 2019, The Global Stranding Network was founded to “enhance and strengthen international collaboration to (1) ensure consistent, high-quality response to stranded marine mammals globally, and (2) support conservation efforts for species under threat of extinction.” Monitoring marine mammal health worldwide can guide conservation and help identify priority areas for management (Gulland and Stockin, 2020).

What to do in case of finding a whale or dolphin on the beach?

When strandings occur, it is essential to know how to act. Unfortunately, untrained people, often with good intentions, can worsen the situation of stress and injury to the animal or can put themselves at risk of injury or exposure to pathogens. If you find a cetacean alive or dead on the beach, the most important things to do are:

  1. Record information about the location and the animal´s characteristics (the species, if known; the animal’s approximate size; and status (alive or dead)).
  2. Give immediate notice to the responsible authorities so that specialized help arrives as soon as possible. Report a Stranded or Injured Marine Animal.
  3. Keep at a safe distance: the animal may appear dead to the naked eye and not be. It is important to remember that cetaceans are wild animals and that in stressful situations such as strandings, they can try to defend themselves.
  4. Do not touch the animal: one of the causes of strandings is diseases; therefore, it is advisable not to contact the individuals to avoid exposure to potential pathogens.
  5. If the animal is alive, keep a distance from the animal, especially from its head and tail. Prevent children or dogs from approaching the animal.
  6. Keep calm and do not make noise that could disturb the stranded animal.
  7. Do not take the animal out of the water if it is on the shore or return it to the sea if it is on the beach: Such movement could cause serious injuries, or even death.
  8. Do not feed the animal or give it water: keep the blowhole clear because it is where they breathe.

Source: Whale Conservation Institute of Argentina

Important contacts in case of reporting a Stranded or injured Marine Mammal:

  1. National Oceanic and Atmospheric Administration
  2. Oregon Marine Mammal Stranding Network

References:

https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-unusual-mortality-events

https://www.fisheries.noaa.gov/insight/understanding-marine-mammal-unusual-mortality-events#what_criteria_define_an_ume?

https://ballenas.org.ar/programa-de-monitoreo-sanitario-ballena-franca-austral-pmsbfa/

https://globalstrandingnetwork.com/about

https://iwc.int/strandings

Proceedings of the workshop “Harmonizing Global Stranding Response.” (2020) World marine mammal Conference Barcelona, Catalonia, Spain. Editors: Gulland F and Stockin K; Ecs Special Publication Series No. 62.

Mazzariol S., Siebert U., Scheinin A., Deaville R., Brownlow A., Uhart M.., Marcondes M., Hernandez G., Stimmelmayr R., Rowles T., Moore K., Gulland F., Meyer M., Grover D., Lindsay P., Chansue N., Stockin K. (2020). Summary of Unusual Cetaceans Strandings Events worldwide (2018-2020). SC-68B/E/09 Rev1.

Fashionably late: New GEMM Lab publication measures lags between wind, upwelling, and blue whale occurrence

By Dawn Barlow, PhD Candidate, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

To understand the complex dynamics of an ecosystem, we need to examine how physical forcing drives biological response, and how organisms interact with their environment and one another. The largest animal on the planet relies on the wind. Throughout the world, blue whales feed areas where winds bring cold water to the surface and spur productivity—a process known as upwelling. In New Zealand’s South Taranaki Bight region (STB), westerly winds instigate a plume of cold, nutrient-rich waters that support aggregations of krill, and ultimately lead to foraging opportunities for blue whales. This pathway, beginning with wind input and culminating in blue whale occurrence, does not take place instantaneously, however. Along each link in this chain of events, there is some lag time.

Figure 1. A blue whale comes up for air in New Zealand’s South Taranaki Bight. Photo: L. Torres.

Our recent paper published in Scientific Reports examines the lags between wind, upwelling, and blue whale occurrence patterns. While marine ecologists have long acknowledged that lag plays a role in what drives species distribution patterns, lags are rarely measured, tested, and incorporated into studies of marine predators such as whales. Understanding lags has the potential to greatly improve our ability to predict when and where animals will be under variable environmental conditions. In our study, we used timeseries analysis to quantify lag between different metrics (wind speed, sea surface temperature, blue whale vocalizations) at different locations. While our methods are developed and implemented for the STB ecosystem, they are transferable to other upwelling systems to inform, assess, and improve predictions of marine predator distributions by incorporating lag into our understanding of dynamic marine ecosystems.

So, what did we find? It all starts with the wind. Wind instigates upwelling over an area off the northwest coast of the South Island of New Zealand called Kahurangi Shoals. This wind forcing spurs upwelling, leading to the formation of a cold water plume that propagates into the STB region, between the North and South Islands, with a lag of 1-2 weeks. Finally, we measured the density of blue whale vocalizations—sounds known as D calls, which are produced in a social context, and associated with foraging behavior—recorded at a hydrophone downstream along the upwelling plume’s path. D call density increased 3 weeks after increased wind speeds near the upwelling source. Furthermore, we looked at the lag time between wind events and aggregations in blue whale sightings. Blue whale aggregations followed wind events with a mean lag of 2.09 ± 0.43 weeks, which fits within our findings from the timeseries analysis. However, lag time between wind and whales is variable. Sometimes it takes many weeks following a wind event for an aggregation to form, other times mere days. The variability in lag can be explained by the amount of prior wind input in the system. If it has recently been windy, the water column is more likely to already be well-mixed and productive, and so whale aggregations will follow wind events with a shorter lag time than if there has been a long period without wind and the water column is stratified.

Figure 2. Top panel: Map of the study region within the South Taranaki Bight (STB) of New Zealand, with location denoted by the white rectangle on inset map in the upper right panel. All spatial sampling locations for sea surface temperature implemented in our timeseries analyses are denoted by the boxes, with the four focal boxes shown in white that represent the typical path of the upwelling plume originating off Kahurangi shoals and moving north and east into the STB. The purple triangle represents the Farewell Spit weather station where wind measurements were acquired. The location of the focal hydrophone (MARU2) where blue whale D calls were recorded is shown by the green star. (Reproduced from Barlow et al. 2021). Bottom panel: Results of the timeseries cross-correlation analyses, illustrating the lag between some of the metrics and locations examined.

This publication forms the second chapter of my PhD dissertation. However, in reality it is the culmination of a team effort. Just as whale aggregations lag wind events, publications lag years of hard work. The GEMM Lab has been studying New Zealand blue whales since Leigh first hypothesized that the STB was an undocumented foraging ground in 2013. I was fortunate enough to join the research effort in 2016, first as a Masters student and now as a PhD Candidate. I remember standing on the flying bridge of R/V Star Keys in New Zealand in 2017, when early in our field season we saw very few blue whales. Leigh and I were discussing this, with some frustration. Exclamations of “This is cold, upwelled water! Where are the whales?!” were followed by musings of “There must be a lag… It has to take some time for the whales to respond.” In summer 2019, Christina Garvey came to the GEMM Lab as an intern through the NSF Research Experience for Undergraduates program. She did an outstanding job of wrangling remote sensing and blue whale sighting data, and together we took on learning and understanding timeseries analysis to quantify lag. In a meeting with my PhD committee last spring where I presented preliminary results, Holger Klinck chimed in with “These results are interesting, but why haven’t you incorporated the acoustic data? That is a whale timeseries right there and would really add to your analysis”. Dimitri Ponirakis expertly computed the detection area of our hydrophone so we could adequately estimate the density of blue whale calls. Piecing everything together, and with advice and feedback from my PhD committee and many others, we now have a compelling and quantitative understanding of the upwelling dynamics in the STB ecosystem, and have thoroughly described the pathway from wind to whales in the region.

Figure 3. Dawn and Leigh on the flying bridge of R/V Star Keys on a windy day in New Zealand during the 2017 field season. Photo: T. Chandler.

Our findings are exciting, and perhaps even more exciting are the implications. Understanding the typical patterns that follow a wind event and how the upwelling plume propagates enables us to anticipate what will happen one, two, or up to three weeks in the future based on current conditions. These spatial and temporal lags between wind, upwelling, productivity, and blue whale foraging opportunities can be harnessed to generate informed forecasts of blue whale distribution in the region. I am thrilled to see this work in print, and equally thrilled to build on these findings to predict blue whale occurrence patterns.

Reference: Barlow, D.R., Klinck, H., Ponirakis, D., Garvey, C., Torres, L.G. Temporal and spatial lags between wind, coastal upwelling, and blue whale occurrence. Sci Rep 11, 6915 (2021). https://doi.org/10.1038/s41598-021-86403-y

Drivers of close encounters between albatross and fishing vessels

By Rachael Orben

In September of 2016, Leigh Torres, associate professor at Oregon State University, and I attended the 6th International Albatross and Petrel Conference. Somehow, amid all of the science that filled the week, Leigh first saw the Global Fishing Watch fishing map. She shouted with joy. She immediately envisioned a study to assess interactions between seabirds and fishing boats, and started considering a spatial overlap analysis between telemetry tracks of albatross with the Global Fishing Watch database. Such a study could help reduce bycatch, or the incidental catch of non-target species, like seabirds, in fisheries. Five years later, we executed that study in partnership with Global Fishing Watch, one of the first to look at fine-scale overlap between fishing vessels and marine life on the high seas (Orben et al. 2021).   

Transparent data means opportunity for analysis

Despite knowing that bycatch from fisheries is a real, significant problem for many albatross populations, we have long struggled to know where birds go, where boats fish, and where the two interact in the vast ocean, especially in largely unregulated international waters. Albatross are long-lived seabirds and 15 out of the 22 species are threatened with extinction. Scientists have been tracking albatross for three decades, but assessing individual seabird encounters with vessels has traditionally been limited by a lack of transparency in fishing activity data. Some seabirds are attracted to fishing vessels because of the bait and offal, but we don’t know the whole story of why some birds approach vessels while others don’t.

When we first put our relatively large datasets together – 9,992 days of albatross tracking data from 150 birds and Global Fishing Watch fishing effort data from 2012-2016 – we weren’t sure what we would find. The ocean is a big place, and so finding where one bird and one vessel overlap is kind of like trying to find a needle in a haystack. Would we have enough encounters between birds and boats for an analysis? Would birds encounter fishing vessels as often as we think?

Measuring encounters between albatross and vessels

After overlaying the tracking data with a gridded daily layer of fishing effort, we identified potential encounters between birds and fishing boats. We identified when an albatross could detect a vessel, at a radius or 30 kilometers, and when an albatross had a close encounter with a vessel, within a radius of 3 kilometers (following methods developed in Collet Patrick & Weimerskirch, 2015). Then, we investigated factors that influenced the occurrence and duration of close encounters, considering the bird’s behavior, environmental conditions and habitat, fishing vessel and fisheries characteristics, and temporal variables, such as time of day and month.

Species variation of encounters

We conducted our analysis for three species of albatross that forage in the north Pacific ocean, Laysan albatross, black-footed albatross, and short-tailed albatross.

  • Adult black-footed albatrosses approached vessels for a close encounter 61.9 percent of the time they detected a fishing vessel. 
  • Adult Laysan albatross had close encounters with a fishing boat 35.7 percent of the time they detected a vessel. 
  • Juvenile short-tailed albatross had a lower frequency of close encounters (28.6 percent), 

Understanding close encounters and their duration

Due to a low sample size of encounters, we were unable to investigate the reason for close encounters or their duration for black-footed albatrosses. More tracking data is critical to understand factors influencing the impact of vessels on this vulnerable species.

Laysan albatross were more likely to approach fishing vessels when fishing effort was high, but fishing boat density was low. Laysan albatross also had close encounters with vessels more frequently while they were foraging. Due to sample size, we could not further investigate the reason for the duration of encounters for this species.

Short-tailed albatrosses were also more likely to approach fishing vessels when they were searching for prey, fishing effort was high, and fishing boat density was low. They were more likely to have close encounters with vessels during the day and in habitats with water depths from 75-1500 meters. 

Vessel attendance by short-tailed albatrosses was longer when sea surface temperatures were warmer and less productive, and during periods with lower wind speeds. 

A useful approach

The information available to fisheries managers in order to reduce bycatch is most often limited to data collected from the perspective of the fishing vessels. Our analysis provides an alternative view – an albatross’ view of when and where boats are encountered in the seascape. While our analysis didn’t specifically look at bycatch, our estimates of proximity between birds and boats can be considered a proxy for  increased bycatch risk.

For the endangered short-tailed albatross, bycatch events are few, but they come with high consequences for the bird population and fishing industry. Extending our study in a dynamic ocean management framework to provide an early warning system to predict when short-tailed albatross might make close and longer encounters with fishing vessels could be the next step. Furthermore, our analysis methods to assess when, where and why marine animals interact with fishing vessels can be applied to many other marine species in order to understand and reduce conflicts with fisheries. 

This blog was for the Global Fishing Watch blog at globalfishingwatch.org

References

Collet, J., Patrick, S. C., & Weimerskirch, H. (2015). Albatrosses redirect flight towards vessels at the limit of their visual range. Marine Ecology Progress Series, 526, 199–205. http://doi.org/10.3354/meps11233

Orben, RA J Adams, M Hester, SA Shaffer, R Suryan, T Deguchi, K Ozaki, F Sato, LC Young, C Clatterbuck, MG Conners, DA Kroodsma, LG Torres. 2021. Across borders: External factors and prior behavior influence North Pacific albatross associations with fishing vessels. Journal of Applied Ecology. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.13849

Love thy mother: maternal care in cetaceans

By Lisa Hildebrand, PhD student, OSU Department of Fisheries & Wildlife, Geospatial Ecology of Marine Megafauna Lab

Last week marked the one year anniversary of the pandemic reality we have all been living. It has been an extremely challenging year, with everyone experiencing different kinds of difficulties and hurdles. One challenge that likely unites the majority of us is having to forego seeing our loved ones. For me personally, this is the longest time I have not seen my family (445 days and counting) and I know I am not alone in this situation. My homesickness started a train of thought about cetacean parental care and inspired me to write a blog about this topic. As you can see from the title, this post focuses on maternal care, rather than parental care. This bias isn’t due to my lack of research on this topic or active exclusion, but rather because there are currently no known cetacean species where paternal participation in offspring production and development extends beyond copulation (Rendell et al. 2019). Thus, this blog is all about the role of mothers in the lives of cetacean calves.

Like humans, cetacean mothers invest a lot of energy into their offspring. Most species have a gestation period of 10 or more months (Oftedal 1997). For baleen whale females in particular, pregnancy is not an easy feat given that they only feed during summer feeding seasons. They must therefore acquire all of the energy they will need for two migrations, birth, and (almost) complete lactation, before they will have access to food on feeding grounds again. For pregnant gray whales, a mere 4% loss in average energy intake on the foraging grounds will prevent her from successfully producing and/or weaning a calf (Villegas-Amtmann et al. 2015), demonstrating how crucial the foraging season is for a pregnant baleen whale. Once a calf is born, lactation ensues, ranging in length between approximately 6-8 months for most baleen whale species to upwards of one or two years in odontocetes (Oftedal 1997). The very short lactation period in baleen whales is offset by the large volume (for blue whales, up to 220 kg per day) and high fat percentage (30-50%) of milk that mothers provide for their calves (Oftedal 1997). In contrast, odontocetes (or toothed whales) have a more prolonged period of lactation with less fatty milk (10-30%). This discrepancy in lactation period lengths is in part because odontocete species do not undertake long migrations, which allows females to feed year-round and therefore allocate energy to nursing young for a longer time. 

Blue whale calf nursing in New Zealand in 2016. Footage captured via unmanned aerial system (UAS; drone) piloted by Todd Chandler for GEMM Lab’s OBSIDIAN project. Source: GEMM Lab.

Aside from the energetically costly task of lactation, cetacean mothers must also assist their calves as they learn to swim. Echelon swimming is a common position of mother-calf pairs whereby the calf is in very close proximity to its mother’s mid-lateral flank and provides calves with hydrodynamic benefits. Studies in bottlenose dolphins have shown that swimming in echelon results in a 24% reduction in mean maximum swim speeds and a 13% decrease in distance per stroke (Noren 2008) for mothers, while concurrently increasing average swim speeds and distance per stroke of calves by 28% and 19%, respectively (Noren et al. 2007). While these studies have only been conducted in odontocete species, echelon swimming is also observed in baleen whales (Smultea et al. 2017), indicating that baleen whale females may experience the same reductions in swimming efficiency. Furthermore, mothers will forgo sleep in the first days after birth (killer whales & bottlenose dolphins; Lyamin et al. 2005) and/or shorten their dive foraging times to accommodate calf diving ability (bottlenose dolphins [Miketa et al. 2018] & belugas [Heide-Jørgensen et al. 2001]). Females must endure these losses in foraging opportunities and decreased swimming efficiency when they are at their most nutritionally stressed to ensure the well-being and success of their offspring.

It is at the time of weaning (when a calf becomes independent), that we start to see differences in the maternal role between baleen and toothed whale mothers. Odontocetes have much stronger sociality than baleen whales causing offspring to stay with their mothers for much longer periods. Among the largest toothed whales, such as killer and sperm whales, offspring stay with their mothers in stable matrilineal units for often a lifetime. Among the smaller toothed whales, such as bottlenose dolphins, maternal kin maintain strong bonds in dynamic fission-fusion societies. In contrast, post-weaning maternal care in baleen whales is limited, with the mother-calf pair typically separating soon after the calf is weaned (Rendell et al. 2019). 

Conceptual diagram depicting where baleen (Mysticeti) and toothed (Odontoceti) whales fall on the continuum of low to high social structure and matrilineal kinship structure. The networks at the top depict long-term datasets of photo-identified individuals (red nodes = females, blue nodes = males, yellow nodes = calves) with thickness of connecting lines representing strength of association between individuals. Figure and caption [adapted] from Rendell et al. 2019.

The long-term impact of social bonds in odontocetes is evident through examples of vertically transmitted behaviors (from mother to calf) in a number of species. For example, the use of three unique foraging tactics (sponge carrying, rooster-tail foraging, and mill foraging) by bottlenose dolphin calves in Shark Bay, Australia, was only significantly explained by maternal use of these tactics (Sargeant & Mann 2009). In Brazil, individuals of four bottlenose dolphin populations along the coast cooperatively forage with artisanal fishermen, which involves specialized and coordinated behaviors from both species. This cooperative foraging tactic among dolphins is primarily maintained across generations via social learning from mothers to calves (Simões-Lopeset al. 2016). The risky tactic of intentional stranding by killer whales on beaches to capture elephant seal pups requires a high degree of skill and high parental investment to reduce the associated risk of stranding (Guinet & Bouvier 1995). 

Evidence for vertical transmission of specialized foraging tactics in baleen whales currently does not exist. Bubble-net feeding is a specialized tactic employed by humpback whales in three oceanic regions where multiple individuals work together to herd and trap prey (Wiley et al. 2011). However, it remains unknown whether this behavior is vertically transmitted. Simultaneous video tags from a mother-calf humpback whale pair in the Western Antarctic Peninsula documented synchrony in dives, with the calf’s track lagging behind the mother’s by 4.5 seconds, suggesting that the calf was following its mother (Tyson et al. 2012). Synchronous diving likely allows calves to observe their mothers and practice their diving, and could offer a pathway for them to mimic foraging behaviors and tactics displayed by mothers. 

While there currently may not be evidence for vertical transmission of specialized foraging tactics among the baleen whales, there is documentation of matrilineal fidelity to both foraging (Weinrich 1998, Barendse et al. 2013, Burnham & Duffus 2020) and breeding grounds (Carroll et al. 2015). Matrilineal site fidelity to foraging grounds is not exclusive to baleen whales and has also been documented in a number of odontocete species (Palsbøll et al. 1997, Turgeon et al. 2012). 

In the GEMM Lab, we are interested in exploring the potential long-term bonds, role and impact of Pacific Coast Feeding Group (PCFG) gray whale mothers on their calves. GEMM Lab PhD student Clara Bird is digging into whether specialized foraging tactics, such as bubble blasts and headstands, are passed down from mothers to calves. I hope to assess whether using the PCFG range as a foraging ground (rather than the Arctic region) is a vertically transmitted behavior or whether environmental factors may play a larger role in the recruitment and dynamics of the PCFG. It will take us a while to get to the bottom of these questions, so in the meantime hug your loved ones if it’s safe to do so or, if you’re in my boat, continue to talk to them virtually until it is safe to be reunited.

References

Barendse, J., Best, P. B., Carvalho, I., and C. Pomilla. 2013. Mother knows best: occurrence and associations of resighted humpback whales suggest maternally derived fidelity to a southern hemisphere coastal feeding ground. PloS ONE 8:e81238.

Burnham, R. E., and D. A. Duffus. 2020. Maternal behaviors of gray whales (Eschrichtius robustus) on a summer foraging site. Marine Mammal Science 36:1212-1230.

Carroll, E. L., Baker, C. S., Watson, M., Alderman, R., Bannister, J., Gaggiotti, O. E., Gröcke, D. R., Patenaude, N., and R. Harcourt. 2015. Cultural traditions across a migratory network shape the genetic structure of southern right whales around Australia and New Zealand. Scientific Reports 5:16182.

Guinet, C., and J. Bouvier. 1995. Development of intentional stranding hunting techniques in killer whale (Orcinus orca) calves at Crozet Archipelago. Canadian Journal of Zoology 73:27-33.

Heide-Jørgensen, M. P., Hammeken, N., Dietz, R., Orr, J., and P. R. Richard. 2001. Surfacing times and dive rates for narwhals and belugas. Arctic 54:207-355.

Lyamin, O., Pryaslova, J., Lance, V., and J. Siegel. 2005. Continuous activity in cetaceans after birth. Nature 435:1177.

Miketa, M. L., Patterson, E. M., Krzyszczyk, E., Foroughirad, V., and J. Mann. 2018. Calf age and sex affect maternal diving behavior in Shark Bay bottlenose dolphins. Animal Behavior 137:107-117.

Noren, S. R. 2008. Infant carrying behavior in dolphins: costly parental care in an aquatic environment. Functional Ecology 22:284-288.

Noren, S. R., Biedenbach, F., Redfern, J. V., and E. F. Edwards. 2007. Hitching a ride: the formation locomotion strategy of dolphin calves. Functional Ecology 22:278-283.

Oftedal, O. T. Lactation in whales and dolphins: evidence of divergence between baleen- and toothed-species. Journal of Mammary Gland Biology and Neoplasia 2:205-230.

Palsbøll, P. J., Heide-Jørgensen, M. P., and R. Dietz. 1996. Population structure and seasonal movements of narwhals, Monodon monoceros, determined from mtDNA analysis. Heredity 78:284-292.

Rendell, L., Cantor, M., Gero, S., Whitehead, H., and J. Mann. 2019. Causes and consequences of female centrality in cetacean societies. Philosophical Transactions of the Royal Society B 374:20180066.

Sargeant, B. L., and J. Mann. 2009. Developmental evidence for foraging traditions in wild bottlenose dolphins. Animal Behavior 78:715-721.

Simões-Lopes, P. C., Daura-Jorge, F. G., and M. Cantor. 2016. Clues of cultural transmission in cooperative foraging between artisanal fishermen and bottlenose dolphins, Tursiops truncatus (Cetacea: Delphinidae). Zoologia (Curitiba) 33:e20160107.

Smultea, M. A., Fertl, D., Bacon, C. E., Moore, M. R., James, V. R., and B. Würsig. 2017. Cetacean mother-calf behavior observed from a small aircraft off Southern California. Animal Behavior and Cognition 4:1-23.

Turgeon, J., Duchesne, P., Colbeck, G. J., Postma, L. D., and M. O. Hammill. 2011. Spatiotemporal segregation among summer stocks of beluga (Delphinapterus leucas) despite nuclear gene flow: implication for the endangered belugas in eastern Hudson Bay (Canada). Conservation Genetics 13:419-433.

Tyson, R. B., Friedlaender, A. S., Ware, C., Stimpert, A. K., and D. P. Nowacek. 2012. Synchronous mother and calf foraging behaviour in humpback whales Megaptera novaeangliae: insights from multi-sensor suction cup tags. Marine Ecology Progress Series 457:209-220.

Villegas-Amtmann, S., Schwarz, L. K., Sumich, J. L., and D. P. Costa. 2015. A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales. Ecosphere 6:1-19.

Weinrich, M. 1998. Early experience in habitat choice by humpback whales (Megaptera novaeaengliae). Journal of Mammalogy 79:163-170.

Wiley, D., Ware, C., Bocconcelli, A., Cholewiak, D., Friedlaender, A., Thompson, M., and M. Weinrich. 2011. Underwater components of humpback whale bubble-net feeding behavior. Behavior 148:575-602.

From land, sea,… and space: searching for whales in the vast ocean

By Solène Derville, Postdoc, OSU Department of Fisheries, Wildlife, and Conservation Science, Geospatial Ecology of Marine Megafauna Lab

The ocean is vast.

What I mean is that the vastness of the ocean is very hard to mentally visualize. When facing a conservation issue such as increased whale entanglement along the US West Coast (see OPAL project ), a tempting solution may  be to suggest « let’s go see where the whales are and report their location to the fishermen?! ». But, it only takes a little calculation to realize how impractical this idea is.

Let’s roll out the numbers. The US West Coast exclusive economic zone (EEZ) stretches from the coast out to 200 nautical miles offshore, as prescribed by the 1982 United Nations Convention on the Law of the Sea. It covers an area of 825,549 km² (Figure 1). Now, imagine that you wish to survey this area for marine mammals. Using a vessel such as the R/V Bell M. Shimada that is used for the Northern California Current Ecosystem surveys cruises (NCC cruises, see Dawn and Rachel’s last blog), we may detect whales at a distance of roughly 6 km (based on my preliminary results). This distance of detection depends on the height of the observer, hence the height of the flying bridge where she/he is standing (the observer’s height may also be accounted for, but unless she/he is a professional basket-ball player, I think it can be neglected here). The Shimada is quite a large ship and it’s flying bridge is 13 meters above the water. Two observers may survey the water on each side of the trackline.

Considering that the vessel is moving at 8 knots (~15 km/h), we may expect to be effectively surveying 180 km² per hour (6x2x15). That’s not too bad, right?

Again, perspective is the key. If we divide the West Coast EEZ surface by 180 km² we can estimate that it would take 2,752 hours to survey this entire region. With an average of 12 hours of daylight, this takes us to…

382 DAYS OF SURVEY, searching for marine mammals over the US West Coast. Considering that observations cannot be undertaken on days with bad weather (fog, heavy rain, strong winds…), it might take more than a year and a half to complete the survey! And what would the marine mammals have done in the meantime? Move…

This little math exercise proves that exhaustively searching for the needle in the haystack from a vessel is not the way to go if we are to describe whale distribution and help mitigate the risk of entanglement. And using another platform of observation is not necessarily the solution. The OPAL project has relied on a great collaboration with the United States Coast Guard to survey Oregon waters. The USCG helicopters travel fast compared to a vessel, about 90 knots (167 km/h). As a result, more ground is covered but the speed at which it is traveling prevents the observer from detecting whales that are very far away. Based on the last analysis I ran for the OPAL project, whales are usually detected up to 3 km from the helicopter (only 5 % of sightings exceed that distance). In addition, the helicopter generally only has capacity for one observer at a time.

If we replicate the survey time calculation from above for the USCG helicopter, we realize that even with a fast-moving aerial survey platform it would still take 137 days to cover the West Coast EEZ.

Figure 1. What is the best survey method to document marine mammal occurrence in the US West Coast Exclusive Economic zone (EEZ)?

First, we can model and extrapolate. This approach is the path we are taking with the OPAL project: we survey Oregon waters in 4 different areas along the coast each month, then model observed whale densities as a function of topographic and oceanographic variables, and then predict whale probability of presence over the entire region. These predictions are based on the assumption that our survey design effectively sampled the variety of environmental conditions experienced by whales over the study region, which it certainly did considering that all sites are surveyed year-round.

An alternative approach that has been recently discussed in the GEMM Llab, is the use of satellite images to detect whales along the coast. A communication entitled « The Potential of Satellite Imagery for Surveying Whales » was published last month in the Sensors Journal (Höschle et al., 2021) and presents the opportunities offered by this relatively new technology. The WorldView-3 satellite, owned by the company Digitalglobe and launched in 2016, has made it possible to commercialize imagery with a resolution never reached before, of the order of 30 cm per pixel. These very high resolution (VHR) satellite images make it possible to identify several species of large whales (Cubaynes et al. al., 2019) and to estimate their density (Bamford et al., 2020). Furthermore, machine learning algorithms, such as Neural Networks, have proved quite efficient at automatically detecting whales in satellite images (Guirado et al., 2019, Figure 2). While several new ultra-high resolution imaging satellites are expected to be launched in 2021 (by Maxar Technologies and Airbus), this “remote” approach looks like a promising avenue to detect whales over vast regions while drinking a cup of coffee at the office.

Figure 2. Illustration of a whale detection algorithm working on a gridded satellite image (DigitalGlobe). Source: Guirado et al., 2019.

But like any other data collection method, satellites have their drawbacks. We recently discovered that these VHR satellites are routinely switched off while passing above the ocean. Specific inquiries would need to be made to acquire data over our study areas, which would be at great expense. One of the cheapest provider I found is the Soar platform, that provides images at 50 cm resolution in partnership with the Chinese Aerospace Science and Technology Corporation. They advertise daily images anywhere on earth at $10 USD per km². This might sound cheap at first glance, but circling back to our US West Coast EEZ area calculations, we estimate that surveying this region entirely with satellite imagery would cost more than $8 million USD.

Yet, we have to look forward. The use of satellite imagery is likely to broaden and increase in the coming years, with a possible decrease in cost. Quoting Höschle et al. (2021) ‘To protect our world’s oceans, we need a global effort and we need to create opportunities for that to happen’.

Will satellites soon save whales?


References

Bamford, C. C. G. et al. A comparison of baleen whale density estimates derived from overlapping satellite imagery and a shipborne survey. Sci. Rep. 10, 1–12 (2020).

Cubaynes, H. C., Fretwell, P. T., Bamford, C., Gerrish, L. & Jackson, J. A. Whales from space: Four mysticete species described using new VHR satellite imagery. Mar. Mammal Sci. 35, 466–491 (2019).

Guirado, E., Tabik, S., Rivas, M. L., Alcaraz-Segura, D. & Herrera, F. Whale counting in satellite and aerial images with deep learning. Sci. Rep. 9, 1–12 (2019).

Höschle, C., Cubaynes, H. C., Clarke, P. J., Humphries, G. & Borowicz, A. The potential of satellite imagery for surveying whales. Sensors 21, 1–6 (2021).

Defining Behaviors

Clara Bird, PhD Student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

When I started working on my thesis, I anticipated many challenges related to studying the behavioral ecology of gray whales. From processing five-plus years of drone footage to data analysis, there has been no shortage of anticipated and unexpected issues. I recently hit an unexpected challenge when I started video processing that piqued my interest. As I’ve discussed in a previous blog, ethograms are lists of defined behaviors that help us properly and consistently collect data in a standardized approach. Ethograms form a crucial foundation of any behavior study as the behaviors defined ultimately affect what questions can be asked and what patterns are detected. Since I am working off of the thorough ethogram of Oregon gray whales from Torres et al. (2018), I had not given much thought to the process of adding behaviors to the ethogram. But, while processing the first chunk of drone videos, I noticed some behaviors that were not in the original ethogram and struggled to decide whether or not to add them. I learned that ethogram development can lead down several rabbit holes. The instinct to try and identify every movement is strong but dangerous. Every minute movement does not necessarily need to be included and it’s important to remember the ultimate goal of the analysis to avoid getting bogged down.

Fundamental behavior questions cannot be answered without ethograms. For example, Baker et al. (2017) developed an ethogram for bottlenose dolphins in Ireland in order to conduct an initial quantitative behavior analysis. They did so by reviewing published ethograms for bottlenose dolphins, consulting with multiple experts, and revising the ethogram throughout the study. They then used their data to test inter-observer variability, calculate activity budgets, and analyze how the activity budgets varied across space and time.

Howe et al. (2015) also developed an ethogram in order to conduct quantitative behavior analyses. Their goals were to use the ethogram and subsequent analyses to better understand the behavior of beluga whales in Cook Inlet, AK, USA and to inform conservation. They started by writing down all behaviors they observed in the field, then they consolidated their notes into a formal ethogram that they used and refined during subsequent field seasons. They used their data to analyze how the frequencies of different behaviors varied throughout the study area at different times. This study served as an initial analysis investigating the effect of anthropogenic disturbance and was refined in future studies.

My research is similarly geared towards understanding behavior patterns to ultimately inform conservation. The primary questions of my thesis involve individual specialization, patterns of behavior across space, the relationship between behavior and body condition, and social behavior (check out this blog to learn more). While deciding what behaviors to add to my ethogram I’ve had to remind myself of these main questions and the bigger picture. The drone footage lets us see so much detail that it’s tempting to try to define every movement we can observe. One rabbit hole I’ve had to avoid a few times is locomotion. From the footage, it is possible to document fluke beats and pectoral fin strokes. While it could be interesting to investigate how different whales move in different ways, it could easily become a complicated mess of classifying different movements and take me deep into the world of whale locomotion. Talking through what that work would look like reminded me that we cannot answer every question and trying to assess all exciting side projects can cause us to lose focus on the main questions.

While I avoided going down the locomotion rabbit hole, there were some new behaviors that I did add to my ethogram. I’ll illustrate the process with the examples of two new behaviors I recently added: fluke swish and pass under (Clips 1 and 2). Clip 1 shows a whale rapidly moving its fluke to the side. I chose to add fluke swish because it’s such a distinct movement and I’m curious to see if there’s a pattern across space, time, individual, or nearby human activity that might explain its function. Clip 2 shows a calf passing under its mom.  It’s not nursing because the calf doesn’t spend time under its mom, it just crosses underneath her. The calf pass under behavior could be a type of mom-calf tactile interaction. Analyzing how the frequency of this behavior changes over time could show how a calf’s dependency on its mom changes over as it ages.

In defining these behaviors, I had to consider how many different variations of this behavior would be included in the definition. This process involves considering at what point a variation of that behavior could serve a different function, even without knowing the function of the original behavior. For fluke swish this process involved deciding to only count a behavior as a fluke swish if it was a big, fast movement. A small and slow movement of the fluke a little to the side could serve a different function, such as turning, or be a random movement.

Clip 1: Fluke swish behavior (Video filmed under NOAA/NMFS research permit #16111​​ by certified drone pilot Todd Chandler).
Clip 2: Pass under behavior (Video filmed under NOAA/NMFS research permit #16111​​ by certified drone pilot Todd Chandler).

The next step involved deciding if the behavior would be a ‘state’ or ‘point’ event. A state event is a behavior with a start and stop moment; a point event is instantaneous and assigned to just a point in time. I would categorize a behavior as a state event if I was interested in questions about its duration. For example, I could ask “what percentage of the total observation time was spent in a certain behavior state?” A point event would be a behavior where duration is not applicable, but I could ask a question like “Did whale 1 perform more point event A than whale 2?”. Both fluke swish and pass under are point events because they only happen for an instant. In a pass under the calf is passing under its mom for just a brief point in time, making it a point event. The final step was to name the behavior. As I discussed in this blog, the name of the behavior does not matter as much as the definition but it is important that the name is clear and descriptive. We chose the name fluke swish because the fluke rapidly moves from side to side and pass under because the calf crosses under its mom.

Frankly, in the beginning, I was a bit overwhelmed by the realization that the content of my ethogram would ultimately control the questions I could answer. I could not help but worry that after processing all the videos, I would end up regretting not defining more behaviors. However, after reading some of the literature, chatting with Leigh, and reviewing the initial chunk of videos several times, I am more confidence in my judgment and my ethogram. I have accepted the fact that I can’t anticipate everything, and I am confident that the behaviors I need to answer my research questions are included. The process of reviewing and updating my ethogram has been a rewarding challenge that resulted in a valuable lesson that I will take with me for the rest of my career.

References

Baker, I., O’Brien, J., McHugh, K., & Berrow, S. (2017). An ethogram for bottlenose dolphins (Tursiops truncatus) in the Shannon Estuary, Ireland. Aquatic Mammals, 43(6), 594–613. https://doi.org/10.1578/AM.43.6.2017.594

Howe, M., Castellote, M., Garner, C., McKee, P., Small, R. J., & Hobbs, R. (2015). Beluga, Delphinapterus leucas, ethogram: A tool for cook inlet beluga conservation? Marine Fisheries Review, 77(1), 32–40. https://doi.org/10.7755/MFR.77.1.3

Torres, L. G., Nieukirk, S. L., Lemos, L., & Chandler, T. E. (2018). Drone up! Quantifying whale behavior from a new perspective improves observational capacity. Frontiers in Marine Science, 5(SEP). https://doi.org/10.3389/fmars.2018.00319

Lessons learned from (not) going to sea

By Rachel Kaplan1 and Dawn Barlow2

1PhD student, Oregon State University College of Earth, Ocean, and Atmospheric Sciences and Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

2PhD Candidate, Oregon State University Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

“Hurry up and wait.” A familiar phrase to anyone who has conducted field research. A flurry of preparations, followed by a waiting game—waiting for the weather, waiting for the right conditions, waiting for unforeseen hiccups to be resolved. We do our best to minimize unknowns and unexpected challenges, but there is always uncertainty associated with any endeavor to collect data at sea. We cannot control the whims of the ocean; only respond as best we can.

On 15 February 2021, we were scheduled to board the NOAA Ship Bell M. Shimada as marine mammal observers for the Northern California Current (NCC) ecosystem survey, a recurring research cruise that takes place several times each year. The GEMM Lab has participated in this multidisciplinary data collection effort since 2018, and we are amassing a rich dataset of marine mammal distribution in the region that is incorporated into the OPAL project. February is the middle of wintertime in the North Pacific, making survey conditions challenging. For an illustration of this, look no further than at the distribution of sightings made during the February 2018 cruise (Fig. 1), when rough sea conditions meant only a few whales were spotted.

Figure 1. (A) Map of marine mammal survey effort (gray tracklines) and baleen whale sightings recorded onboard the NOAA ship R/V Shimada during each of the NCC research cruises to-date and (B) number of individuals sighted per cruise since 2018. Note the amount of survey effort conducted in February 2018 (top left panel) compared to the very low number of whales sighted. Data summary and figures courtesy of Solene Derville.

Now, this is February 2021 and the world is still in the midst of navigating the global coronavirus pandemic that has affected every aspect of our lives. The September 2020 NCC cruise was the first NOAA fisheries cruise to set sail since the pandemic began, and all scientists and crew followed a strict shelter-in-place protocol among other COVID risk mitigation measures. Similarly, we sheltered in place in preparation for the February 2021 cruise. But here’s where the weather comes in yet again. Not only did we have to worry about winter weather at sea, but the inclement conditions across the country meant our COVID tests were delayed in transit—and we could not board the ship until everyone tested negative. By the time our results were in, the marine forecast was foreboding, and the Captain determined that the weather window for our planned return to port had closed.

So, we are still on shore. The ship never left the dock, and NCC February 2021 will go on the record as “NAs” rather than sightings of marine mammal presence or absence. So it goes. We can dedicate all our energy to studying the ocean and these spectacularly dynamic systems, but we cannot control them. It is an important and humbling reminder. But as we have continued to learn over the past year, there are always silver linings to be found.

Even though we never made it to the ship, it turns out there’s a lot you can get done onshore. Dawn has sailed on several NCC cruises before, and one of the goals this time was to train Rachel for her first stint at marine mammal survey work. This began at Dawn’s house in Newport, where we sheltered in place together for the week prior to our departure date.

We walked through the iPad program we use to enter data, looked through field guides, and talked over how to respond in different scenarios we might encounter while surveying for marine mammals at sea. We also joined Solene, a postdoc working on the OPAL project, for a Zoom meeting to edit the distance sampling protocol document. It was great training to discuss the finer points of data collection together, with respect to how that data will ultimately be worked into our species distribution models.

The February NCC cruise is famously rough, and a tough time to sight whales (Fig. 1). This low sighting rate arises from a combination of factors: baleen whales typically spend the winter months on their breeding grounds in lower latitudes so their density in Oregon waters is lower, and the notorious winter sea state makes sighting conditions difficult. Solene signed off our Zoom call with, “Go collect that high-quality absence data, girls!” It was a good reminder that not seeing whales is just as important scientifically as seeing them—though sometimes, of course, it’s not possible to even get out where you can’t see them. Furthermore, all absence data is not created equal. The quality of the absence data we can collect deteriorates along with the weather conditions. When we ultimately use these survey data to fuel species distribution models, it’s important to account for our confidence in the periods with no whale sightings.

In addition to the training we were able to conduct on land, the biggest silver lining came just from sheltering in place together. We had only met over Zoom previously, and spending this time together gave us the opportunity to get to know each other in real life and become friends. The week involved a lot of fabulous cooking, rainy walks, and an ungodly number of peanut butter cups. Even though the cruise couldn’t happen, it was such a rich week. The NCC cruises take place several times each year, and the next one is scheduled for May 2021. We’ll keep our fingers crossed for fair winds and negative COVID tests in May!

Figure 2. Dawn’s dog Quin was a great shelter in place buddy. She was not sad that the cruise was canceled.

Putting Physiological Tools to Work for Whale Conservation

By Alejandro Fernandez Ajo, PhD student at the Department of Biology, Northern Arizona University, Visiting scientist in the GEMM Lab working on the gray whale physiology and ecology project  

About four years ago, I was in Patagonia, Argentina deciding where to focus my research and contribute to whale conservation efforts. At the same time, I was doing fieldwork with the Whale Conservation Institute of Argentina at the “Whale Camp” in Península Valdés. I read tons of papers and talked with my colleagues about different opportunities and gaps in knowledge that I could tackle during my Ph.D. program. One of the questions that caught my attention was about the unknown cause (or causes) for the recurrent high calf mortalities that the Southern Right Whale (SRW) population that breeds at Peninsula Valdés experienced during the 2000s (Rowntree et al. 2013). Still, at that time, I was unsure how to tackle this research question.

Golfo San José, Península Valdés – Argentina. Collecting SRW behavioral data from the cliff’s vantage point. Source: A. Fernandez Ajo.

Between 2003 and 2013, at least 672 SRWs died, of which 91% were calves (Sironi et al. 2014). These mortalities represented an average total whale death per year of 80 individuals in the 2007-2013 period, which vastly exceeded the 8.2 average deaths per year of previous years by a ten-fold increase (i.e., 1993-2002) (Rowntree et al. 2013). In fact, this calf mortality rate was the highest ever documented for any population of large whales. During this period, from 2006 to 2009, I was the Coordinator of the Fauna Area in the Patagonian Coastal Zone Management Plan, and I collaborated with the Southern Right Whale Health Monitoring Program (AKA: The Stranding Program) that conducted field necropsies on stranded whales along the coasts of the Península and collected many different samples including whale baleen.

Southern Right Whale, found stranded in Patagonia Argentina. Source: Instituto de Conservación de Ballenas.

In this process, I learned about the emerging field of Conservation Physiology and the challenges of utilizing traditional approaches to studying physiology in large whales. Basically, the problem is that there is no possible way to obtain blood samples (the gold standard sample type for physiology) from free-swimming whales; whales are just too large! Fortunately, there are currently several alternative approaches for gathering physiological information on large whales using a variety of non-lethal and minimally invasive (or non-invasive) sample matrices, along with utilizing valuable samples recovered at necropsy (Hunt et al. 2013). That is how I learned about Dr. Kathleen Hunt’s novel research studying hormones from whale baleen (Hunt et al., 2018, 2017, 2014). Thus, I contacted Dr. Hunt and started a collaboration to apply these novel methods to understand the case of calf mortalities of the SRW calves in Patagonia utilizing the baleen samples that we recovered with the Stranding program at Península Valdés (see my previous blog post).

What is conservation physiology?

Conservation physiology is a multidisciplinary field of science that utilizes physiological concepts and tools to understand underlying mechanisms of disturbances to solve conservation problems. Conservation physiology approaches can provide sensitive biomarkers of environmental change and allow for targeted conservation strategies. The most common Conservation Physiology applications are monitoring environmental stressors, understanding disease dynamics and reproductive biology, and ultimately reducing human-wildlife conflict, among other applications.

I am now completing the last semester of my Ph.D. program. I have learned much about the amazing field of Conservation Physiology and how much more we need to know to achieve our conservation goals. I am still learning, yet I feel that through my research I have contributed to understanding how different stressors impact the health and wellbeing of whales, and about aspects of their biology that have long been obscured or unknown for these giants. One contribution I am proud of is our recent publication of, “A tale of two whales: putting physiological tools to work for North Atlantic and southern right whales,” which was published in January 2021 as a book chapter in “Conservation Physiology: Applications for Wildlife Conservation and Management” published by Oxford University Press: Oxford, UK.

This book outlines the significant avenues and advances that conservation physiology contributes to the monitoring, management, and restoration of wild animal populations. The book also defines opportunities for further growth in the field and identifies critical areas for future investigation. The text and the contributed chapters illustrate several examples of the different approaches that the conservation physiology toolbox can tackle. In our chapter, “A tale of two whales,” we discuss developments in conservation physiology research of large whales, with the focus on the North Atlantic right whale (Eubalaena glacialis) and southern right whale (Eubalaena australis), two closely related species that differ vastly in population status and conservation pressures. We review the advances in Conservation Physiology that help overcome the challenges of studying large whales via a suite of creative approaches, including photo-identification, visual health assessment, remote methods of assessing body condition, and endocrine research using non-plasma sample types such as feces, respiratory vapor, and baleen. These efforts have illuminated conservation-relevant physiological questions for both species, such as discrimination of acute from chronic stress, identification of likely causes of mortality, and monitoring causes and consequences of body condition and reproduction changes.

Book Overview:

This book provides an overview of the different applications of Conservation Physiology, outlining the significant avenues and advances by which conservation physiology contributes to the monitoring, management, and restoration of wild animal populations. By using a series of global case studies, contributors illustrate how approaches from the conservation physiology toolbox can tackle a diverse range of conservation issues, including monitoring environmental stress, predicting the impact of climate change, understanding disease dynamics, and improving captive breeding, and reducing human-wildlife conflict. The variety of taxa, biological scales, and ecosystems is highlighted to illustrate the far-reaching nature of the discipline and allow readers to appreciate the purpose, value, applicability, and status of the field of conservation physiology. This book is an accessible supplementary textbook suitable for graduate students, researchers, and practitioners in conservation science, ecophysiology, evolutionary and comparative physiology, natural resources management, ecosystem health, veterinary medicine, animal physiology, and ecology.

References

Hunt KE, Fernández Ajó A, Lowe C, Burgess EA, Buck CL. 2021. A tale of two whales: putting physiological tools to work for North Atlantic and southern right whales. In: “Conservation Physiology: Integrating Physiology Into Animal Conservation And Management”, ch. 12. Eds. Madliger CL, Franklin CE, Love OP, Cooke SJ. Oxford University press: Oxford, UK.

Sironi, M., Rowntree, V., Di Martino, M. D., Beltramino, L., Rago, V., Franco, M., and Uhart, M. (2014). Updated information for 2012-2013 on southern right whale mortalities at Península Valdés, Argentina. SC/65b/BRG/06 report presented to the International Whaling Commission Scientific Committee, Portugal. <https://iwc.int/home>.

Rowntree, V.J., Uhart, M.M., Sironi, M., Chirife, A., Di Martino, M., La Sala, L., Musmeci, L., Mohamed, N., Andrejuk, J., McAloose, D., Sala, J., Carribero, A., Rally, H., Franco, M., Adler, F., Brownell, R. Jr, Seger, J., Rowles, T., 2013. Unexplained recurring high mortality of southern right whale Eubalaena australis calves at Península Valdés, Argentina. Marine Ecology Progress Series, 493, 275-289. DOI: 10.3354/meps10506

Hunt KE, Moore MJ, Rolland RM, Kellar NM, Hall AJ, Kershaw J, Raverty SA, Davis CE, Yeates LC, Fauquier DA, et al., 2013. Overcoming the challenges of studying conservation physiology in large whales: a review of available methods. Conserv Physiol 1: cot006–cot006.

Hunt, K.E., Stimmelmayr, R., George, C., Hanns, C., Suydam, R., Brower, H., Rolland, R.M., 2014. Baleen hormones: a novel tool for retrospective assessment of stress and reproduction in bowhead whales (Balaena mysticetus). Conserv. Physiol. 2, cou030. https://doi.org/10.1093/conphys/cou030

Hunt, K.E., Lysiak, N.S., Moore, M.J., Rolland, R.M., 2016. Longitudinal progesterone profiles in baleen from female North Atlantic right whales (Eubalaena glacialis) match known calving history. Conserv. Physiol. 4, cow014. https://doi.org/10.1093/conphys/cow014

Hunt, K.E., Lysiak, N.S., Robbins, J., Moore, M.J., Seton, R.E., Torres, L., Buck, C.L., 2017. Multiple steroid and thyroid hormones detected in baleen from eight whale species. Conserv. Physiol. 5. https://doi.org/10.1093/conphys/cox061

Hunt, K.E., Lysiak, N.S.J., Matthews, C.J.D., Lowe, C., Fernández Ajó, A., Dillon, D., Willing, C., Heide-Jørgensen, M.P., Ferguson, S.H., Moore, M.J., Buck, C.L., 2018. Multi-year patterns in testosterone, cortisol and corticosterone in baleen from adult males of three whale species. Conserv. Physiol. 6, coy049. https://doi.org/10.1093/conphys/coy049