With new approaches come new insights: What we do and don’t know about blue whales

By Dawn Barlow, MSc student, Department of Fisheries and Wildlife

A few weeks ago, my labmate Dom’s blog reminded me that it is important to step back from the data and appreciate the magnificence of the animals we study from time to time. I have the privilege of studying the largest creatures on the planet. When people hear that I study blue whales, I often get a series of questions: Just how big are they, really? How many are there? Where do they migrate? Where do they breed? Despite the fact that humans hunted blue whales nearly to extinction [1,2], we still know next to nothing about these giants. The short answer to many of those questions is, “Well we don’t really know, but we’re working on it!” Which brings me back to taking time to marvel at these animals for a bit. Isn’t it remarkable that the largest animals on earth can be so mysterious?

A blue whale comes up for air in a calm sea. Photo by Leigh Torres.

Last year at this time we were aboard a research vessel in New Zealand surveying for blue whales and collecting a myriad of biological data to try and glean some insight into their lives. This winter I am processing those data and conducting a literature review to get a firm grasp on what others have found before about blue whale foraging and bioenergetics. On any given Tuesday morning Leigh and I can be found musing about the mechanics of a baleen whale jaw, about what oceanographic boundaries in the water column might be meaningful to a blue whale, about how we might quantify the energy expenditure of a foraging whale. Here are some of those musings.

Approaching a blue whale in a rigid-hull inflatable boat for data collection. UAS piloted by Todd Chandler.

Humans are, for the most part, terrestrial creatures. Even those of us that would prefer to spend most of our time near, on, or in the water are limited in what we can observe of marine life. Much of the early data that was collected on blue whales came from whaling catches. Observations of anatomy and morphology were made once the whales were killed and taken out of their marine environment. This was not long ago—Soviet whaling continued into the 1970’s in New Zealand [3]. Because baleen whales are long lived (exact age unknown for blue whales but a bowhead whale was estimated to be at least 150 years old [4]) it is entirely possible that blue whales living today remember being hunted by whalers. Observing whales in their natural state is not easy, particularly post-commercial whaling when they are few and far between.

Yet, where there is a challenge, clever people develop creative approaches and new technologies, leading to new insights. High-quality cameras have allowed scientists to photograph whales for individual identification—a valuable first step in figuring out how many there are and where they go [5]. Satellite tags have allowed scientists to track the movement of blue whales in the North Pacific and Indian Oceans, a first step in learning where these whales might go to breed. However, no blue whale breeding ground has definitively been discovered yet…

What does a whale do when it is below the surface, out of sight of our terrestrial eyes? A study from 1986 that attempted to calculate the prey demands of a whale assumed that whenever a whale was submerged, it was feeding [6]. A big assumption, but a starting place without any dive data. By 2002, tags equipped with time-depth recorders (TDR) had already revealed that blue whales make dives of variable depths and shapes [7]. But, what determines a whale’s path underwater, where they must conserve as much oxygen as they can while finding and exploiting patches of prey? The advent of digital acoustic recording tags (DTAGs) in the early 2000s have allowed scientists to measure the fine-scale movements of whales in three dimensions [8]. These tags can capture the kinematic signatures (based on pitch, roll, and yaw) of lunge-feeding events below the surface. And with the addition of echosounder technology that allows us to map the prey field, we can now link feeding events with characteristics of the prey present in the area [9]. With this progression of technology, curiosity and insight we now know that blue whales are not indiscriminate grazers, but instead pass up small patches of krill in favor of large, dense aggregations where they will get the most energetic bang for their buck.

A blue whale shows its fluke as it dives deep in an area with abundant krill deep in the water column. Photo by L. Torres.

The advent of unmanned aerial systems (UAS, a.k.a. “drones”) have provided yet another unique perspective on the lives of these whales. In 2016, our New Zealand blue whale team recorded nursing behavior between a mother and calf. In 2017, we were able to capture surface lunge feeding behavior from an aerial perspective, both for the first time.

A blue whale lunges on an aggregation of krill. UAS piloted by Todd Chandler.

Through innovative approaches, we are beginning to understand the lives of these mysterious giants. As is true for many things, the more we learn, the more questions we have. Through the GEMM Lab’s blue whale project, we have determined that a unique population of blue whales occupies the South Taranaki Bight region of New Zealand year-round; they do not simply migrate through as their current threat classification status indicates [10]. But what are their distribution patterns? Can we predict when and where whales are most likely to be in the South Taranaki Bight? Does this population have a different foraging strategy than their Californian, Chilean, or Antarctic counterparts? These are the things we are working on unraveling, and that will aid in their conservation. In the meantime, I’ll keep musing about what we don’t know, and remember to keep marveling at what we do know about the largest creatures on earth.

A blue whale mother and calf surface near Farewell Spit, New Zealand. Photo by D. Barlow.


  1. Clapham, P. J., Young, S. B. & Brownell Jr., R. L. Baleen whales: conservation issues and the status of the most endangered populations. Mamm. Rev. 29, 37–60 (1999).
  2. Branch, T. a, Matsuoka, K. & Miyashita, T. Evidence for increases in Antarctic blue whales based on baysian modelling. Mar. Mammal Sci. 20, 726–754 (2004).
  3. Branch, T. A. et al. Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean. Mammal Review 37, 116–175 (2007).
  4. George, J. C. et al. Age and growth estimates of bowhead whales (Balaena mysticetus) via aspartic acid racemization. Can. J. Zool. 77, 571–580 (1998).
  5. Sears, R. et al. Photographic identification of the Blue Whale (Balaenoptera musculus) in the Gulf of St. Lawrence, Canada. Report of the International Whaling Commission Special Issue 335–342 (1990).
  6. Kenney, R. D., Hyman, M. A. M., Owen, R. E., Scott, G. P. & Winn, H. E. Estimation of prey densities required by Western North Atlantic right whales. Mar. Mammal Sci. 2, 1–13 (1986).
  7. Acevedo-Gutierrez, A., Croll, D. A. & Tershy, B. R. High feeding costs limit dive time in the largest whales. J. Exp. Biol. 205, 1747–1753 (2002).
  8. Johnson, M. P. & Tyack, P. L. A digital acoustic recording tag for measuring the response of wild marine mammals to sound. IEEE J. Ocean. Eng. 28, 3–12 (2003).
  9. Hazen, E. L., Friedlaender, A. S. & Goldbogen, J. A. Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density. Sci. Adv. 1, e1500469–e1500469 (2015).
  10. Baker, C. S. et al. Conservation status of New Zealand marine mammals, 2013. (2016).

GEMM Lab 2017: A Year in the Life

By Dawn Barlow, MSc Student, Department of Fisheries and Wildlife

The days are growing shorter, and 2017 is drawing to a close. What a full year it has been for the GEMM Lab! Here is a recap, filled with photos, links to previous blogs, and personal highlights, best enjoyed over a cup of hot cocoa. Happy Holidays from all of us!

The New Zealand blue whale team in action aboard the R/V Star Keys. Photo by L. Torres.

Things started off with a bang in January as the New Zealand blue whale team headed to the other side of the world for another field season. Leigh, Todd and I joined forces with collaborators from Cornell University and the New Zealand Department of Conservation aboard the R/V Star Keys for the duration of the survey. What a fruitful season it was! We recorded sightings of 68 blue whales, collected biopsy and fecal samples, as well as prey and oceanographic data. The highlight came on our very last day when we were able to capture a blue whale surface lunge feeding on krill from an aerial perspective via the drone. This footage received considerable attention around the world, and now has over 3 million views!

A blue whale surfaces just off the bow of R/V Star Keys. Photo by D. Barlow.

In the spring Rachael made her way to the remote Pribilof Islands of Alaska to study the foraging ecology of red-legged kittiwakes. Her objectives included comparing the birds that reproduce successfully and those that don’t, however she was thrown a major curveball: none of the birds in the colony were able to successfully reproduce. In fact, they didn’t even build nests. Further analyses may elucidate some of the reasons for the reproductive failure of this sentinel species of the Bering Sea… stay tuned.

red-legged kittiwakes
Rachael releases a kittiwake on St. George Island. Photo by A. Fleishman.


The 2017 Port Orford field team. Photo by A. Kownacki.

Florence is a newly-minted MSc! In June, Florence successfully defended her Masters research on gray whale foraging and the impacts of vessel disturbance. She gracefully answered questions from the room packed with people, and we all couldn’t have been prouder to say “that’s my labmate!” during the post-defense celebrations. But she couldn’t leave us just yet! Florence stayed on for another season of field work on the gray whale foraging ecology project in Port Orford, this time mentoring local high school students as part of the projectFlorence’s M.Sc. defense!

Upon the gray whales’ return to the Oregon Coast for the summer, Leila, Leigh, and Todd launched right back into the stress physiology and noise project. This year, the work included prey sampling and fixed hydrophones that recorded the soundscape throughout the season. The use of drones continues to offer a unique perspective and insight into whale behavior.

Video captured under NOAA/NMFS permit #16111.


Solene with a humpback whale biopsy sample. Photo by N. Job.

Solene spent the austral winter looking for humpback whales in the Coral Sea, as she participated in several research cruises to remote seamounts and reefs around New Caledonia. This field season was full of new experiences (using moored hydrophones on Antigonia seamount, recording dive depths with SPLASH10 satellite tags) and surprises. For the first time, whales were tracked all the way from New Caledonia to the east coast of Australian. As her PhD draws to a close in the coming year, she will seek to understand the movement patterns and habitat preferences of humpback whales in the region.

A humpback whale observed during the 2017 coral sea research cruise. Photo by S. Derville.

This summer we were joined by two new lab members! Dom Kone will be studying the potential reintroduction of sea otters to the Oregon Coast as a MSc student in the Marine Resource Management program, and Alexa Kownacki will be studying population health of bottlenose dolphins in California as a PhD student in the Department of Fisheries and Wildlife. We are thrilled to have them on the GEMM Lab team, and look forward to seeing their projects develop. Speaking of new projects from this year, Leigh and Rachael have launched into some exciting research on interactions between albatrosses and fishing vessels in the North Pacific, funded by the NOAA Bycatch Reduction Engineering Program.

During the austral wintertime when most of us were all in Oregon, the New Zealand blue whale project received more and more political and media attention. Leigh was called to testify in court as part of a contentious permit application case for a seabed mine in the South Taranaki Bight. As austral winter turned to austral spring, a shift in the New Zealand government led to an initiative to designate a marine mammal sanctuary in the South Taranaki Bight, and awareness has risen about the potential impacts of seismic exploration for oil and gas reserves. These tangible applications of our research to management decisions is very gratifying and empowers us to continue our efforts.

In the fall, many of us traveled to Halifax, Nova Scotia to present our latest and greatest findings at the 22nd Biennial Conference on the Biology of Marine Mammals. The strength of the lab shone through at the meeting during each presentation, and we all beamed with pride when we said our affiliation was with the GEMM Lab at OSU. In other conference news, Rachael was awarded the runner-up for her presentation at the World Seabird Twitter Conference!

GEMM Lab members present their research. From left to right, top to bottom: Amanda Holdman, Leila Lemos, Solène Derville, Dawn Barlow, Sharon Nieukirk, and Florence Sullivan.

Leigh had a big year in many ways. Along with numerous scientific accomplishments—new publications, new students, successful fieldwork, successful defenses—she had a tremendous personal accomplishment as well. In the spring she was diagnosed with breast cancer, and after a hard fight she was pronounced cancer-free this November. We are all astounded with how gracefully and fearlessly she navigated these times. Look out world, this lab’s Principle Investigator can accomplish anything!

This austral summer we will not be making our way south to join the blue whales. However, we are keenly watching from afar as a seismic survey utilizing the largest seismic survey vessel in the world has launched in the South Taranaki Bight. This survey has been met with considerable resistance, culminating in a rally led by Greenpeace that featured a giant inflatable blue whale in front of Parliament in Wellington. We are eagerly planning our return to continue this study, but that will hopefully be the subject of a future blog.

New publications for the GEMM Lab in 2017 include six for Leigh, three for Rachael, and two for Alexa. Highlights include Classification of Animal Movement Behavior through Residence in Space and Time and A sense of scale: Foraging cetaceans’ use of scale-dependent multimodal sensory systems. Next year is bound to be a big one for GEMM Lab publications, as Amanda, Florence, Solene, Leila, Leigh, and I all have multiple papers currently in review or revision, and more in the works from all of us. How exciting!

In our final lab meeting of the year, we went around the table to share what we’ve learned this year. The responses ranged from really grasping the mechanisms of upwelling in the California Current to gaining proficiency in coding and computing, to the importance of having a supportive community in graduate school to trust that the right thing will happen. If you are reading this, thank you for your interest in our work. We are looking forward to a successful 2018. Happy holidays from the GEMM Lab!

GEMM Lab members, friends, and families gather for a holiday celebration.

The GEMM Lab is Conference-Bound!

By Dawn Barlow, MSc Student, Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

Every two years, an international community of scientists gather for one week to discuss the most current and pressing science and conservation issues surrounding marine mammals. The thousands of attendees range from longtime researchers who have truly shaped the field throughout the course of their careers to students who are just beginning to carve out a niche of their own. I was able to attend the last conference, which took place in San Francisco in 2015, as an undergraduate. The experience cemented my desire to pursue marine mammal research in graduate school and beyond, and also solidified my connection with Leigh Torres and the Geospatial Ecology of Marine Megafauna Laboratory, leading to my current enrollment at Oregon State University. This year, the 22nd Biennial Conference on the Biology of Marine Mammals takes place in Halifax, Nova Scotia, Canada. At the end of this week, Florence, Leila, Amanda, Solene, Sharon and I will head northeast to represent the GEMM Lab at the meeting!

As those of you reading this may not be able to attend, I’d like to share an overview of what we will be presenting next week. If you will be in Halifax, we warmly invite you to the following presentations. In order of appearance:

Amanda will present the final results from part of her MSc thesis on Monday in a presentation titled Comparative fine-scale harbor porpoise habitat models developed using remotely sensed and in situ data. It will be great for current GEMM Lab members to catch up with this recent GEMM Lab graduate on the other side of the continent! (Session: Conservation; Time: 4:00 pm)

On Tuesday morning, Leila will share the latest and greatest updates on her research about Oregon gray whales, including photogrammetry from drone images and stress hormones extracted from fecal samples! Her presentation is titled Combining traditional and novel techniques to link body condition and hormone variability in gray whales. This is innovative and cutting-edge work, and it is exciting to think it will be shared with the international research community. (Session: Health; Time: 10:45 am)

Did you think humpback whales have been so well studied that we must know just about everything about them? Think again! Solene will be sharing new and exciting insights from humpback whales tagged in New Caledonia, who appear to spend an intriguing amount of time around seamounts. Her talk Why do humpback whales aggregate around seamounts in South Pacific tropical waters? New insights from diving behaviour and ocean circulation analyses, will take place on Tuesday afternoon. (Session: Habitat and Distribution Speed Talks; Time: 1:30 pm)

I will be presenting the latest findings from our New Zealand blue whale research. Based on multiple data streams, we now have evidence for a unique blue whale population which is present year-round in New Zealand waters! This presentation, titled From migrant to resident: Multiple data streams point toward a resident New Zealand population of blue whales, will round out the oral presentations on Tuesday afternoon. (Session: Population Biology and Abundance; Time: 4:45 pm)

The GEMM Lab is using new technologies and innovative quantitative approaches to measure gray whale body condition and behaviors from an aerial perspective. On Wednesday afternoon, Sharon will present Drone up! Quantifying whale behavior and body condition from a new perspective on behalf of Leigh. With the emerging prevalence of drones, we are excited to introduce these quantitative applications. (Session: New Technology; Time: 11:45 am)

GoPros, kayaks, and gray whales, oh my! A limited budget couldn’t stop Florence from conducting excellent science and gaining new insights into gray whale fine-scale foraging. On Thursday afternoon, she will present Go-Pros, kayaks and gray whales: Linking fine-scale whale behavior with prey distributions on a shoestring budget, and share her findings, which she was able to pull off with minimal funds, creative study design, and a positive attitude. (Session: Foraging Ecology Speed Talks; Time: 1:55 pm)

Additional Oregon State University students presenting at the conference will include Michelle Fournet, Samara Haver, Niki Diogou, and Angie Sremba. We are thrilled to have such good representation at a meeting of this caliber! As you may know, we are all working on building the GEMM Lab’s social media presence and becoming more “twitterific”. So during the conference, please be sure to follow @GEMMLabOSU on twitter for live updates. Stay tuned!

Seabed mining permit approved in New Zealand blue whale habitat

By Dawn Barlow, MSc Student, Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

In late February, we wrapped up our 2017 blue whale survey of the South Taranaki Bight region. Upon returning to port in Wellington, Leigh and I each located our one remaining clean shirt, drank a cup of coffee, and walked into a room full of lawyers in suits where Leigh testified in front of the Environmental Protection Authority’s (EPA) Decision Making Committee. The hearing was for Trans-Tasman Resources, Ltd. (TTR)’s application for a permit to extract 50 million tons of iron sands per year from the sea floor for a 35-year period. Our reason for being there? Leigh was called as an expert witness to present our findings on blue whale distribution and ecology in the region where the proposed mining operation will be so that the potential impacts could be properly evaluated by the Decision Making Committee. Talk about seeing an immediate application of your research!

A pair of blue whales observed in February 2017 in the South Taranaki Bight.

Fast forward several months. The decision of whether or not the permit will be granted has been delayed, more evidence has been requested and considered, Leigh has testified again via skype, and the decision has been delayed yet again. It is a contentious case, and people on both sides have grown impatient, concerned, and frustrated. Finally, the date and time of the decision announcement finds me nervously refreshing my browser window until I see the outcome: the mining permit has been approved.  It was a split decision by the committee of four, with the committee chair casting the deciding vote.

A schematic of the operations of the proposed seabed mine in the South Taranaki Bight. Source: Kiwis Against Seabed Mining (kasm.org.nz).

While the Decision Making Committee was split on whether or not the permit should be approved, the constituency was not. During the hearing process, over 13,700 submissions were received, 99% of which were in opposition to the mining operation. Opposition came from Iwi (Maori tribes), commercial and recreational fishing industries, scientists, and residents of local coastal communities.

What does this mean for New Zealand, for the whales, for the ecosystem, for the future? This decision represents a landmark case that will surely set a new precedent. It is the first of its kind to be approved in New Zealand, and the first commercial scale seabed mining operation in the world. Other permit applications for seabed mines elsewhere will no doubt be submitted in the wake of the approval of TTR’s iron sands mining operation. The groups Kiwis Against Seabed Mining and Greenpeace New Zealand have announced that they will appeal the EPA’s decision in High Court, and TTR cannot begin dredging until all appeals are heard and two years of environmental monitoring have taken place.

So for the time being, life continues as usual for the blue whales. They will carry on feeding and raising their young in the South Taranaki Bight, where they already are surrounded by oil rigs, vessel traffic, and seismic airguns. In the meantime, above the water’s surface, many dedicated individuals are prepared to fight hard for environmental conservation. The blue whales will likely continue to unknowingly play a role in the decision-making process as our data demonstrate the importance of this region to their ecology, and the New Zealand public and media continue to learn about these iconic animals. The research effort I am part of has the potential to immediately and concretely influence policy decisions, and I sincerely hope that our findings will not fall on deaf ears in the appeal process. While we continue to provide biological evidence, politicians, the media, and the public need to emphasize the value of preserving biodiversity. These blue whales can be a figurehead for a more sustainable future for the region.

If you are interested in learning more, I invite you to take a minute to visit the web pages listed below.

Getting my Feet Wet: My first Dive into Marine Science

Guest Writer: Alyssa Gomez, GEMM Lab summer intern, University of Idaho, Doris Duke Conservation Scholar


Upon my arrival in Newport, OR, the sand greeted my toes, the sun my skin, and the ocean my heart. I’m an Idahoan and have yearned for the ocean my whole life, only getting glimpses of it here and there while on vacation. I have savored these memories, but for the summer of 2017, I no longer need to rely on the past. I’m only a hop, skip, and a jump away from tides and salty air until August 5th. Despite how distracting the scenery here may be, there is a lot of work to be done, as I am interning in the GEMM Lab, under the supervision of Dr. Leigh Torres, in collaboration with Craig Hayslip (Whale Telemetry Group) and Kaety Jacobson (Oregon Sea Grant).


In the short time I am here, my goal is to find out how probable it is for a gray whale (Eschrichtius robustus) to be injured to the point of scarring, and what is causing this scarring. In order to do this, I’m analyzing thousands of photos of gray whales capture in Oregon waters, which span from 2012-2016. In these thousands of images, I am identifying both anthropogenic (i.e., from fishing gear or a vessel propeller) and natural (i.e., killer whale teeth rake marks) scarring, with most focus on the anthropogenic scars. This project is collaborative, not only in terms of the data we are looking at, but in terms of who will be looking at the data. Once I’ve compiled all of the scarred whale photos, we hope to have fishermen asses the photos as well, in order to identify causes of the scars. If they believe the scars are from entanglements in fishing gear, we will ask for their opinion on the type of fishing gear that caused the scar. Hopefully, with this type of collaboration, we will be able to better understand the complex relationship between fisheries and gray whales.

Kaety Jacobson explaining the many types of gear present on vessels docked in Newport, OR.

While whale entanglement events are rare, Dungeness crab fishing gear is often involved. Dungeness crab is a very important fishery for this region, both economically and culturally, with a large commercial fleet and many recreational fishers. Dungeness crab pots are stationary on the sea floor, often placed in near shore waters and left out for many days in between drop off and pickup, and sometimes even abandoned altogether. Because gray whales, specifically the Pacific Coast Feeding Group of gray whales, feed in the same habitat as many Oregon commercial and recreational crab gear, they sometimes get entangled in the lines. Recently, there has been a great deal of discussion on this entanglement issue and how to maintain fishery profits while reducing entanglements. A working group of scientists, crab fishers, and gear experts met in Portland in March of 2017 to discuss this issue. Dr. Leigh Torres was in attendance, and thus, my project was born. Our goal is to identify the body regions most often involved, describe gear types if possible, and quantify healing rates of scars. We are hoping that this information will fill in some knowledge gaps and help us come up with effective solutions to this entanglement issue.

Kaety showing me the ins and outs of crab pots on some abandoned gear.

This seems like a big undertaking for me, as I’ve never been exposed to marine science, let alone marine mammals and all of the analysis programs, protocols, etc., that I am now using daily. There is certainly a learning curve; however, I have exactly the support and the freedom needed in order to prosper and learn in the GEMM Lab. Leigh, Florence, Dawn, Leila, and some honorary guests of this lab have been exceptionally welcoming and inviting, not to mention all others here at Hatfield.  Each day is filled with countless new opportunities, such as dock walks, necropsies, field work, meetings, and seminars.  Although I haven’t been here long, I already know that this lab is a real GEMM. I’m excited for all that is yet to come.

Leigh and I collecting a gray whale fecal sample aboard Ruby.

Finding the edge: Preliminary insights into blue whale habitat selection in New Zealand

By Dawn Barlow, MSc student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

I was fortunate enough to spend the Austral summer in the field, and so while the winter rain poured down on Oregon I found myself on the water with the sun and wind on my face, looking for blue whales in New Zealand. This spring I switched gears and spent time taking courses to build my analytical toolbox. In a course on technical writing and communication, I was challenged to present my research using only pictures and words with no written text, and to succinctly summarize the importance of my research in an introduction to a technical paper. I attended weekly seminars to learn about the diverse array of marine science being conducted at Oregon State University and beyond. I also took a course entitled “Advanced Spatial Statistics and Geographic Information Science”. In this skill-building course, we were given the opportunity to work with our own data. Even though my primary objective was to expand the tools in my toolbox, I was excited to explore preliminary results and possible insight into blue whale habitat selection in my study area, the South Taranaki Bight region (STB) of New Zealand (Figure 1).

Figure 1. A map of New Zealand, with the South Taranaki Bight (STB) region delineated by the black box. Farewell Spit is denoted by a star, and Kahurangi point is denoted by an X.

Despite the recent documentation of a foraging ground in the STB, blue whale distribution remains poorly understood in New Zealand. The STB is New Zealand’s most industrially active marine region, and the site of active oil and gas extraction and exploration, busy shipping traffic, and proposed seabed mining. This potential space-use conflict between endangered whales and industry warrants further investigation into the spatial and temporal extent of blue whale habitat in the region. One of my research objectives is to investigate the relationship between blue whales and their environment, and ultimately to build a model that can predict blue whale presence based on physical and biological oceanographic features. For this spring term, the question I asked was:

Is the number of blue whales present in an area correlated with remotely-sensed sea surface temperature and chlorophyll-a concentration?

For the purposes of this exploration, I used data from our 2017 survey of the STB. This meant importing our ship’s track and our blue whale sighting locations into ArcGIS, so that the data went from looking like this:

… to this:

The next step was to get remote-sensed images for sea surface temperature (SST) and chlorophyll-a (chl-a) concentration. I downloaded monthly averages from the NASA Moderate Resolution Imaging Spectrometer (MODIS aqua) website for the month of February 2017 at 4 km2 resolution, when our survey took place. Now, my images looked something more like this:

But, I can’t say anything reliable about the relationships between blue whales and their environment in the places we did not survey.  So next I extracted just the portions of my remote-sensed images where we conducted survey effort. Now my maps looked more like this one:

The above map shows SST along our ship’s track, and the locations where we found whales. Just looking at this plot, it seems like the blue whales were observed in both warmer and colder waters, not exclusively in one or the other. There is a productive plume of cold, upwelled water in the STB that is generated off of Kahurangi point and curves around Farewell Spit and into the bight (Figure 1). Most of the whales we saw appear to be near that plume. But how can I find the edges of this upwelled plume? Well, I can look at the amount of change in SST and chl-a across a spatial area. The places where warm and cold water meet can be found by assessing the amount of variability—the standard deviation—in the temperature of the water. In ArcGIS, I calculated the deviation in SST and chl-a concentration across the surrounding 20 km2 for each 4 km2 cell.

Now, how do I tie all of these qualitative visual assessments together to produce a quantitative result? With a statistical model! This next step gives me the opportunity to flex some other analytical muscles, and practice using another computational tool: R. I used a generalized additive model (GAM) to investigate the relationships between the number of blue whales observed in each 4 km2 cell our ship surveyed and the remote-sensed variables. The model can be written like this:

Number of blue whales ~ SST + chl-a + sd(SST) + sd(chl-a)

In other words, are SST, chl-a concentration, deviation in SST, and deviation in chl-a concentration correlated with the number of blue whales observed within each 4 km2 cell on my map?

This model found that the most important predictor was the deviation in SST. In other words, these New Zealand blue whales may be seeking the edges of the upwelling plume, honing in on places where warm and cold water meet. Thinking back on the time I spent in the field, we often saw feeding blue whales diving along lines of mixing water masses where the water column was filled with aggregations of krill, blue whale prey. Studies of marine mammals in other parts of the world have also found that eddies and oceanic fronts—edges between warm and cold water masses—are important habitat features where productivity is increased due to mixing of water masses. The same may be true for these New Zealand blue whales.

These preliminary findings emphasize the benefit of having both presence and absence data. The analysis I have presented here is certainly strengthened by having environmental measurements for locations where we did not see whales. This is comforting, considering the feelings of impatience generated by days on the water spent like this with no whales to be seen:

Moving forward, I will include the blue whale sighting data from our 2014 and 2016 surveys as well. As I think about what would make this model more robust, it would be interesting to see if the patterns become clearer when I incorporate behavior into the model—if I look at whales that are foraging and traveling separately, are the results different? I hope to explore the importance of the upwelling plume in more detail—does the distance from the edge of the upwelling plume matter? And finally, I want to adjust the spatial and temporal scales of my analysis—do patterns shift or become clearer if I don’t use monthly averages, or if I change the grid cell sizes on my maps?

I feel more confident in my growing toolbox, and look forward to improving this model in the coming months! Stay tuned.

Building scientific friendships: A reflection on the 21st annual meeting of the Northwest Student Chapter of the Society for Marine Mammalogy

By Dawn Barlow, M.Sc. student, Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

I recently had the opportunity to attend and present my research at the 21st meeting of the Northwest Student Chapter of the Society for Marine Mammalogy. This gathering represented a community of graduate and undergraduate students from the Pacific Northwest, networking and discussing their research on the biology of marine mammals. Dr. John Ford, whose name has become synonymous with killer whale research in the Pacific Northwest, delivered a compelling keynote speech on not only the history of his research, but also the history of the relationships he has built in the field and the people that have shaped the past five decades of killer whale research. This theme of cultivating scientific relationships was a thread that carried us through the weekend. Beautiful weather had us all smiling happily as we ate our lunches outside, musing about science in the sunshine. A philosopher’s café event facilitated roundtable discussions with experts in veterinary science, spatial statistics, management consulting, physiology, and marine pollution. Students were given the space to ask questions ranging from manuscript writing advice to the worth of our work in the current political climate (and write notes or doodle drawings on the paper-covered tables as we listened).

The oral and poster presentations were all very impressive. I learned that bowhead whales are likely feeding year-round in the Canadian Arctic, adjusting their dive depth to the vertical location of their copepod prey. I learned that the aerobic dive limit of stellar sea lions is more of a sliding scale rather than a switch as it is for Weddell seals. I learned that some harbor seals are estuary specialists, feeding on salmon smolt. And I learned about the importance of herring to Northeast Pacific marine mammals through an energy-based ecosystem model. I had the opportunity to present my research on the ecology of New Zealand blue whales to an audience outside of Oregon State University for the first time, and was pleased with how my presentation was received.

Aaron Purdy, MSc student with the University of British Columbia’s Marine Mammal Research Unit, moderates the first oral presentation session wearing the designated “fluke tuke”. I may have giggled at the Canadian word for beanie, but I have to admit, “fluke tuke” has a much better ring to it than “fluke beanie”!

But beyond the scientific research itself, I also learned that there is a strong community of motivated and passionate young scientists in the Pacific Northwest studying marine mammals. Our numbers may not be many and we may be scattered across several different universities and labs, but our work is compelling and valuable. At the end of the weekend, it felt like I was saying goodbye to new friends and future colleagues. And, I learned that the magnificent size of a blue whale never fails to impress and amaze, as all the conference attendees marveled over the blue whale skeleton housed in the Beaty Biodiversity Museum at the University of British Columbia.

Left to right: Michelle Fournet, Samara Haver, myself, and Niki Diogou representing Oregon State University at the student conference. Behind us is a blue whale skeleton, housed in the Beaty Biodiversity Museum on the University of British Columbia campus.

Many thanks to the graduate students from the University of British Columbia who organized such a successful event! At the end of the conference, it was decided that the next meeting of the Northwest Student Chapter will be hosted by the Oregon State University students here at Hatfield Marine Science Center in Newport. It is a year away, but I am already looking forward to seeing these newfound peers again and hearing how their research has progressed.

A happy student selfie at the end of a successful conference! We are looking forward to a reunion at Hatfield Marine Science Center next May!

New aerial footage captures blue whale lunge feeding!

By Dawn Barlow, MSc student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

This past field season the New Zealand blue whale team was lucky enough to capture something spectacular – an aerial view of a blue whale surface lunge feeding. I invite you to view the footage and listen to Leigh’s narration of the event in the video below!

Below is the full press release, written by Mark Floyd:

NEWPORT, Ore. – Blue whales didn’t become the largest animals ever to live on Earth by being dainty eaters and new video captured by scientists at Oregon State University shows just how they pick and choose their meals.

There is a reason for their discretion, researchers say. The whales are so massive – sometimes growing to the length of three school buses – that they must carefully balance the energy gained through their food intake with the energetic costs of feeding.

“Modeling studies of blue whales ‘lunge-feeding’ theorize that they will not put energy into feeding on low-reward prey patches,” said Leigh Torres, a principal investigator with the Marine Mammal Institute at Oregon State, who led the expedition studying the blue whales. “Our footage shows this theory in action. We can see the whale making choices, which is really extraordinary because aerial observations of blue whales feeding on krill are rare.”

“The whale bypasses certain krill patches – presumably because the nutritional payoff isn’t sufficient – and targets other krill patches that are more lucrative. We think this is because blue whales are so big, and stopping to lunge-feed and then speeding up again is so energy-intensive, that they try to maximize their effort.”

The video, captured in the Southern Ocean off New Zealand, shows a blue whale cruising toward a large mass of krill – roughly the size of the whale itself. The animal then turns on its side, orients toward the beginning of the krill swarm, and proceeds along its axis through the entire patch, devouring nearly the entire krill mass.

In another vignette, the same whale approaches a smaller mass of krill, which lies more perpendicular to its approach, and blasts through it without feeding.

“We had theorized that blue whales make choices like this and the video makes it clear that they do use such a strategy,” explained Torres, who works out of Oregon State’s Hatfield Marine Science Center in Newport, Oregon. “It certainly appears that the whale determined that amount of krill to be gained, and the effort it would take to consume the meal wasn’t worth the effort of slowing down.

“It would be like me driving a car and braking every 100 yards, then accelerating again. Whales need to be choosy about when to apply the brakes to feed on a patch of krill.”

The researchers analyzed the whale’s lunge-feeding and found that it approached the krill patch at about 6.7 miles per hour. The act of opening its enormous mouth to feed slowed the whale down to 1.1 mph – and getting that big body back up to cruising speed again requires a lot of energy.

The rare footage was possible through the use of small drones. The OSU team is trained to fly them over whales and was able to view blue whales from a unique perspective.

“It’s hard to get good footage from a ship,” Torres said, “and planes or helicopters can be invasive because of their noise. The drone allows us to get new angles on the whales without bothering them.”

The best field season ever

By Dawn Barlow, MSc student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

8:35pm on February 20th found the blue whale team smiling, singing, and dancing on the aft deck of the R/V Star Keys as the light faded and the sky glowed orange and we marked our final waypoint of the 2017 blue whale field season. What preceded was a series of days so near perfect that we had barely dared dream of the like. Sighting after sighting, and our team of scientists and the wonderful Star Keys crew began to work like a well-oiled machine—approach the whale gently and observe its behavior, fly the drone, deploy the CTD and echosounder, approach for photos, launch the small boat, approach for biopsy, leave the whale, re-apply sunscreen, find another whale, repeat. This series of events continued from sunrise until sunset, when the sky and water were painted brilliant colors. The sound of big blue whale breaths broke the silence over the glassy water, and the plumes of exhaled air lit up in the last bits of sunlight, lingering there without even a puff of wind to blow them away.

A blue whale mother and calf surface in front of Farewell Spit in calm conditions as the daylight starts to fade. Photo by Leigh Torres.
The small boat returns to R/V Star Keys after collecting the final biopsy sample of the season. Photo by Dawn Barlow.

Despite coming to New Zealand during the “worst summer ever”, I’m pleased to say that this has been the most fruitful field season the New Zealand blue whale project has had. We covered a total of 1,635 nautical miles and recorded sightings of 68 blue whales, in addition to sightings of killer whales, pilot whales, common dolphins, dusky dolphins, sharks, and many seabirds. Five of our blue whale sightings included calves, reiterating that the South Taranaki Bight appears to be an important area for mother-calf pairs. Callum and Mike (Department of Conservation) collected 23 blue whale biopsy samples, more than twice the number collected last year. Todd flew the drone over 35 whales, observing and documenting behaviors and collecting aerial imagery for photogrammetry. We took 9,742 photos, which will be used to determine how many unique individuals we saw and how many of them have been sighted in previous years.

A blue whale surfaces with R/V Star Keys in the background. Photo taken from the small boat by Leigh Torres.

It is always hard to see a wonderful thing come to an end, and we agreed that we would all happily continue this work for much longer if funding and weather permitted. But as the small skiff returned to the Star Keys with our final biopsy sample and the dancing began, we all agreed that we couldn’t have asked for a better note to end on. There has already been plenty of wishful chatter about future field efforts, but in the meantime we’re still floating from this year’s success. I will certainly have my hands full when I return to Oregon, and in the best possible way. It feels good to have an abundance of data from a project I’m passionate about.

A blue whale comes up for air in a calm sea. Photo by Leigh Torres.

Thank you to Western Work Boats and Captain James “Razzle-Dazzle” Dalzell, Spock, and Jason of the R/V Star Keys for their hard work, patience, and good attitudes. James made it clear at the beginning of the trip that this was to be our best year ever, and it was nothing less. The crew went from never having seen a blue whale before the trip to being experts in maneuvering around whales, oceanographic data collection, and whale poop-scooping. Thank you to Callum Lilley and Mike Ogle from the Department of Conservation for their time, impressive marksmanship, and enthusiasm. And once again thank you to all of our colleagues, funders, and supporters—this project is made possible by collaboration. Now that we’ve wrapped up, blue whale team members are heading in different directions for the time being. We’ll be dreaming of blue whales for weeks to come, and looking forward to the next time our paths cross.

Blue whale team members in front of R/V Star Keys in port in Nelson.
The team rejoices after a magnificent final survey day!


Keeping up with blue whales in a dynamic environment

By Dawn Barlow, MSc student, Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

“The marine environment is patchy and dynamic”. This is a phrase I have heard, read, and written repeatedly in my studies of marine ecology, and it has become increasingly tangible during the past several weeks of fieldwork. The presence of the blue whales we’ve come here to study is the culmination of a chain of events that begins with the wind. As we huddle up at anchor or in port while the winds blow through the South Taranaki Bight, the water gets mixed and our satellite images show blooms of little phytoplankton lifeforms. These little phytoplankton provide food for the krill, the main prey item of far larger animals—blue whales. And in this dynamic environment, nothing stays the same for long. As the winds change, aggregations of phytoplankton, krill and whales shift.

When you spend hours and hours scanning for blue whales, you also grow intimately familiar with everything that could possibly look like a blue whale but is not. Teasers include whitecaps, little clouds on the horizon, albatrosses changing flight direction, streaks on your sunglasses, and floating logs. Let me tell you, if we came here to study logs we would have quite the comprehensive dataset! We have had a few days of long hours with good weather conditions and no whales, and it is difficult not to be frustrated at those times—we came here to find whales. But the whale-less days prompt musings of what drives blue whale distribution, foraging energetics, and dreams of elaborate future studies and analyses, along with a whole lot of wishing for whales. Because, let’s admit it, presence data is just more fun to collect.

The view from the flying bridge of R/V Star Keys of Mt. Taranaki and a calm sea with no whales in sight. Photo by D. Barlow.

But we’ve also had survey days filled with so many whales that I can barely keep track of all of them. When as soon as we begin to head in the direction of one whale, we spot three more in the immediate area. Excited shouts of “UP!! Two o’clock at 300 meters!” “What are your frame numbers for your right side photos?” “Let’s come 25 degrees to port” “UUUPPP!! Off the bow!” “POOOOOOP! Grab the net!!” fill the flying bridge as the team springs into action. We’ve now spotted 40 blue whales, collected 8 biopsy samples, 8 fecal samples, flown the drone over 9 whales, and taken 4,651 photographs. And we still have more survey days ahead of us!

A blue whale surfaces just off the bow of R/V Star Keys. Photo by D. Barlow.

In Leigh’s most recent blog post she described our multi-faceted fieldwork here in the South Taranaki Bight. Having a small inflatable skiff has allowed for close approaches to the whales for photo-identification and biopsy sample collection while our larger research vessel collects important oceanographic data concurrently. I’ve been reading numerous papers linking the distribution of large marine animals such as whales with oceanographic features such as fronts, temperature, and primary productivity. In one particular sighting, the R/V Star Keys idled in the midst of a group of ~13 blue whales, and I could see foamy lines on the surface where water masses met and mixed. The whales were diving deep—flukes the size of a mid-sized car gracefully lifting out of the water. I looked at the screen of the echosounder as it pinged away, bouncing off a dense layer of krill (blue whale prey) just above the seafloor at around 100 meters water depth.  As I took in the scene from the flying bridge, I could picture these big whales diving down to that krill layer and lunge feeding, gorging themselves in these cool, productive waters. It is all mostly speculative at this point and lots of data analysis time remains, but ideas are cultivated and validated when you experience your data firsthand.

A blue whale shows its fluke as it dives deep in an area with abundant krill deep in the water column. Photo by L. Torres.

The days filled with whales make the days without whales worthwhile and valuable. To emphasize the dynamic nature of the environment we study, when we returned to an area in which we had seen heaps of whales just 12 hours before, we only found glassy smooth water and no whales whatsoever. Changing our trajectory, we came across nothing for the first half of the day and then one pair of whales after another. Some traveling, some feeding, and two mother-calf pairs.

The dynamic nature of the marine environment and the high mobility of our study species is what makes this work challenging, frustrating, exciting, and fascinating. Now we’re ready to take advantage of our next weather window to continue our survey effort and build our ever-growing dataset. I relish the wind-swept, sunburnt days of scanning and musing, and I also look forward to settling down with all of these data to try my best to compile all of the pieces of this blue whale puzzle. And I know that when I find myself behind a computer screen processing and analyzing photos, survey effort, drone footage, and oceanographic data I will be imagining the blue waters of the South Taranaki Bight, the excitement of seeing the water glow brilliantly just before a whale surfaces off our bow, and whale-filled survey days that end only when the sun sets over the water.

A big moon rises to the east and a bright oil rig on the horizon at the end of a long and fruitful survey day. Photo by L. Torres.
And to the west of the moon and the rig, the sun sets over the South Taranaki Bight. Photo by L. Torres.