Hundreds and hundreds and hundreds of models: An ecologist’s love for programming

By Dawn Barlow, PhD student, Department of Fisheries & Wildlife, Geospatial Ecology of Marine Megafauna Lab

When people hear that I study blue whales, they often ask me questions about what it’s like to be close to the largest animal on the planet, where we do fieldwork, and what data we are interested in collecting. While I love time at sea, my view on a daily basis is rarely like this:

Our small research vessel at sunset in New Zealand’s South Taranaki Bight at the end of a day of blue whale survey. Photo by D. Barlow.

More often than not, it looks something like this:

In my application letter to Dr. Leigh Torres, I wrote something along the lines of “while I relish remote fieldwork, I also find great satisfaction in the analysis process.” This statement is increasingly true for me as I grow more proficient in statistical modeling and computer programming. When excitedly telling my family about how I am trying to model relationships between oceanography, krill, whales, and satellite imagery, I was asked what I meant by “model”. Put simply, a model is a formula or equation that we can use to describe a pattern. I have been told, “all models are wrong, but some models work.” What does this mean? While we may never know exactly every pattern of whale feeding behavior, we can use the data we have to describe some of the important relationships. If our model performance is very good, then we have likely described most of what drives the patterns we see. If model performance is poor, then there is more to the pattern that we have not yet captured in either our data collection or in our analytical methods. Another common saying about models is, “A model is only ever as good as the data you put into it.” While we worked hard during field seasons to collect a myriad of data about what could be influencing blue whale distribution patterns, we inevitably could not capture everything, nor do we know everything that should be measured.

So, how do you go about finding the ‘best’ model? This question is what I’ve been grappling with over the last several weeks. My goal is to describe the patterns in the krill that drive patterns in whale distribution, the patterns in oceanography that drive patterns in the krill, and the patterns in the oceanography that drive patterns in whale distribution. The thing is, we have many metrics to describe oceanographic patterns (surface temperature, mixed layer depth, strength of the thermocline, integral of fluorescence, to name just a few), as well as several metrics to describe the krill (number of aggregations, aggregation density, depth, and thickness). When I multiplied out how many possible combinations of predictor variables and parameters we’re interested in modeling, I realized this meant running nearly 300 models in order to settle on the best ten. This is where programming comes in, I told myself, and caught my breath.

I’ve always loved languages. When I was much younger, I thought I might want to study linguistics. As a graduate student in wildlife science, the language I’ve spent the most time learning, and come to love, is the statistical programming language R. Just like any other language, R has syntax and structure. Like any other language, there are many ways in which to articulate something, to make a particular point or reach a particular end goal. Well-written code is sometimes described as “elegant”, much like a well-articulated piece of writing. While I certainly do not consider myself “fluent” in R, it is a language I love learning. I like to think that the R scripts I write are an attempt to eloquently uncover and describe ecological patterns.

Rather than running 300 models one by one, I wrote an R script to run many models at a time, and then sort the outputs by model performance. I may look at the five best models of 32 options in order to select one. But this is where Leigh reminds me to step back from the programming for a minute and put my ecologist hat back on. Insight on the part of the modeler is needed in order to discern between what are real ecological relationships and what are spurious correlations in the data. It may not be quite as simple as choosing the model with the highest explanatory power when my goal is to make ecological inferences.

So, where does this leave me? Hundreds of models later, I am still not entirely sure which ones are best, although I’ve narrowed it down considerably. My programming proficiency and confidence continue to grow, but that only goes so far in ecology. Knowledge of my study system is equally important. So my workflow lately goes something like this: write code, try to interpret model outputs, consider what I know about the oceanography of my study region, re-write code, re-interpret the revised results, and so on. Hopefully this iterative process is bringing us gradually closer to an understanding of the ecology of blue whales on a foraging ground… stay tuned.

A blue whale lunges on an aggregation of krill in New Zealand’s South Taranaki Bight. Drone piloted by Todd Chandler.

Albatrosses at sunrise, dolphins at sunset: Northern California Current cruise

By Dawn Barlow, PhD student, Geospatial Ecology of Marine Megafauna Lab, Department of Fisheries and Wildlife, Oregon State University

Sun on my face and wind in my hair, scanning the expanse of blue. Forty minutes on, twenty minutes off, from sunrise until sunset, day after day. Hours of seemingly empty blue, punctuated by graceful black-footed albatrosses wheeling and gliding over the swells, by the splashing approach of a curious group of Pacific white-sided dolphins coming to play in the bow of the ship, by whale spouts on the horizon and the occasional breaching humpback. A flurry of data entry—geographic coordinates, bearing and distance from the ship, number of animals, species identification, behavior—and then back to blue.

Scanning for marine mammals from the flying bridge of NOAA ship Bell M. Shimada. Photo: Jess O’Loughlin.

I’ve just returned from the Northern California Current (NCC) ecosystem cruise aboard NOAA ship Bell M. Shimada. My role on board was the marine mammal observer, logging marine mammal sightings during the transits between sampling stations. We surveyed and sampled between Cape Mears, Oregon and Trinidad, California, from right along the coast out to 200 nautical miles offshore. Resources in the marine environment are patchy, and our coastline is highly productive. This diversity in environmental conditions creates niche habitats for many species, which is one reason why surveying and sampling across a broad geographic range can be so informative. We left Newport surrounded by gray whales, feeding in green, chilly waters at temperatures around 12°C. Moving west, the marine mammal and seabird sightings were increasingly sparse, the water increasingly blue, and the surface temperature warmed to a balmy 17°C. We had reached offshore waters, an ocean region sometimes referred to as the “blue desert”. For an entire day I didn’t see a single marine mammal and only just a few seabirds, until a handful of common dolphins—more frequently seen in warm-temperate and tropical waters to the south—joined the ship at sunset. As we transited back inshore over the productive Heceta Bank, the water became cooler and greener. I stayed busy logging sightings of humpback and gray whales, harbor porpoise and Dall’s porpoise, pacific white-sided dolphins and sea lions. These far-ranging marine predators must find a way to make a living in the patchy and dynamic ocean environment, and therefore their distribution is also patchy—aggregated around areas of high productivity and prey availability, and occasionally seen transiting in between.

Here are a few cruise highlights:

Curious groups of common dolphins (Delphinus delphis) came to play in the bow wake of the ship and even checked out the plankton nets when they were deployed. Common dolphins are typically found further south, however we saw several groups of them in the warmer waters far offshore.

Ocean sunfish (Mola mola) will occasionally lay themselves flat at the surface so that seabirds will pick them clean of any parasites. I was delighted to observe this for the first time just off Newport! There were several more sunfish sightings throughout the cruise.

Gull picking parasites off an ocean sunfish (Mola mola). Photo: Dawn Barlow.

A masked booby (Sula dactylatra) hung around the ship for a bit, 16 nautical miles from shore, just south of the Oregon-California border. Considered a tropical species, a sighting this far north is extremely rare. While masked boobies are typically distributed in the Caribbean and tropical Pacific from Mexico to Australia, one found its way to the Columbia River in 2006 (first record in the state of Oregon) and another showed up here to Newport in 2015 – reportedly only the second to be recorded north of Mendocino County, California. Perhaps this sighting is the third?

Masked booby (Sula dactylatra). Photo: Dawn Barlow.

While most of my boat-based fieldwork experiences have been focused on marine mammal research, this was an interdisciplinary cruise aimed at studying multiple aspects of the northern California current ecosystem. There were researchers on board studying oceanography, phytoplankton and harmful algal blooms, zooplankton, and microplastics. When a group of enthusiastic scientists with different areas of expertise come together and spend long days at sea, there is a wonderful opportunity to learn from one another. The hydroacoustic backscatter on the scientific echosounder prompted a group discussion about vertical migration of plankton one evening. Another evening I learned about differences in energetic content between krill species, and together we mused about what that might mean for marine predators. This is how collaborations are born, and I am grateful for the scientific musings with so many insightful people.

Thank you to the Shimada crew and the NCC science team for a wonderful cruise!

The NCC science team after a successful cruise!

Cloudy with a chance of blue whales

By Dawn Barlow, PhD student, Department of Fisheries & Wildlife, Geospatial Ecology of Marine Megafauna Lab

As a PhD student studying the ecology of blue whales in New Zealand, my time is occupied by questions such as: When and where are the blue whales? Can we predict where they will be based on environmental conditions? How does their distribution overlap with human activity such as oil and gas exploration?

Leigh and I have just returned from New Zealand, where I gave an oral presentation at the Society for Conservation Biology Oceania Congress entitled “Cloudy with a chance of whales: Forecasting blue whale presence to mitigate industrial impacts based on tiered, bottom-up models”. While the findings I presented are preliminary, an exciting ecological story is emerging, and one with clear management implications.

The South Taranaki Bight (STB) region of New Zealand is an important area for a population of blue whales which are unique to New Zealand. A wind-driven upwelling system brings cold, productive waters into the bight [1], which sustains high densities of krill [2], blue whale prey. The region is also frequented by busy shipping traffic, oil and gas drilling and extraction platforms as well as seismic survey effort for subsurface oil and gas reserves, and is the site of a recently-permitted seabed mine for iron sands (Fig. 1). However, a lack of knowledge on blue whale distribution and habitat use patterns has impeded effective management of these potential anthropogenic threats.

Figure 1. A blue whale surfaces in front of a floating production storage and offloading vessel servicing the oil rigs in the South Taranaki Bight. Photo by D. Barlow.

Three surveys were conducted in the STB region in the summer months of 2014, 2016, and 2017. During that time, we not only looked for blue whales, we also collected oceanographic data and hydroacoustic backscatter data to map and measure aspects of the krill in the region. These data streams will help us understand the functional, ecological relationships between the environment (oceanography), prey (krill), and predators (blue whales) in the ecosystem (Fig. 2). But in practice these data are costly and time-consuming to collect, while other data sources such as satellite imagery are readily accessible to managers at a variety of spatial and temporal scales. Therefore, another one of my aims is to link the data we collected in the field to satellite imagery, so that managers can have a practical tool to predict when and where the blue whales are most likely to be found in the region.

Figure 2. Data streams collected during surveys of the South Taranaki Bight Region in 2014, 2016, and 2017. 

So what did I find? Here are the highlights from my preliminary analyses:

  • The majority of the patterns in blue whale distribution can be explained by the density, depth, and thickness of the krill patches.
  • Patterns in the krill are driven by oceanography.
  • Those same oceanographic parameters that drive the krill can be used to explain blue whale distribution.
  • There are tight relationships between the important oceanographic variables and satellite images of sea surface temperature.
  • Blue whale distribution can, to some degree, be explained using just satellite imagery.

We were able to identify a sea surface temperature range in the satellite imagery of approximately 18°C where the likelihood of finding a blue whale is the highest. Is this because blue whales really like 18° water? Well, more likely this relationship exists because the satellite imagery is reflective of the oceanography, and the oceanography drives patterns in the krill distribution, and the krill drives the distribution of blue whales (Fig. 3). We were able to make each of these functional linkages through our series of models, which is quite exciting.

Figure 3. The tiered modeling approach we took to investigate the ecological relationships between blue whales, krill, oceanography, and satellite imagery. Because of the ecological linkages we made, we are able to say that any relationship between whale distribution and satellite imagery most likely reflects a relationship between the blue whales and their prey. 

That’s all well and good, but we were interested in testing these relationships to see if our identified habitat associations hold up even when we do not have field data (oceanographic, krill, and whale data). This past austral summer, we did not have a field season to collect data, but there was a large seismic airgun survey of the STB region. Seismic survey vessels are required to have trained marine mammal observers on board, and we were given access to the blue whale sightings data they recorded during the survey. In December, when the water was right around the preferred temperature identified by our models (18°C), the observers made 52 blue whale sightings (Fig. 4). In January and February, the waters warmed and only two sightings were made in each month. This is not only reassuring because it supports our model results, it also implies that there is the potential to balance industrial use of the area with protection of blue whale habitat, based on our understanding of the ecology. In January and February, very few blue whales were likely disturbed by the industrial activity in the STB, as conditions were not favorable for foraging at the location of the seismic survey. In contrast, the blue whales that were in the STB region in December may have experienced physiological consequences of sustained exposure to airgun noise since the conditions were favorable for foraging in the STB. In other words, the whales may have tolerated the noise exposure to gain access to good food, but this could have significant biological repercussions such as increased stress [3].

Figure 4. Monthly sea surface temperature (MODIS Aqua) overlaid with blue whale sightings from marine mammal observers aboard seismic survey vessel R/V Amazon Warrior. Black rectangles represent areas of seismic survey effort. Blue whale sighting location data were provided by RPS Energy Pty Ltd & Schlumberger, and Todd Energy.

In the first two weeks of July, we presented these latest findings to managers at the New Zealand Department of Conservation, the Minister of Conservation, the CEO and Policy Advisor of a major oil and gas conglomerate, NGOs, advocacy groups, and scientific colleagues. It was valuable to gather feedback from many different stakeholders, and satisfying to see such a clear interest in, and management application of, our work.

Dr. Leigh Torres and Dawn Barlow in front of Parliament in Wellington, New Zealand, following the presentation of their recent findings.

What’s next? We’re back in Oregon, and diving back into analysis. We intend to take the modeling work a step further to make the models predictive—for example, can we forecast where the blue whales will be based on the temperature, productivity, and winds two weeks prior? I am excited to see where these next steps lead!

References:

  1. Shirtcliffe TGL, Moore MI, Cole AG, Viner AB, Baldwin R, Chapman B. 1990 Dynamics of the Cape Farewell upwelling plume, New Zealand. New Zeal. J. Mar. Freshw. Res. 24, 555–568. (doi:10.1080/00288330.1990.9516446)
  2. Bradford-Grieve JM, Murdoch RC, Chapman BE. 1993 Composition of macrozooplankton assemblages associated with the formation and decay of pulses within an upwelling plume in greater cook strait, New Zealand. New Zeal. J. Mar. Freshw. Res. 27, 1–22. (doi:10.1080/00288330.1993.9516541)
  3. Rolland RM, Parks SE, Hunt KE, Castellote M, Corkeron PJ, Nowacek DP, Wasser SK, Kraus SD. 2012 Evidence that ship noise increases stress in right whales. Proc. Biol. Sci. 279, 2363–8. (doi:10.1098/rspb.2011.2429)

“Applied conservation science”

By Dawn Barlow, M.S.
Ph.D. student, Department of Fisheries and Wildlife, Oregon State University

For years, I have said I want to do “applied conservation science”. As an undergraduate student at Pitzer College I was a double major in Biology and Environmental Policy. While I have known that I wanted to study the oceans on some level my whole life, and I have known for about a decade that I wanted to be a scientist, I realized in college that I wanted to learn how science could be a tool for effective conservation of the marine ecosystems that fascinate me.

Answering questions during my public defense seminar. Photo by Leila Lemos.

Just over a week ago, I successfully defended my MS thesis. When Leigh introduced me at the public seminar, she read a line from my initial letter to her expressing my interest in being her graduate student: “My passion for cetacean research lies not only in fascination of the animals but also how to translate our knowledge of their biology and ecological roles into effective conservation and management measures.” I believe I’ve grown and learned a lot in the two and a half years since I crafted that email and nervously hit send, but the statement is still true.

My graduate research in many ways epitomizes what I am passionate about. I am part of a team studying the ecology of blue whales in a highly industrial area of New Zealand. Not only is it a system in which we can address fascinating questions in ecology, it is also a region that experiences extensive pressure from human use and so all of our findings have direct management implications.

We recently published a paper documenting and describing this New Zealand blue whale population, and the findings reached audiences and news outlets far and wide. Leigh and I are headed to New Zealand for the first two weeks in July. During this time we will not only present our latest findings at the Society for Conservation Biology Oceania Conference, we will also meet with managers at the New Zealand Department of Conservation, speak with the Minister of Energy and Resources as well as the Minster of Conservation, meet with the CEO and Policy Advisor of PEPANZ (a representative group of oil and gas companies in New Zealand), and participate in a symposium of scientists and stakeholders aiming to establish goals for the protection of whales in New Zealand. Now, “applied conservation science” extends well beyond a section in the discussion of a paper outlining the implications of the findings for management.

A blue whale surfaces in front of a floating production storage and offloading (FPSO) vessel servicing the oil rigs in the South Taranaki Bight. Photo by Dawn Barlow. 

During our 2017 field season in New Zealand, Leigh and I found ourselves musing on the flying bridge of the research vessel about all the research questions still to be asked of this study system and these blue whales. How do they forage? What are their energetic demands? How does disturbance from oil and gas exploration impact their foraging and their energetic demands? Leigh smiled and told me, “You better watch out, or this will turn into your PhD.” I said that maybe it should. Now I am thrilled to immerse myself into the next phase of this research project and the next chapter of my academic journey as a PhD student. This work is applied conservation science, and I am a conservation biologist. Here’s to retaining my passion for ecology and fascination with my study system, while not losing sight of the implications and applications of my work for conservation. I am excited for what is to come!

Dawn Barlow and Dr. Leigh Torres aboard the R/V Star Keys during the 2017 blue whale field season in New Zealand. Photo by Todd Chandler.

Forecasting blue whale presence: Small steps toward big goals

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

In 2013, Leigh first published a hypothesis that the South Taranaki Bight region between New Zealand’s North and South Islands is important habitat for blue whales  (Torres 2013). Since then, we have collected three years of data and conducted dedicated analyses, so we now understand that a unique population of blue whales is found in New Zealand, and that they are present in the South Taranaki Bight year-round (Barlow et al. in press).

A blue whale surfaces in the South Taranaki Bight. Photo by Leigh Torres.

This research has garnered quite a bit of political and media attention. A major platform item for the New Zealand Green Party around the last election was the establishment of a marine mammal sanctuary in the South Taranaki Bight. When the world’s largest seismic survey vessel began surveying the South Taranaki Bight this summer for more oil and gas reserves using tremendously loud airguns, there were rallies on the lawn in front of Parliament featuring a large inflatable blue whale that the protesters affectionately refer to as “Janet”. Needless to say, blue whales have made their way into the spotlight in New Zealand.

Janet the inflatable blue whale accompanies protesters on the lawn in front of Parliament in Wellington, New Zealand. Image credit: Greenpeace.

Now that we know there is a unique population of blue whales in New Zealand, what is next? What’s next for me is an exciting combination of both ecology and conservation. If an effective sanctuary is to be implemented, it needs to be more than a simple box drawn on a map to check off a political agenda item—the sanctuary should be informed by our best ecological knowledge of the blue whales and their habitat.

In July, Leigh and I will attend the Society for Conservation Biology meeting in Wellington, New Zealand, and I’ll be giving a presentation titled “Cloudy with a chance of whales: Forecasting blue whale presence based on tiered, bottom-up models”. I’ll be the first to admit, I am not yet forecasting blue whale presence. But I am working my way there, step-by-step, through this tiered, bottom-up approach. In cetacean habitat modeling, we often assume that whale distribution on a foraging ground is determined by their prey’s distribution, and that satellite images of temperature and chlorophyll-a provide an accurate picture of what is going on below the surface. Is this true? With our three years of data including in situ oceanography, krill hydroacoustics, and blue whale distribution and behavior, we are in a unique position to test some of those assumptions, as well as provide managers with an informed management tool to predict blue whale distribution.

What questions will we ask using our data? Firstly, can in situ oceanography (i.e., thermocline depth and temperature, mixed layer depth) predict the distribution and density of blue whale prey (krill)? Then, can those prey patterns be accurately predicted in the absence of oceanographic measurements, using just satellite images? Next, we’ll bring the blue whales back into the picture to ask: can we predict blue whale distribution based on our in situ measurements of oceanography and prey? And finally, in the absence of in situ measurements (which is most often the case), can we forecast where the whales will be based just on remotely-sensed images of the region?

The transducer pole in the water off the RV Star Keys (left) deployed with the echosounder to collect prey availability data, including this image (right) of krill swarms near feeding blue whales. Photo by Leigh Torres.

So, cloudy with a chance of whales? Well, you’ll have to stay tuned for that story in the coming months. In the meantime, I can tell you that as daunting as it is to aggregate so many data streams, each step of the way has a piece of the story to tell. I can’t wait to see how it falls together, both from an ecological modeling perspective and a conservation management objective.

A blue whale surfaces in front of a floating production storage and offloading (FPSO) vessel which services the oil rigs in the South Taranaki Bight. Photo by Dawn Barlow.

 

References:

Torres, L. G. (2013). Evidence for an unrecognised blue whale foraging ground in New Zealand. New Zealand Journal of Marine and Freshwater Research47(2), 235-248.

Barlow, D. R., Torres, L. G., Hodge, K. B., Steel, D. Baker, C. S., Chandler, T. E., Bott, N., Constantine, R., Double, M. C., Gill, P., Glasgow, D., Hamner, R. M., Lilley, C., Ogle, M., Olson, P. A., Peters, C., Stockin, K. A., Tessaglia-Hymes, C. T., Klinck, H. (in press). Documentation of a New Zealand blue whale population based on multiple lines of evidence. Endangered Species Research. 

There is no such thing as “throwing it away”: Why I try to reduce my plastic consumption

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

Several years ago, I had a profound experience on a remote little coral island in the Kingdom of Tonga, in the middle of the South Pacific. I was a crew member aboard a 46’ sailboat, traveling in Tonga and Fiji. This trip was a time when I became very aware of my consumption because when living on a boat, you carry your waste with you. The South Pacific is a region of little islands scattered across wide ocean spaces, and my eyes were opened to island culture. An island is analogous to a large boat—your waste cannot go far. The idea of “throwing it away” began to seem suspect. Does anything really “go away”?

A seemingly pristine beach on Tungua Island, Kingdom of Tonga. Upon closer inspection, we realized the volume of plastics that could be found even on an island this remote. Photo by D. Barlow.

After spending a night at anchor in the Kingdom of Tonga when I listened through the hull to signing humpback whales and felt their deep tones vibrate our mast, I thought I was in a place as pure and untouched as I would ever experience. The next morning, we ventured to shore on an island that we could circumnavigate in less than an hour on foot. But the soft sand was strewn with more than just conch and cowrie shells. It was also strewn with plastic. I began to pick up the trash items on the beach, and before long I had a large bag filled to the brim with plastic. The captain humored me when I wanted to bring it back to the boat. But what was I going to do with it then? These remote island places have very little infrastructure—they can’t recycle it there. So should I take it to another island where it would likely get barged out and dumped back in the ocean? Or a landfill? What struck me most was the realization that none of these products were manufactured on these islands. Some of this plastic may have been imported to the nearest island with a town or city, while some likely had drifted across the sea to this landing spot. All the plastics that I picked up on that one, small island were just a tiny portion of ocean plastic that wash ashore on the world’s beaches, a tiny glimpse of a much larger issue.

Eight million tons of plastics make their way into the oceans each year. Let that number sink in. There is no such thing as “throwing it away”, because “away” does not exist. “Away” is the ocean.

“What lies under”. Image credit: Ferdi Rizkiyanto.

Before sitting down to write this, I participated in a beach cleanup event here in my local community in Newport, Oregon. Today along the whole Oregon Coast, over 3,000 volunteers removed more than 15,000 pounds of litter and marine debris from the coastal places they love. A few weeks ago Surfrider Foundation screened the documentary Straw, directed by Linda Booker. Following the well-attended screening, a panel of community members from Surfrider, the Oregon Coast Aquarium, and Thomson Sanitary Services answered questions from the audience. In a lively discussion, we learned about why China is no longer accepting our recyclables and consequently we can only recycle plastics #1 and #2 here in Oregon, about how marine animals are rehabilitated after becoming entangled in plastic waste, about how Surfrider is encouraging local businesses to switch to paper straws and only offer them by request. As daunting as it is to think about the scale of our plastic consumption and the damage it causes, I am encouraged by the engagement and bottom-up movement in my community.

My life is shaped by the ocean—it is my inspiration, my work, my passion, my place of adventure and joy, the place that humbles me and heals me. Imagining the relationship between the products I use and the ocean is what makes me think twice before consuming. If I am driving in my car and want to stop for coffee but don’t have a reusable mug with me, I consider “if I were on a boat, would I drink coffee out of a single-use cup and then throw it away, toss it over the rail?” Of course not. So I invite you to think about the plastic in your life—it is everywhere. Think about how that plastic relates to what you love. Will it make its way into the stomach of a baby albatross, a sea turtle, the filter-feeding shellfish and large predatory fish that you love to eat?

Lifestyle changes can be simple and impactful. As a consumer, use your purchase power—when you have the option to buy a product wrapped in plastic or one that is not, opt for no plastic. Show manufacturers what you value. Bring reusable bags to the grocery store. Use waxed paper instead of plastic saran wrap. Talk to others, share your choices with them, encourage them to minimize their plastic use. And if you need context or motivation, imagine the relationship between the products you consume and the places that you love.

 

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.

References:

  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.