By Dawn Barlow, MSc Student, Department of Fisheries and Wildlife, Oregon State University
The year is rapidly coming to a close, and what a busy year it has been in the Geospatial Ecology of Marine Megafauna Lab! In 2016, our members have traveled to six continents for work (all seven if we can carry Rachael’s South African conference over from the end of 2015…), led field seasons in polar, temperate, and tropical waters, presented at international conferences, processed and analyzed data, and published results. Now winter finds us holed up in our offices in Newport, and various projects are ramping up and winding down. With all of the recent turmoil 2016 has brought, it is a nice to reflect on the good work that was accomplished over the last 12 months. In writing this, I am reminded of how grateful I am to work with this talented group of people!
The year started with a flurry of field activity from our southern hemisphere projects! Erin spent her second season on the Antarctic peninsula, where she contributed to the Palmer Station Long Term Ecological Research Project.
Erin in action collecting a crabeater seal scat sample along the West Antarctic Peninsula.
Aerial image of the research vessel and a pair of blue whales during the 2016 New Zealand survey.
The New Zealand blue whale project launched a comprehensive field effort in January and February, and it was a fruitful season to say the least. The team deployed hydrophones, collected tissue biopsy and fecal samples, and observed whales feeding, racing and nursing. The data collected by the blue whale team is currently being analyzed to aid in conservation efforts of these endangered animals living in the constant presence of the oil and gas industry.
Midway atoll is home to one of the largest albatross colony in the world, and Rachael visited during the winter breeding season. In addition to deploying tracking devices to study flight heights and potential conflict with wind energy development, she became acutely aware of the hazards facing these birds, including egg predation by mice and the consumption of plastic debris.
Laysan albatross equipped with a GPS data logger.Fledgling from last year with a stomach full of plastic.
Early summertime brought red-legged kittiwakes to the remote Pribilof Islands in Alaska to nest, and Rachael met them there to study their physiology and behavior.
Rachael with a noosepole on St. George Island, AlaskaSolene with Dr. Claire Garrigue during fieldwork at the Chesterfield Reefs, New Caledonia.
As the weather warmed for us in the northern hemisphere, Solene spent the austral winter with the humpback whales on their breeding grounds in New Caledonia. Her team traveled to the Chesterfield Reefs, where they collected tissue biopsy samples and photo-IDs, and recorded the whale’s songs. But Solene studies far more than just these whales! She is thoroughly examining every piece of environmental, physical, and oceanographic data she can get her hands on in an effort to build a thorough model of humpback whale distribution and habitat use.
A humpback whale in New Caledonia’s South Lagoon.
Summertime came to Oregon, and the gray whales returned to these coastal waters. Leigh, Leila, and Todd launched into fieldwork on the gray whale stress physiology project. The poop-scooping, drone-flying team has gotten a fair bit of press recently, follow this link to listen to more!
The overhead drone captures a pair of gray whales surfacing between kelp beds off Cape Blanco, Oregon, with the research vessel nearby. Take under NOAA/NMFS permit #16111 given to John Calambokidis.
And while Leigh, Leila, and Todd followed the grays from the water, Florence and her team watched them from shore in Port Orford, tracking their movement and behavior. In an effort to gain a better understanding of the foraging ecology of these whales, Florence and crew also sampled their mysid prey from a trusty research kayak.
Florence and the summer 2016 gray whale field team.Kelli Iddings sampling mysid near Port Orford.
With the influx of gray whales came an influx of new and visiting GEMM Lab members, as Florence’s team of interns joined for the summer season. I was lucky enough to join this group as the lab’s newest graduate student!
All of the summer 2016 GEMM Lab members.
Our members have presented their work to audiences far and wide. This summer Leigh, Amanda, and Florence attended the International Marine Conservation Congress, and Amanda was awarded runner-up for the best student presentation award! Erin traveled to Malaysia for the Scientific Convention on Antarctic Research, and Rachael and Leigh presented at the International Albatross and Petrel Conference in Barcelona. With assistance from Florence and Amanda, Leigh led an offshore expedition on OSU’s research vessel R/V Oceanus to teach high school students and teachers about the marine environment.
Amanda with her award!Science Party musters in the dry lab for safety debrief aboard R/V Oceanus.
Wintertime in Newport has us tucked away indoors with our computers, cranking through analyses and writing, and dreaming about boats, islands, seabirds, and whales… Solene visited from the South Pacific this fall, and graced us with her presence and her coding expertise. It is a wonderful thing to have labmates to share ideas, frustrations, and accomplishments with.
Solving a coding problem together on a wintery evening.
As the year comes to a close, we have two newly-minted Masters of Science! Congratulations to Amanda and Erin on successfully defending their theses, and stay tuned for their upcoming publications!
The season has shifted since the post I wrote this summer about diving into the world of New Zealand blue whales and the beginnings of my masters research. My fieldwork will take place during the upcoming austral summer, which will require me to miss the winter term here on campus. This quarter, I have put my research on the back burner for the time being in favor of a full load of coursework. But my project is still there, simmering subtly and persistently, and giving relevance to the coursework that I’m focusing my energy on this fall term.
As an undergraduate student, I acquired a broad scientific background and had the opportunity to dabble in the areas of biology that piqued my interest. I arrived here with a basic understanding of chemistry, physics, cell biology, anatomy, marine ecology and conservation biology. I gained experience working in the field with intertidal sea stars, snails, mussels, crabs and barnacles, with bottlenose dolphins and with humpback whales. But now my focus has narrowed as I’ve honed in on the specific questions that I will pursue over the next two years. My passion lies in marine ecology and conservation. Now, as a graduate student studying the ecology of a little-known population in a highly industrial area, this passion can come to fruition. For my masters, I hope to do the following:
A) Use photo-identification analysis to obtain a population abundance estimate for blue whales in New Zealand
B) Investigate blue whale residency and distribution patterns in New Zealand waters
C) Develop a comprehensive blue whale habitat use model for the South Taranaki Bight region of New Zealand, which incorporates physical and biological data
Down the road I hope to have implemented a capture-recapture abundance estimate model that best fits the dynamics of this population of blue whales, to have mapped where sightings have occurred and where the highest densities of blue whales are found in both space and time, and to have paired blue whale presence and absence with prey distribution, remote-sensed environmental data, and in situ oceanographic data. But how does one accomplish these things? I need a toolbox to draw from. And so this fall, I am assembling my toolbox, learning programs and analytical skills. I am taking methods courses—statistics, data management in R, analysis in GIS, methods in physiology and behavior of marine megafauna—that are no longer explorations into the world of natural science, but rather tools for exploring, identifying, and interpreting specific phenomena in ecology. While each comes with its own hiccups and headaches (see Florence’s post about this…), they are powerful tools.
Aside from coursework, the research I’m conducting has gained weight and relevance beyond being an investigation in ecology. My study area lies in the South Taranaki Bight of New Zealand, which is a contentious proposed seabed mining site for iron sands. As an undergraduate student I read case studies and wrote papers on the environmental impacts of industry, and I decided to go graduate school because I want to do research that has direct conservation applications. Last week I compiled all the data I’ve processed on blue whale sightings, seasonal residency, and photo identification for the South Taranaki Bight, which will be included as evidence submitted in environmental court in New Zealand by my advisor, Dr. Leigh Torres. “Applied conservation science” has been an abstract idea that has excited and motivated me for a long time, and now I am partaking in this process, experiencing applied conservation science firsthand.
And so my toolbox is growing, and the scope of my work is simultaneously narrowing in focus and expanding in relevance. The more tools I acquire, the more excited I am to apply them to my research. As I build my toolbox this fall, this process is something I look forward to enhancing while I’m in the field, when I dig deeper into data analysis, and as I grow as a conservation scientist.
A blue whale dives in the South Taranaki Bight, New Zealand. Photo by Leigh Torres.
Our third day aboard the Oceanus began in the misty morning fog before the sun even rose. We took the first CTD cast of the day at 0630am because the physical properties of the water column do not change much with the arrival of daylight. Our ability to visually detect marine mammals, however, is vastly improved with a little sunlight, and we wanted to make the best use of our hours at sea possible.
Randall Munroe www.XKCD.com
Our focus on day three was the Astoria canyon – a submarine feature just off the Oregon and Washington coast. Our first oceanographic station was 40 miles offshore, and 1300 meters deep, while the second was 20 miles offshore and only 170 meters deep. See the handy infographic below to get a perspective on what those depths mean in the grand scheme of things. From an oceanographic perspective, the neatest finding of the day was our ability to detect the freshwater plume coming from the Columbia River at both those stations despite their distance from each other, and from shore! Water density is one of the key characteristics that oceanographers use to track parcels of water as they travel through the ocean conveyor belt. Certain bodies of water (like the Mediterranean Sea, or the Atlantic or Pacific Oceans) have distinct properties that allow us to recognize them easily. In this case, it was very exciting to “sea” the two-layer system we had gotten used to observing overlain with a freshwater lens of much lower salinity, higher temperature, and lower density. This combination of freshwater, saltwater, and intriguing bathymetric features can lead to interesting foraging opportunities for marine megafauna – so, what did we find out there?
Morning conditions were almost perfect for marine mammal observations – glassy calm with low swell, good, high, cloud cover to minimize glare and allow us to catch the barest hint of a blow….. it should come as no surprise then, that the first sightings of the day were seabirds and tuna!
I didn’t catch any photos of the tuna, so here’s some sunfish we spotted. photo credit: Florence Sullivan
One of the best things about being at sea is the ability to look out at the horizon and have nothing but water staring back at you. It really drives home all the old seafaring superstitions about sailing off the edge of the world. This close to shore, and in such productive waters, it is rare to find yourself truly alone, so when we spot a fishing trawler, there’s already a space to note it in the data log. Ships at sea often have “follower” birds – avians attracted by easy meals as food scraps are dumped overboard. Fishing boats usually attract a lot of birds as fish bycatch and processing leftovers are flushed from the deck. The birders groan, because identification and counts of individuals get more and more complicated as we approach other vessels. The most thrilling bird sighting of the day for me were the flocks of a couple hundred fork-tailed storm petrels.
I find it remarkable that such small birds are capable of spending 80% of their life on the open ocean, returning to land only to mate and raise a chick. Their nesting strategy is pretty fascinating too – in bad foraging years, the chick is capable of surviving for several days without food by going into a state of torpor. (This slows metabolism and reduces growth until an adult returns.)
Just because the bird observers were starting to feel slightly overwhelmed, doesn’t mean that the marine mammal observers stopped their own survey. The effort soon paid off with shouts of “Wait! What are those splashes over there?!” That’s the signal for everyone to get their binoculars up, start counting individuals, and making note of identifying features like color, shape of dorsal fin, and swimming style so that we can make an accurate species ID. The first sighting, though common in the area, was a new species for me – Pacific white sided dolphins!
A Pacific white sided dolphin leaps into view. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis
A pod of thirty or so came to ride our bow wake for a bit, which was a real treat. But wait, it got better! Shortly afterward, we spotted more activity off the starboard bow. It was confusing at first because we could clearly see a lot of splashes indicating many individuals, but no one had glimpsed any fins to help us figure out the species. As the pod got closer, Leigh shouted “Lissodelphis! They’re lissodelphis!” We couldn’t see any dorsal fins, because northern right whale dolphins haven’t got one! Then the fly bridge became absolute madness as we all attempted to count how many individuals were in the pod, as well as take pictures for photo ID. It got even more complicated when some more pacific white sided dolphins showed up to join in the bow-riding fun.
Northern right whale dolphins are hard to spot! photo credit: Florence Sullivan Taken under NMFS permit 16111 John Calambokidis
All told, our best estimates counted about 200 individuals around us in that moment. The dolphins tired of us soon, and things continued to calm down as we moved further away from the fishing vessels. We had a final encounter with an enthusiastic young humpback who was breaching and tail-slapping all over the place before ending our survey and heading towards Astoria to make our dock time.
Humpback whale breach. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis
As a Washington native who has always been interested in a maritime career, I grew up on stories of The Graveyard of the Pacific, and how difficult the crossing of the Columbia River Bar can be. Many harbors have dedicated captains to guide large ships into the port docks. Did you know the same is true of the Columbia River Bar? Conditions change so rapidly here, the shifting sands of the river mouth make it necessary for large ships to receive a local guest pilot (often via helicopter) to guide them across. The National Motor Lifeboat School trains its students at the mouth of the river because it provides some of “the harshest maritime weather conditions in the world”. Suffice it to say, not only was I thrilled to be able to detect the Columbia River plume in our CTD profile, I was also supremely excited to finally sail across the bar. While a tiny part of me had hoped for a slightly more arduous crossing (to live up to all the stories you know), I am happy to report that we had glorious, calm, sunny conditions, which allowed us all to thoroughly enjoy the view from the fly bridge.
Cape Disappointment Lighthouse at the Columbia River Bar.
Finally, we arrived in Astoria, loaded all our gear into the ship’s RHIB (Ridged Hulled Inflatable Boat), lowered it into the river, descended the rope ladder, got settled, and motored into port. We waved goodbye to the R/V Oceanus, and hope to conduct another STEM cruise aboard her again soon.
Now if the ground would stop rolling, that would be just swell.
Last but not least, here are the videos we promised you in Oceanus Day Two – the first video shows the humpback lunge feeding behavior, while the second shows tail slapping. Follow our youtube channel for more cool videos!
Today got off to a bright and early start. As soon as daylight permitted, we had spotters out on duty looking for more marine mammals. We began to survey at the north end of Heceta bank, where we again encountered many humpback whales lunge feeding. We broke transect, and got some great video footage of a pair them – so check our youtube channel next week – we’ll upload the video as soon as we get back to better internet (dial up takes some getting used to again – the whales don’t know about highspeed yet).
Humpbacks lunge feeding at surface. photo credit: Leigh Torres. Taken under NMFS permit 16111 John Calambokidis.
After working with the humpbacks to capture photo-id data for about an hour, we turned south, and ran parallel to Heceta bank until we reached the southern edge. Along the way, we counted 30 humpbacks, and many California gulls, marbled murrelets, pink footed shearwaters, and sooty shearwaters.
After lunch, we conducted a CTD cast to see how conditions might be different between the southern and northern edges of the bank. Surface temperatures increased from 12.09C to 13.2C while bottom temperatures decreased from 8.7C to 7.8C. The northern station was a textbook perfect two layer system. It had a well mixed surface layer with a steep pycnocline separating it from the colder, saltier, denser, bottom layer. The southern station still had two layers, but the pycnocline (the depth where a rapid change in density occurs, which delineates the edges of water masses) was not as steep. We are interested in these discreet measurements of ocean conditions because areas of high primary productivity (the green chlorophyll-a line) are often re-occurring hot spots of food for many levels of the food chain. Since we can’t phone the whales and ask them where to meet up, we use clues like these to anticipate the best place to start looking.
Readout of the CTD cast. The left plot has temperature in blue, and salinity in green. The right plot has density in black, chlorophyll-a in green, and oxygen in blue. observe how different variables change with depth (on the y-axes)!
We next turned west to transect the continental shelf break. Here, we were hoping to observe changes in species composition as waters got deeper, and habitat changed. The shelf break is often known as an area of upwelling and increased primary productivity, which can lead to concentrations of marine predators taking advantage of aggregations of prey. As we moved further offshore, everyone was hoping for some sperm whales, or maybe some oceanic dolphin species, and if we’re really lucky, maybe a beaked whale or two.
Black footed Albatross with immature gulls. photo credit: Leigh Torres
Today our students learned the lesson of how difficult marine mammal observation can be when our target species spend the majority of their lives underwater – where we can’t see them. While there were a couple of hours of mammal empty water in there, observers were kept busy identifying long tailed- jaegers, cassin’s auklets, murrelets, petrels, shearwaters, fulmars, and so many black-footed albatrosses, that they almost became “normal”. That being said, we did spot a fin whale, a few groups of Dall’s porpoise, and three pacific-white-sided dolphins. Unexpectedly, we also saw an unidentified shark, and several sunfish (mola mola)!
Humpback whale profile – notice the hump before the dorsal fin. photo credit: Amanda Holdman. Taken under NMFS permit 16111 John Calambokidis.Fin Whale profile – notice how long the back is before the fin, and how pointed the dorsal fin is compared to the humpback. photo credit: Amanda Holdman. Taken under NMFS permit 16111 John Calambokidis.
Last but not least, we engaged in a long standing oceanographic tradition, which is to draw on Styrofoam cups, and send them down to Davy Jone’s Locker attached to the CTD. When you bring them back up, the pressure has caused them to shrink to a fraction of their original size, which is an excellent demonstration of the crushing power of pressure (and why its harder to build a submarine than a rocket).
Shrunken cups! The first row have been sent down to 1400m, while the back row are still full size!
Now, we are steaming north toward Astoria Canyon, where we hope to make some more sightings in the morning. Stand by for news from our final day at sea.
Fin Whale. photo credit Amanda Holdman. Taken under NMFS permit 16111 John Calambokidis.Dahl’s Porpoise. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis.
The GEMM lab is adventuring out into the wild blue yonder of open ocean sampling and educational outreach! Leigh is the chief scientist onboard the R/V Oceanus for the next two days as we sail through Oregon waters in search of marine megafauna. Also onboard are four local teachers and five high school students who are learning the tricks of the trade. Amanda and I are here to help teach basic oceanography and distance sampling techniques to our enthusiastic students.
Science Party musters in the dry lab for safety debrief. photo credit: Florence Sullivan
We started the morning with safety briefings, and headed out through the Newport breakwater, direction: Stonewall Bank. Stonewall is a local bathymetric feature where upwelling often occurs, leading to a productive ecosystem for both predators and prey. Even though our main sampling effort will be offshore this trip, we didn’t even make out of the harbor before recording our first gray whale and California sea lion sightings.
California Sea Lions on the Newport buoy. Taken under NMFS permit 16111 John Calambokidis
Our students (and their teachers) are eager and quick to catch on as we teach them new methodologies. Amanda and I had prepared presentations about basic oceanographic and distance sampling methods, but really the best way to learn is to jump in and go. We’ve set up a rotation schedule, and everyone is taking turns scanning the ocean for critters, deploying and recovering the CTD, logging data, and catching plankton.
A small pod of Orca. Photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis
So far, we have spotted gray whales, sea lions, a pod of (lightning speed) killer whales, lots of seagulls, northern fulmars, sooty shearwaters, storm petrels, and cormorants, but today’s highlight has to the last sighting of ~42 humpback whales. We found them at the Northern edge of Heceta Bank – a large rocky reef which provides structural habitat for a wide variety of marine species. As we approached the area, we spotted one whale, and then another. At first, our spotters had no trouble inputting the data, getting photo-ID shots, and distinguishing one whale from the next, but as we continued, we were soon overwhelmed. With whale blows surrounding us on all sides, it was hard to know where to look first – here a surface lunge, there, a breach, a spout, a fluke, a flipper slap! The surface activity was so dense and enthralling, it took a few moments before realizing there were some sea lions in the feeding frenzy too!
Five humpback whales surface at once. photo credit: Leigh Torres. Taken under NMFS permit 16111 John Calambokidis
We observed the group, and tried to document as many individuals as possible as the sunset faded into night. When poor visibility put a stop to the visuals, we hurried to do a plankton tow and CTD cast to find some environmental insights for such a gathering. The CTD revealed a stratified water column, with two distinct layers, and the plankton tow brought up lots of diatoms and krill. As one of the goals of this cruise is to explore how marine mammals vary with ocean gradients, this is a pretty cool way to start.
A humpback whale lunge feeds. Photo credit: Leigh Torres. Taken under NMFS permit 16111 John Calambokidis
A long day observing has left us all exhausted, but not too tired to share our excitement. Stay tuned for more updates from the briny blue!
Follow this link for real time view of our beautiful ship! : http://webcam.oregonstate.edu/oceanus
Humpback flukes for photo ID. photo credit: Leigh Torres. Taken under NMFS permit 16111 John Calambokidis
By: Cathryn Wood, Lawrence University ’17, summer REU in the GEMM Lab
Greetings from Port Orford! My name is Cathryn, and I am the fourth member of the GEMM Lab’s gray whale foraging ecology research team, which includes Florence, Kelli, and the other Catherine (don’t worry, I go by Cat). Nearly 5 weeks into field season, I am still completely amazed with my first West Coast experience and doing what I’ve always dreamt of: studying marine mammals. Coming from Michigan’s Upper Peninsula, this may seem slightly out of place, but my mom can attest; she read “Baby Beluga” to me every night when I was a toddler. Now a rising senior majoring in biology at Lawrence University, I’ve been focusing my coursework on aquatic and marine ecology to prepare for graduate school where I plan to specialize in marine science. Being part of this research is a very significant step for me into the field.
So how did I end up here, as part of this amazing project and dream, women-in-science team? I am interning through OSU’s Ocean Sciences REU program at the Hatfield Marine Science Center, where the GEMM Lab is located. REU stands for “Research Experience for Undergraduates”, and is an NSF-funded research internship program found in numerous universities around the country. These internships allow undergrads to conduct independent research projects under the guidance of a faculty mentor at the program’s institution. I applied to several REUs this past winter, and was one of 12 undergrads accepted for the program at HMSC. Each of us is paired with different faculty members to work on various projects that cover a diverse range of topics in the marine sciences; everything from estuarine ecology, to bioacoustics. I was ecstatic to learn that I had been paired with Dr. Torres as my faculty mentor to work on Florence’s gray whale project, which had been my first choice during the application process.
My particular research this summer is going to complement Florence’s master’s thesis work by asking new questions regarding the foraging data. While her project focuses on the behavioral states of foraging whales, I will be looking at the whale tracks to see if there are patterns in their foraging behavior found at the individual level. Traditionally, ecological studies have accepted classical niche theory, treating all individuals within a population as ecological equivalents with the same niche width. Any variances present among individuals are often disregarded as having an insignificant consequence on the population dynamics as a whole, but this simplification can overlook the true complexity of that population . The presence of niche variation among conspecifics is known to occur in at least 93 species across a diverse array of taxa, so the concept of individual specialization, and how it can affect ecological processes is gaining recognition progressively in the field (Bolnick et al., 2003). My goal is to determine whether or not the gray whales in this study, and presumably others in the Pacific Coast Feeding Group (PCFG), exhibit individual specialization in their foraging strategies . There are many ways in which individuals can specialize in foraging, but I will be specifically determining if fine scale spatial patterns in the location of foraging bouts exists, regardless of time.
To address my question, I am using the whale tracking data from both 2015 and 2016, and learning to use some very important software in the spatial ecology world along the way through a method that Dr. Torres introduced to me. Starting in ArcGIS, I generate a kernel density layer of a raw track (Fig. 1 ), which describes the relative distribution of where the tracked whale spent time (Fig. 2 ). Next, using the isopleth function in the software Geospatial Modelling Environment, I generate a 50% density contour line that distinguishes where the whale spent at least 50% of its time during the track (Fig. 3 ). Under the assumption that foraging took place in these high density areas, we use these 50% contour lines to describe foraging bout locations. I now go back to ArcGIS to make centroids within each 50% line, which mark the exact foraging bout locations (Fig. 4 ).
Fig. 1 Raw individual whale track.Fig. 2 Kernel Density map of whale track.Fig. 3 50% isopleth contours of locations with highest foraging densitiesFig. 4 Final centroids to signify foraging bouts
These centroids will be determined for every track by an individual whale, and then compared relative to foraging locations of all tracked whales to determine if the individual is foraging in different locations than the population. Then, the tracks of individuals who repeatedly visit the site at least three times will be compared with one another to determine if the repeat whales show spatial and/or temporal patterns in their foraging bout locations, and if specialization at a fine scale is occurring in this population. If you did not quite follow all those methods, no worries, it was a lot for me to take in at first too. I’ve finally gotten the hang of it though, and am grateful to now have these skills going into grad school.
Because I am interested in behavioral ecology and the concept of individuality in animal populations, I am extremely excited to see how this research plays out. Results could be very eye-opening into the fine scale foraging specialization of the PCFG sub-population because they already demonstrate diet specialization on mysid (as opposed to their counterparts in the Bering Sea who feed on benthic organisms) and large scale individual residency patterns along the Pacific Northwest (Newell, 2009; Calambokidis et al., 2012). Most significantly, understanding how individuals vary in their feeding strategies could have very important implications for future conservation measures for the whales, especially during this crucial foraging season where they replenish their energy reserves. Management efforts geared for an “average population” of gray whales could ultimately be ineffective if in fact individuals vary from one another in their foraging strategies. Taking into account the ways in which variation occurs amongst individuals is therefore crucial knowledge for successful conservation approaches.
My project is unique from those of the other REUs because I am simultaneously in the midst of assisting in field season number two of Florence’s project. While most of the other interns are back at Hatfield spending their days in the lab and doing data analyses like a 9-5 job, I am with the team down in Port Orford for field season. This means we’re out doing research every dawn as weather allows. Though I may never have an early bird bone in my body, the sleepy mornings are totally worth it because ecology field work is my favorite part of research. To read more about our methods in the field, check out Florence’s post.
Since Catherine’s last update, we’ve had an eventful week. To our dismay, Downrigger Debacle 2.0 occurred. (To read about the first one, see Kelli’s post). This time it was not the line – our new line has been great. It was a little wire that connected the downrigger line to the pipe that the GoPro and TDR are connected to. It somehow snapped due to what I presume was stress from the currents. Again, it was Catherine and I in the kayak, with a very successful morning on the water coming to a close when it happened. Again, I was in the bow, and she was in the stern deploying the equipment – very déjà vu. When she reeled in an equipment-less line, we at first didn’t know how to break it to Florence and Kelli who were up on the cliff that day. Eventually, Catherine radioed “Brace yourselves…” and we told them the bad news. Once again, they both were very level-headed, methodical, and un-blaming in the moments to follow. We put together the same rescue dive team as last time, and less than a week later, they set off on the mission using the GPS coordinates I had marked while in the kayak. Apparently, between the dredging taking place in the harbor and the phytoplankton bloom, visibility was only about 2 feet during the dive, but they still recovered the equipment, with nothing but baked goods and profuse thanks as payment. We are very grateful for another successful recovery, and are confident that our new attachment mechanism for the downrigger will not require a third rescue mission (Fig. 6-8). Losing the equipment twice now has taught us some very important things about field work. For one, no matter how sound you assume your equipment to be, it is necessary to inspect it for weak points frequently – especially when salt water and currents are in the picture. Perhaps even more importantly, we’ve gotten to practice our problem solving skills and see firsthand how necessary it is to act efficiently and calmly when something goes wrong. In ecological field research you have to be prepared for anything.
Fig. 5 Original setup of GoPro and TDR.Fig. 6 Photo taken after the wire that connected the pole to the downrigger line snapped.Fig. 7 New mechanism for attaching the pole to the downrigger line.Fig. 8 Equipment rescue team: Aaron Galloway and Taylor Eaton diving, Greg Ryder operating the boat, and Florence on board to direct the GPS location of where the equipment was lost.
In other news, unlike our slow-whale days during the first two weeks of the project, we have recently had whales to track nearly every day from the cliff! In fact, the same, small, most likely juvenile, whale pictured in Catherine’s last post has returned several times, and we’ve nicknamed her “Buttons” due to two distinguishing white spots on her tail peduncle near the fluke. Though we tend to refer to Buttons as “her”, we cannot actually tell what the sex is definitively…until now. Remember in Catherine’s post when she described how Buttons defecated a lot, and how our team if, given the opportunity, is supposed to collect the feces when we’re out in the kayak for Leila’s project? Everything from hormone levels to reproductive status to, yes, sex, is held in that poop! Well, Miss (or Mr.) Buttons was in Tichenor Cove today, and to our delight, she performed well in the defecation department once again. Florence and I were on cliff duty tracking her and Kelli and Catherine were in Tichenor on the kayak when we first noticed the defecation. I then radioed down to the kayak team to stop what they were doing and paddle quickly to go collect it before it sank (Fig. 9). Even in these situations, it is important to stay beyond 100 yards of the animal, as required by the MMPA. Florence and I cheered them on and our ladies did indeed get the poop sample, without disturbing the whale (Fig. 10). It was a sight to behold.
Fig. 9 Kelli and Catherine on a mission.Fig. 10 Kelli and Catherine collecting the feces.
We were able to track Buttons for the remainder of our time on the cliff, and were extremely content with the day’s work as we packed all the gear up later in the afternoon. Right before we were about to leave, however, Buttons had one more big treat for us. As we looked to the harbor before starting the trek back to the truck, we paused briefly after noticing a large, white splash in the middle of the harbor, not far from the dock. We paused for a second and thought “No, it can’t be, was that —?” and then we see it again and unanimously yelled “BREACH!” Buttons breached about five times on her way back to Tichenor Cove from where she had been foraging in Mill Rocks. It is rare to see a gray whale breach, so this was really special. Florence managed to capture one of the breaches on video:
At first I thought a big ole humpback had arrived, but nope, it was our Buttons! I am in awe of this little whale, and am forever-grateful to be in the presence of these kinds of moments. She’s definitely made her splash here in Port Orford. I think our team has started to as well.
Bolnick, D. I., Svanback, R., Fordyce, J. A., Yang, L. H., Davis, J. M., Hulsey, C. D., & Forrister, M. L. (2003). Ecology of Individuals: Incidence and Implications of Individual Specialization. The American Naturalist, 161(1), 28.
Calambokidis, J., Laake, J. L., & Klimek, A. (2012). Updated analysis of abundance and population structure of seasonal gray whales in the Pacific Northwest, 1998-2010 (Vol. 2010).
Newell, C. (2009). Ecological Interrelationships Between Summer Resident Gray Whales (Eschrichtius robustus) and Their Prey, Mysid Shrimp (Holmesimysis sculpta and Neomysis rayi) along the Central Oregon Coast.
By: Catherine Lo, Research Intern, Oregon State University ‘16
Hello everyone! My name is Catherine Lo and I am a recent graduate from Oregon State University with a Bachelor’s of Science in Biology with a focus in Marine Biology. It has been an incredible whirlwind leading up to this point: long nights studying for finals, completing my degree, and planning the next steps for my future. I am fortunate to be working as a summer research intern for the GEMM Lab under the supervision of Dr. Leigh Torres and Msc. student Florence Sullivan in their research on the foraging ecology of gray whales. I have dreamed of working with marine mammals, potentially as a research veterinarian and so, capturing this position has been a great opportunity to begin my career.
The days go slow, but the weeks go fast. It’s already week 4 of our field season and the team and I are definitely in the groove of our research. The alarm(s) goes off at 5:00 AM…okay maybe closer to 5:30 AM (oops!), getting dressed for either the kayak or cliff based work, scarfing down breakfast that is usually a diet consisting of toast and peanut butter, and then heading off to the beach to launch the kayak. But this week it was different. A dredging event in Port Orford coordinated by the US Army Corps of Engineers is now taking place right next to the port’s jetty near our study site (Figure 1). This is an important process to move the sediment built up during the year in order for ships to safely navigate in and out of the port. We knew this was going to happen at some point over the summer, and worried that it might impact our research methods and objectives, but at the same time it offers some new opportunities: the chance to see how our GoPro and mysid sampling methods in Tichenor Cove are impacted by the sediment flow from the dredging activities.
Figure 1. View of the dredger from the cliff field site in Port Orford.
My teammate Kelli and I were stationed on the cliff during the first deposit of sediment after the dredge’s first night and morning’s worth of scooping sand. None of us knew where the actual deposit site would be so we kept a good eye on it. The ship headed past the jetty. Turned around and, as a concerned feeling mustered within our field team, it began lowering the platform holding the sand just 250 yards away from our primary study site in Tichenor Cove! At this point, we knew things were going to be different in our samples. Unfortunately along with the sediment stirring up from dredging, we think a phytoplankton bloom is occurring simultaneously. Our GoPro footage lately has been rather clouded making it difficult to identify any mysid relative to our past footage. You can compare Figure 2 to the GoPro image found in Figure 2 of a previous post. It is times like these that we learn how dynamic the ocean is, how human activity can alter the ocean ecosystem, and how to adapt to changes, whether these adaptations are within our reach or not. We are interested to see how our sample sites will change again over time as the dredging operation finishes and the phytoplankton bloom ends.
Figure 2. This GoPro image taken in Tichenor Cove illustrates exactly how murky our view of the water column is with the sediment dredging operation in close proximity.
Aside from the current water clarity situation, we’ve also had some exciting moments! Given how few whales we’ve seen thus far and how the ones we have tracked are predominately hanging by Mill Rocks, which is ~1km east of Tichenor Cove, Dr. Leigh Torres—our head advisor—thought it would be a good idea to check out the mysid scene over there to see what the attraction was. So, we sent our kayak team over there to conduct a few GoPro drops and zooplankton net tows and figure out what is so enticing for the whales.
While conducting this sampling work at Mill Rocks, I and my teammate were lucky enough to encounter a gray whale foraging. And believe me, we were going “off-the-walls” as soon as we heard from the cliff team and saw a blow as the whale surfaced nearby. It was one of those “best time of my life” moments where my dreams of kayaking this close to a whale came true. We fumbled around for our waterproof camera to get clear shots of its lateral flanks for photo identification while also trying to contain our excitement to a more decent level, and at the same time we had to make sure we were not in the whale’s path. There it was; surface after surface, we admired the immense size and beauty of a wild animal before our eyes. The worst part of it was when our camera battery died not long after taking a few pictures, but in a way it gave us a chance to really appreciate the existence of these animals. Note to self during research: always check your batteries are fully charged before heading out!
It baffles me how so often people walk along beaches or drive by without knowing an animal as incredible as this whale is just outside of the shoreline. Every time I’m inside pulling out time stamps or doing photo identification, I always think, “I wonder if there’s a whale in Tichenor Cove or at Mill Rocks right now…Yeah, there probably is one”. Alas, the data management work needs to be done and there’s always the next day for an opportunity of a sighting.
For a few days, our kayak team wasn’t able to work due to a small craft advisory. If you’ve ever been to Port Orford, you’d understand the severity of how windy it gets here. Ranging between 15 knots to 25 knots as early as 7am, so it gets rather difficult to maintain position at each of our sampling stations in our kayak. Fortunately our cliff team was able to set out. We were lucky to see a small whale foraging inside Tichenor Cove and later move onto Mill Rocks. This little one was giving us quite a show! Almost every time it came to the surface, defecation was observed shortly after. As unpleasant as feces might be, it can actually provide an abundance of information about a specific whale including sex, reproductive status, hormone levels, and much more. While doing our research, we are always keeping an eye out for signs of defecation in order to collect samples for another lab member’s PhD work. Here you can check out more information about Leila’s research. Figure 3 depicts a great image of defecation captured by our cliff team.
Figure 3. Gray whale defecating as it dives into the water in Tichenor Cove.Figure 4. Gray whale swimming in Tichenor Cove taken by fellow intern Cathryn Wood.
In addition to helping out Leila’s work, we recently began a collaboration with Aaron Galloway from The Oregon Institute of Marine Biology (OIMB). Aaron and his post-doc are looking at the fatty acid composition of mysid as an approach to eventually infer the diet of an aquatic animal. Check out his website which is linked to his name to learn more about the basis of his approach! While we collect mysid samples for them, in return they give us substantial information about the energy content of the mysid. This information on the energetic content of mysid will help the GEMM Lab answer questions about how much mysid gray whales need to eat.
Oregon State University and University of Oregon have a long-standing, intense rivalry. However, as an Alumna from Oregon State, I am amazed and thrilled to see how these two institutions can come together and collaborate. I mean, we’re all here for the same thing. Science, right? It creates the opportunity to apply integrative research by taking advantage of various expertise and resources. If we have those chances to reach out to others, why not make the most of it? In the end, sound science is what really matters, not rooting for the ducks or beavers.
My marine science background is based on my experiences looking at tidepools and hopping around on rocks to understand how vast intertidal communities range from invertebrates to algae. These experiences were an incredible part of my life, but now I look at the ocean unsure of what animals or environmental situations I might encounter. That’s what makes it so attractive. Don’t get me wrong. The intertidal will always hold a special place in my heart, but the endless possibilities of being a part of this marine mammal research team is priceless. I have learned so much about myself including my strengths and weaknesses. Living in Port Orford, which is a small coastal town with just a little over 1,000 people gives you a new perspective. The community has been very welcoming and I have appreciated how so much interest is placed on the kind of work we do. As I eat my nightly bowl of ice cream, I think about how, from here on out, the good and the bad can only bring a lifetime of skills and memories.
Figure 5. Me being extremely happy to be out on the kayak on a beautiful morning.
By: Kelli Iddings, MSc Student, Duke University, Nicholas School of the Environment
The excitement is palpable as I wait in anticipation. But finally, “Blow!” I shout as I notice the lingering spray of seawater expelled from a gray whale as it surfaces to breathe. The team and I scurry about the field site taking our places and getting ready to track the whale’s movements. “Gray whale- Traveling- Group 1- Mark!” I exclaim mustering enough self-control to ignore the urge to drop everything and stand in complete awe of what in my mind is nothing short of a miracle. I’ve spotted a gray whale searching and foraging for food! As a student of the Master of Environmental Management program at Duke University, I am collaborating on a project in Port Orford, Oregon where my team and I are working to gain a better understanding of the interactions between the Pacific Coast Feeding Group (PCFG) gray whales and their prey. Check out this blog post written earlier by my teammate Florence to learn more about the methods of the project and what motivated us to take a closer look at the foraging behavior of this species.
Understanding the dynamics of gray whale foraging within ecosystems where they are feeding is essential to paint a more comprehensive picture of gray whale health and ecology—often with the intent to protect and conserve them. A lot of our recent effort has been focused on developing and testing methods that will allow us to answer the questions that we are asking. For example, what species of prey are the PCFG whales feeding on in Port Orford? Based on the results of a previous study (Newell and Cowles 2006) that was conducted in Depoe Bay, Oregon, and a lot of great knowledge from the local fisheries and the Port Orford community, we hypothesized that the whales were feeding on a small, shrimp-like crustacean in the order Mysida. Given the results of our videos, and the abundance of mysid, it looks like we are right (Fig. 1)!
Figure 1: Mysids, only 5-25mm in length, collected in Tichenor Cove using a downrigger to lower a weighted plankton net into the water column from our kayak.Mysids are not typically the primary food source of gray whales. In their feeding grounds in the Bering and Chukchi Seas near Alaska, the whales feed on benthic amphipods on the ocean floor by sucking up sediment and water and pushing it through baleen plates that trap the food as the water and sediment is filtered out. However, gray whales demonstrate flexible feeding strategies and are considered opportunistic feeders, meaning they are not obligate feeders on one prey item like krill-dependent blue whales. In Oregon, mysid congregate in dense swarms by the billions, which we hypothesize, makes it energetically worthwhile for the massive 13-15m gray whales to hang around and feed! Figure 2 illustrates a mysid swarm of this kind in Tichenor Cove.
Figure 2: Image captured using a Hero 4 Black GoPro. Rocky Substrate is visible in lower portion of image and a clear swarm of mysid is aggregated around this area.
Once we know what the gray whales are eating, and why, we ask follow up questions like how is the distribution of mysid changing across space and time, if at all? Are there patterns? If so, are the patterns influencing the feeding behavior and movement of the whales? For the most part, we are having success characterizing the relative abundances of mysid. No conclusions can be made yet, but there are a few trends that we are noticing. For instance, it seems that the mysid are, as we hypothesized, very dense and abundant around the rocky shoreline where there are kelp beds. Could these characteristics be predictors of critical habitat that whales seek as foraging grounds? Is it the presence of kelp that mysid prefer? Or maybe it’s the rocky substrate itself? Distance to shore? Time and data analysis will tell. We have also noticed that mysid seem to prefer to hang out closer to the bottom of the water column. Last, but certainly not least, we are already noticing differences in the sizes and life stages of the mysid over the short span of one week at our research site! We are excited to explore these patterns further.
The biggest thing we’re learning out here, however, is the absolute necessity for patience, ingenuity, adaptability, and perseverance in science. You heard that right, as with most things, I am learning more from our failures, than I am from our successes. For starters, understanding mysid abundance and distribution is great in and of itself, but we cannot draw any conclusions about how those factors are affecting whales if the whales don’t come! We were very fortunate to see whales while training on our instruments in Newport, north of our current study site. We saw whales foraging, whales searching, mother/calf pairs, and even whales breaching! Since we’ve been in Port Orford, we have seen only three whales, thrown in among the long hours of womanpower (#WomenInScience) we have been putting in! We are now learning the realities of ecological science that >gasp< fieldwork can be boring! Nevertheless, we trust that the whales will hear our calls (Yes, our literal whale calls. Like I said, it can get boring up on the cliff) and head on over to give the cliff team in Port Orford some great data—and excitement!
Then, there is the technology. Oh, the joys of technology. You see I’ve never considered myself a “techie.” Honestly, I didn’t even know what a hard drive was until some embarrassing time in the not-so-distant past. And now, here I am working on a project that is using novel, technology rich approaches to study what I am most passionate about. Oh, the irony. Alas, I have been putting on my big girl britches, saddling up, and taking the whale by the fluke. Days are spent syncing a GoPro, Time-Depth Recorder (TDR), GPS, associated software, and our trusty rugged laptop, all the while navigating across multiple hard drives, transferring and organizing massive amounts of data, reviewing and editing video footage, and trouble shooting all of it when something, inevitably, crashes, gets lost, or some other form of small tragedy associated with data management. Sounds fun, right? Nonetheless, within the chaos and despair, I realize that technology is my friend, not my foe. Technology allows us to collect more data than ever before, giving us the ability to see trends that we could not have seen otherwise, and expending much less physical effort doing so. Additionally, technology offers many alternatives to other invasive and potentially destructive methods of data collection. The truth is if you’re not technologically savvy in science these days, you can expect to fall behind. I am grateful to have an incredible team of support and such an exciting project to soften the blow. Below (Fig. 3) is a picture of myself embracing my new friend technology.
Figure 3: Retrieving the GoPro, and some tag-a-long kelp, from the water after a successful deployment in Tichenor Cove.
Last but not least, there are those moments that can best be explained by the Norwegian sentiment “Uff da!” I was introduced to the expression while dining at The Crazy Norwegian, known famously for having the best fish and chips along the entire west coast and located dangerously close to the field station. The expression dates back to the 19th century, and is used readily to concisely convey feelings of surprise, astonishment, exhaustion, and sometimes dismay. This past week, the team was witness to all of these feelings at once as our GoPro, TDR, and data fell swiftly to the bottom of the 42-degree waters of Tichenor cove after the line snapped during deployment. Uff da!!! With our dive contact out of town, red tape limiting our options, the holiday weekend looming ahead, and the dreadful thought of losing our equipment on a very tight budget, the team banded together to draft a plan. And what a beautiful plan it was! The communities of Port Orford, Oregon State University, and the University of Oregon’s Institute of Marine Biology came together in a successful attempt to retrieve the equipment. We offer much gratitude to Greg Ryder, our retrieval boat operator, OSU dive safety operator Kevin Buch, and our divers, Aaron Galloway and Taylor Eaton! After lying on the bottom of the cove for almost three days, the divers retrieved our equipment within 20 minutes of the dive – thanks to the quick and mindful action of our kayak team to mark a waypoint on the GPS at the time of the equipment loss. Please enjoy this shot (Fig. 4) of Aaron and Taylor surfacing with the gear as much as we do!
Figure 4: Aaron Galloway and Taylor Eaton surface with our lost piece of equipment after a successful dive retrieval mission.
The moral of the story is that science isn’t easy, but it’s worth it. It takes hard work, long hours, frustration, commitment, collaboration, and preparedness. But moments come along when your team sits around a dining room table, exhausted from waking and paddling at 5 am that morning, and continues to drive forward. You creatively brainstorm, running on the fumes of the passion and love for the ocean and creatures within it that brought everyone together in the first place; each person growing in his or her own right. Questions are answered, conclusions are drawn, and you go to bed at the end of it all with a smile on your face, anxiously anticipating the little miracles that the next day’s light will bring.
References
Newell, C. and T.J. Cowles. (2006). Unusual gray whale Eschrichtius robustus feeding in the summer of 2005 off the central Oregon Coast. Geophysical Research Letters, 33:10.1029/2006GL027189
Hello Everyone, and welcome back for season two of our ever-expanding research project(s) about the gray whales of the Oregon coast!
Overall, our goal is document and describe the foraging behavior and ecology of the Pacific Coast Feeding Group of Gray Whales on the Oregon Coast. For a quick recap on the details of this project read these previous posts:
During this summer season, the newest iteration of team ro”buff”stus will be heading back down to Port Orford, Oregon to try to better understand the relationship between gray whales and their mysid prey. Half the team will once again use the theodolite from the top of Graveyard Point to track gray whales foraging in Tichenor Cove, the Port of Port Orford, and the kelp beds near Mill Rocks. Meanwhile, the other half of the team will use the R/V Robustus (i.e. a tandem ocean kayak named after our study species – Eschrichtius robustus, the gray whale) to repeatedly deploy a GoPro camera at several sampling locations in Tichenor cove. We hope that by filming vertical profiles of the water column, we will be able to create an index of abundance for the mysid to describe their temporal and spatial distribution of their swarms. We’re particularly interested in the differences between mysid swarm density before and after a whale forages in an area, and how whale behaviors might change based on the relative density of the available prey.
Ready to take the R/V Robustus out for her maiden voyage in Port Orford to test some of our new equipment. photo credit: Leigh Torres
In theory, asking these questions seems simple – get in the boat, drop the camera, compare images to the whale tracklines, get an answer! In reality, this is not the case. A lot of preparatory work has been going on behind the scenes over the last six months. First, we had to decide what kind of camera to use, and decide what sort of weighted frame to build to get it to sink straight to the bottom. Then came the questions of deployment by hand versus using a downrigger,
Example A why it is a bad idea to try to sample during a diatom bloom – You can’t see anything but green.
what settings to use on the camera, how fast to send it down and bring it back up, what lens filters are needed (magenta) and other logistical concerns. (Huge thank you to our friends at ODFWMarine Reserves Program for the help and advice they provided on many of these subjects.) We spent some time in late May testing our deployment system, and quickly discovered that sampling during a diatom bloom is completely pointless because visibility is close to nil.
However, this week, we were able to test the camera in non-bloom conditions, and it works! We were able to capture images of a few small mysid swarms very near the bottom of the water column, and we didn’t need external lights to do it. We were worried that adding extra lights would artificially attract mysid to the camera, and bias our measurements, as well as potentially disturbing the whale’s foraging behavior. (Its also a relief because diving lights are expensive, and would have been one more logistical thing that could go wrong. General advice: Always follow the KISS method when designing a project – keep it simple, ——!)
This image is taken at a depth of ~10 meters, with no color corrective filter on the lens – notice how blurry the mysid are.This is empty water, in the mid water columnMuch clearer Mysid! This time with a magenta filter on the lens to correct the colors for us.
My advisor recently introduced me to the concept of the “7 Ps”; Proper Prior Planning Prevents Piss Poor Performance. To our knowledge, we are the first group to try to use GoPro cameras to study the spatial and temporal patterns of zooplankton aggregations. With new technology comes new opportunities, but we have to be systematic and creative in how we use them. Trial and error is an integral part of developing new methods – to find the best technique, and so that our work can be replicated by others. Now that we know the GoPro/Kayak set-up is capable of capturing useable imagery, we need to develop a protocol for how to process and quantify the images, but that’s a work in progress and can wait for another blog post. Proper planning also includes checking last year’s equipment to make sure everything is running smoothly, installing needed computer programs on the new field laptop, editing sampling protocols to reflect things that worked well last year, and expanding the troubleshooting appendixes so that we have a quick reference guide for when things go wrong in the field. I am sure that we will run into more weird problems like last year’s “Chinese land whale”, but I also know that we would have many more difficulties if we had not been planning this field effort for the last several months.
Planning our sampling pattern in Tichenor Cove.
Team Ro”buff”stus is from all over the place this year – we will have members from Oregon, North Carolina and Michigan – and we are all meeting for the first time this week. The next two weeks are going to be a whirlwind of introductions, team bonding, and learning how to communicate effectively while using the theodolite, our various computer programs, GoPro, Kayak, and more! We will keep the blog updated with our progress, and each team member will post at least once over the course of the summer. Wish us luck as we watch for whales, and feel free to join in the fun on pretty much any cliff-side in Oregon (as long as you’ve got a kelp bed nearby, chances are you’ll see them!)
Over the past few months I have been slowly (and I do mean SLOWLY – I don’t believe I’ve struggled this much with learning a new skill in a long, long time) learning how to work in “R”. For those unfamiliar with why a simple letter might cause me so much trouble, R is a programming language and free software environment suitable for statistical computing and graphing.
My goal lately has been to interpolate my whale tracklines (i.e. smooth out the gaps where we missed a whale’s surfacing by inserting artificial locations). In order to do this I needed to know (1) How long does a gap between fixes need to be to identify a missed surfacing? (2) How many artificial points should be used to fill a given gap?
The best way to answer these queries was to look at a distribution of all of the time steps between fixes. I started by importing my dataset – the latitude and longitude, date, time, and unique whale identifier for each point (over 5000 of them) we recorded last summer. I converted the locations into x & y coordinates, adjusted the date and time stamp into the proper format, and used the package adehabitatLT to calculate the difference in times between each fix. A package known as ggplot2 was useful for creating exploratory histograms – but my data was incredibly skewed (Fig 1)! It appeared that the majority of our fixes happened less than a minute apart from each other. When you recall that gray whales typically take 3-4 short breathes at the surface between dives, this starts to make a lot of sense, but we had anticipated a bimodal distribution with two peaks: one for the quick surfacings, and one for the surfacings between 4-5 minutes dives. Where was this second peak?
Fig. 1. Histogram of the difference in time (in seconds on x-axis) between whale fixes.
Sometimes, calculating the logarithm of one of your axes can help tease out more patterns in your data – particularly in a heavily skewed distribution like Fig. 1. When I logged the time interval data, our expected bimodal distribution pattern became evident (Fig. 2). And, when I back-calculate from the center of the two peaks we see that the first peak occurs at less than 20 seconds (e^2.5 = 18 secs) representing the short, shallow blow intervals, or interventilation dives, and that the second peak of dives spans ~2.5 minutes to ~5 minutes (e^4.9 = 134 secs, e^5.7 = 298 secs). Reassuringly, these dive intervals are in agreement with the findings of Stelle et al. (2008) who described the mean interval between blows as 15.4 ± 4.73 seconds, and overall dives ranging from 8 seconds to 11 minutes.
Fig. 2. Histogram of the log of time difference between whale fixes.
So, now that we know what the typical dive patterns in this dataset are, the trick was to write a code that would look through each trackline, and identify gaps of greater than 5 minutes. Then, the code calculates how many artificial points to create to fill the gap, and where to put them.
Fig. 3. A check in my code to make sure the artificial points are being plotted correctly. The blue points are the originals, and the red ones are new.
One of the most frustrating parts of this adventure for me has been understanding the syntax of the R language. I know what calculations or comparisons I want to make with my dataset, but translating my thoughts into syntax for the computer to understand has not been easy. With error messages such as:
Error in match.names(clabs, names(xi)) :
names do not match previous names
Solution: I had to go line by line and verify that every single variable name matched, but turned out it was a capital letter in the wrong place throwing the error!
Error in as.POSIXct.default(time1) :
do not know how to convert ‘time1’ to class “POSIXct”
Solution: a weird case where the data was in the correct time format, but not being recognized, so I had to re-import the dataset as a different file format.
Error in data.frame(Whale.ID = Whale.ID, Site = Site, Latitude = Latitude, : arguments imply differing number of rows: 0, 2, 1
Solution: HELP! Yet to be solved….
Is it any wonder that when a friend asks how I am doing, my answer is “R is kicking my butt!”?
Science is a collaborative effort, where we build on the work of researchers who came before us. Rachael, a wonderful post-doc in the GEMM Lab, had already tackled this time-based interpolation problem earlier in the year working with albatross tracks. She graciously allowed me to build on her previous R code and tweak it for my own purposes. Two weeks ago, I was proud because I thought I had the code working – all that I needed to do was adjust the time interval we were looking for, and I could be off to the rest of my analysis! However, this weekend, the code has decided it doesn’t work with any interval except 6 minutes, and I am lost.
But sometimes, when you’ve been staring at the problem for hours, what you really need is a little praise for trying your best. So, if you are an R user, go download this package: praise, load the library, and type praise() into your console. You won’t regret it (See Fig. 4).
Fig. 4. A little compliment goes a long way to solving a headache.
Thank you to Rachael who created the code in the first place, thanks to Solene who helped me trouble shoot, thanks to Amanda for moral support. Go GEMM Lab!
Why do pirates have a hard time learning the alphabet? It’s not because they love aaaR so much, it’s because they get stuck at “c”!
Stelle, L. L., W. M. Megill, and M. R. Kinzel. 2008. Activity budget and diving behavior of gray whales (Eschrichtius robustus) in feeding grounds off coastal British Columbia. Marine mammal science 24:462-478.
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