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.

 

Sea Otter Management in the U.S.

By Dominique Kone, Masters Student in Marine Resource Management

Since the first official legal protections in 1911, the U.S. has made great strides in recovering sea otter populations. While much of this progress is due to increased emphasis on understanding sea otter behavior, biology, and ecology, there are also several policies that have been just as instrumental in making sea otter conservation efforts successful. Here, I provide a brief overview of the current legal and regulatory policies used to manage sea otters in the U.S. and explain why having a base understanding of these tools can help our lab as we look into the potential reintroduction of sea otters to the Oregon coast.

Sea otter with pup, Prince William Sound, Alaska. Source: Patrick J. Endres

When we talk about sea otter management in the U.S., the two most obvious laws that come to mind are the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA). In short, the MMPA seeks to prevent the take – including kill, harass, capture, or disturb – or importation of marine mammals and marine mammal products[1]. While the ESA seeks to protect and recover imperiled species – not just marine mammals – and the ecosystems which they depend upon[2]. Both laws are similar in the sense that their primary objectives are to protect and recover at-risk species. However, marine mammals will always be protected under the MMPA, but will only be protected under the ESA if the species is considered threatened or endangered.

On the federal level, the U.S. Fish and Wildlife Service (the Service) is primarily responsible for managing sea otter populations. In the U.S., we manage sea otter populations as five distinct stocks, which differ in their population size and geographic distribution – located in California, Washington, and Alaska state waters (Fig. 1). Because sea otters are divided into these single stocks, management decisions – such as recovery targets or reintroductions – are made on a stock-by-stock basis and are dependent on the stock’s population status. Currently, two of these stocks are federally-listed as threatened under the ESA. Therefore, these two stocks are granted protection under both the ESA and MMPA, while the remaining three stocks are only protected by the MMPA (at the federal level; state management may also apply).

Figure 1. Distribution (approximations of population centers) of sea otter stocks in the U.S. (SW = Southwest Alaskan; SC = Southcentral Alaskan; SE = Southeast Alaskan; WA = Washington, SCA = Southern/Californian)

While the MMPA and ESA are important federal laws, I would be remiss if I didn’t mention the important role that state laws and state agencies have in managing sea otters. According to the MMPA and ESA, if a state develops and maintains a conservation or recovery program with protections consistent with the standards and policies of the MMPA and/or ESA, then the Service may transfer management authority over to the state1,2. However, typically, the Service has opted to manage any stocks listed under the ESA, while states manage all other stocks not listed under the ESA.

Sea otter management in the states of Washington and California is a clear example of this dichotomy. The Washington sea otter stock is not listed under the ESA, and is therefore, managed by the Washington Department of Fish and Wildlife (WDFW), which developed the stock’s recovery plan[3]. In contrast, sea otters along the California coast are listed as threatened under the ESA, and the Service primarily manages the stock’s recovery[4].

Interestingly, sea otter management in Alaska is an exception to this rule. The Southeast and Southcentral sea otter stocks are not listed under the ESA, yet are still managed by the Service. However, the state recognizes sea otters as a species of greatest conservation need in the state’s Wildlife Action Plan, which acts as a recommendation framework for the management and protection of important species and ecosystems[5]. Therefore, even though the state is not the primary management authority for sea otters by law, they still play a role in protecting Alaskan sea otter populations through this action plan.

Table 1. Federal and state listing status of all sea otter stocks within U.S. coastal waters.

States have also implemented their own laws for protecting at-risk species. For instance, while the Washington sea otter stock is not listed under the ESA, it is listed as endangered under Washington state law4. This example raises an important example demonstrating that even if a stock isn’t federally-listed, it may still be protected on the state level, and is always protected under the MMPA. Therefore, if the federal and state listing status do not match, which is the case for most sea otter stocks in the U.S. (Table 1.), the stock still receives management protection at some level.

So why does this matter?

Each of the previously mentioned laws are prohibitive in nature, where the objectives are to prevent and discourage activities which may harm the stock of interest. Yet, agencies may grant exceptions – in the form of permits – for activities, such as scientific research, translocations, commercial/recreational fisheries operations, etc. The permit approval process will oftentimes depend on: (1) the severity or likelihood of that action to harm the species, (2) the species’ federal and state listing status, and (3) the unique approval procedures enforced by the agency. Activities that are perceived to have a high likelihood of harming a species, or involve a species that’s listed under the ESA, will likely require a longer and more arduous approval process.

A sea otter release in Monterey Bay, California. Source: Monterey Bay Aquarium Newsroom.

Understanding these various approval processes is vitally important for our work on the potential reintroduction of sea otters to Oregon because such an effort will no doubt require many permits and a thoughtful permit approval process. Each agency may have their own set of permits, administrative procedures, and approval processes. Therefore, it behooves us to have a clear understanding of these various processes relative to the state, agency, or stock involved. If, hypothetically, a stock is determined as a suitable candidate for reintroduction into Oregon waters, having this understanding will allow us to determine where our research can best inform the effort, what types of information and data are needed to inform the process, and to which agency or stakeholders we must communicate our research.

 

References:

[1] Marine Mammal Protection Act of 1972

[2] Endangered Species Act of 1973

[3] State of Washington. 2004. Sea Otter Recovery Plan. Washington Department of Fish and Wildlife: Wildlife Program

[4] U.S. Fish & Wildlife Service. 2003. Final Revised Recovery Plan for the Southern Sea Otter (Enydra lutris nereis).

[5] Alaska Department of Fish and Game. 2015. Alaska wildlife action plan. Juneau.

 

The Land of Maps and Charts: Geospatial Ecology

By Alexa Kownacki, Ph.D. Student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

I love maps. I love charts. As a random bit of trivia, there is a difference between a map and a chart. A map is a visual representation of land that may include details like topology, whereas a chart refers to nautical information such as water depth, shoreline, tides, and obstructions.

Map of San Diego, CA, USA. (Source: San Diego Metropolitan Transit System)
Chart of San Diego, CA, USA. (Source: NOAA)

I have an intense affinity for visually displaying information. As a child, my dad traveled constantly, from Barrow, Alaska to Istanbul, Turkey. Immediately upon his return, I would grab our standing globe from the dining room and our stack of atlases from the coffee table. I would sit at the kitchen table, enthralled at the stories of his travels. Yet, a story was only great when I could picture it for myself. (I should remind you, this was the early 1990s, GoogleMaps wasn’t a thing.) Our kitchen table transformed into a scene from Master and Commander—except, instead of nautical charts and compasses, we had an atlas the size of an overgrown toddler and salt and pepper shakers to pinpoint locations. I now had the world at my fingertips. My dad would show me the paths he took from our home to his various destinations and tell me about the topography, the demographics, the population, the terrain type—all attribute features that could be included in common-day geographic information systems (GIS).

Uncle Brian showing Alexa where they were on a map of Maui, Hawaii, USA. (Photo: Susan K. circa 1995)

As I got older, the kitchen table slowly began to resemble what I imagine the set from Master and Commander actually looked like; nautical charts, tide tables, and wind predictions were piled high and the salt and pepper shakers were replaced with pencil marks indicating potential routes for us to travel via sailboat. The two of us were in our element. Surrounded by visual and graphical representations of geographic and spatial information: maps. To put my map-attraction this in even more context, this is a scientist who grew up playing “Take-Off”, a board game that was “designed to teach geography” and involved flying your fleet of planes across a Mercator projection-style mapboard. Now, it’s no wonder that I’m a graduate student in a lab that focuses on the geospatial aspects of ecology.

A precocious 3-year-old Alexa, sitting with the airplane pilot asking him a long list of travel-related questions (and taking his captain’s hat). Photo: Susan K.

So why and how did geospatial ecology became a field—and a predominant one at that? It wasn’t that one day a lightbulb went off and a statistician decided to draw out the results. It was a progression, built upon for thousands of years. There are maps dating back to 2300 B.C. on Babylonian clay tablets (The British Museum), and yet, some of the maps we make today require highly sophisticated technology. Geospatial analysis is dynamic. It’s evolving. Today I’m using ArcGIS software to interpolate mass amounts of publicly-available sea surface temperature satellite data from 1981-2015, which I will overlay with a layer of bottlenose dolphin sightings during the same time period for comparison. Tomorrow, there might be a new version of software that allows me to animate these data. Heck, it might already exist and I’m not aware of it. This growth is the beauty of this field. Geospatial ecology is made for us cartophiles (map-lovers) who study the interdependency of biological systems where location and distance between things matters.

Alexa’s grandmother showing Alexa (a very young cartographer) how to color in the lines. Source: Susan K. circa 1994

In a broader context, geospatial ecology communicates our science to all of you. If I posted a bunch of statistical outputs in text or even table form, your eyes might glaze over…and so might mine. But, if I displayed that same underlying data and results on a beautiful map with color-coded symbology, a legend, a compass rose, and a scale bar, you might have this great “ah-ha!” moment. That is my goal. That is what geospatial ecology is to me. It’s a way to SHOW my science, rather than TELL it.

Would you like to see this over and over again…?

A VERY small glimpse into the enormous amount of data that went into this map. This screenshot gave me one point of temperature data for a single location for a single day…Source: Alexa K.

Or see this once…?

Map made in ArcGIS of Coastal common bottlenose dolphin sightings between 1981-1989 with a layer of average sea surface temperatures interpolated across those same years. A picture really is worth a thousand words…or at least a thousand data points…Source: Alexa K.

For many, maps are visually easy to interpret, allowing quick message communication. Yet, there are many different learning styles. From my personal story, I think it’s relatively obvious that I’m, at least partially, a visual learner. When I was in primary school, I would read the directions thoroughly, but only truly absorb the material once the teacher showed me an example. Set up an experiment? Sure, I’ll read the lab report, but I’m going to refer to the diagrams of the set-up constantly. To this day, I always ask for an example. Teach me a new game? Let’s play the first round and then I’ll pick it up. It’s how I learned to sail. My dad described every part of the sailboat in detail and all I heard was words. Then, my dad showed me how to sail, and it came naturally. It’s only as an adult that I know what “that blue line thingy” is called. Geospatial ecology is how I SEE my research. It makes sense to me. And, hopefully, it makes sense to some of you!

Alexa’s dad teaching her how to sail. (Source: Susan K. circa 2000)
Alexa’s first solo sailboat race in Coronado, San Diego, CA. Notice: Alexa’s dad pushing the bow off the dock and the look on Alexa’s face. (Source: Susan K. circa 2000)
Alexa mapping data using ArcGIS in the Oregon State University Library. (Source: Alexa K circa a few minutes prior to posting).

I strongly believe a meaningful career allows you to highlight your passions and personal strengths. For me, that means photography, all things nautical, the great outdoors, wildlife conservation, and maps/charts.  If I converted that into an equation, I think this is a likely result:

Photography + Nautical + Outdoors + Wildlife Conservation + Maps/Charts = Geospatial Ecology of Marine Megafauna

Or, better yet:

? + ⚓ + ? + ? + ? =  GEMM Lab

This lab was my solution all along. As part of my research on common bottlenose dolphins, I work on a small inflatable boat off the coast of California (nautical ✅, outdoors ✅), photograph their dorsal fin (photography ✅), and communicate my data using informative maps that will hopefully bring positive change to the marine environment (maps/charts ✅, wildlife conservation✅). Geospatial ecology allows me to participate in research that I deeply enjoy and hopefully, will make the world a little bit of a better place. Oh, and make maps.

Alexa in the field, putting all those years of sailing and chart-reading to use! (Source: Leila L.)

 

Living the Dream – life as a marine mammal observer

By Florence Sullivan, MSc.

Living the dream as a marine mammal observer onboard the R/V Bell Shimada Photo credit: Dave Jacobsen

I first learned that “Marine Mammal Observer” was a legitimate career field during the summer after my junior year at the University of Washington.  I had the good fortune to volunteer for the BASIS fisheries-oceanography survey onboard the R/V Oscar Dyson where I met two wonderful bird observers who taught me how to identify various pelagic bird species and clued me in to just how diverse the marine science job market can be. After the cruise, younger Florence went off with an expanded world view and a small dream that maybe someday she could go out to sea and survey for marine mammals on a regular basis (and get paid for it?!).  Eight years later, I am happy to report that I have just spent the last week as the marine mammal observer on the North California Current Survey on the Dyson’s sister ship, the R/V Bell M. Shimada.  While we may not have seen as many marine mammals as I would have liked, the experience has still been everything younger Florence hoped it would be.

Finally leaving port a few days behind schedule due to stormy weather! photo credit: Florence Sullivan

If you’ve ever wondered why the scientists in your life may refer to summer as “field work season”, it’s because attempting to do research outside in the winter is an exercise in frustration, troubleshooting, and flexibility. Case in point; this cruise was supposed to sail away from port on the 24th of February, but did not end up leaving until the 27th due to bad weather.  This weather delay meant that we had to cut some oceanographic stations we would like to have sampled, and even when we made it out of the harbor, the rough weather made it impossible to sample some of the stations we still had left on our map.  That being said, we still got a lot of good work done!

The original station map. The warm colors are the west coast of the US, the cold colors are the ocean, and the black dots are planned survey stations

The oceanographers were able to conduct CTD casts at most planned stations, as well as sample the water column with a vertical zooplankton net, a HAB net (for looking for the organisms that cause Harmful Algal Blooms),  and a Bongo Net (a net that specializes in getting horizontal samples of the water column).  When it wasn’t too windy, they were also able to sample with the Manta net (a net specialized for surface sampling – it looks like a manta ray’s mouth) and at certain near-shore stations they did manage to get some bottom beam trawls in to look at the benthic community of fishes and invertebrates.  All this was done while dodging multitudes of crab pots and storm fronts.  The NOAA corps officers who drive the boat, and the deck crew who handle all the equipment deployments and retrievals really did their utmost to make sure we were able to work.

Stormy seas make for difficult sampling conditions! photo credit: Florence Sullivan

For my part, I spent the hours between stations searching the wind-tossed waves for any sign of marine mammals. Over the course of the week, I saw a few Northern fur seals, half a dozen gray whales, and a couple of unidentified large cetaceans.  When you think about the productivity of the North Pacific Ecosystem this may not seem like very much.  But remember, it is late winter, and I do not have x-ray vision to see through the waves.  It is likely that I missed a number of animals simply because the swell was too large, and when we calculate our “detection probability” these weather factors will be taken into account. In addition, many of our local marine mammals are migrators who might be in warmer climates, or are off chasing different food sources at the moment.  In ecology, when you want to know how a population of animals is distributed across a land- or sea-scape, it is just as important to understand where the animals are NOT as where they ARE. So all of this “empty” water was very important to survey simply because it helps us refine our understanding of where animals don’t want to be.  When we know where animals AREN’T we can ask better questions about why they occur where they ARE.

Black Footed Albatross soars near the boat. Photo credit: Florence Sullivan

Notable species of the week aside from the marine mammals include Laysan and Black Footed Albatrosses, a host of Vellella vellella (sailor by the wind hydroid colonies) and the perennial favorite of oceanographers; the shrinking Styrofoam cup.  (See pictures)

We sent these styrofoam cups down to 1800 meters depth. The pressure at those depths causes all the air to escape from the styrofoam, and it shrinks! This is a favorite activity of oceanographers to demonstrate the effects on increased pressure!

These sorts of interdisciplinary cruises are quite fun and informative to participate in because we can build a better picture of the ecosystem as a whole when we use a multitude of methods to explore it.  This strength of cooperation makes me proud to add my little piece to the puzzle. As I move forward in life, whether I get to be the marine mammal observer, the oceanographer, or perhaps an educator, I will always be glad to contribute to collaborative research.

 

How important are foundational, novel and review papers?

By Leila Lemos, PhD Student

As I wrote in my last blog post, I am in the process of studying for my preliminary exams that will happen in late March (written exams) and late April (oral exam).

My committee members provided me with reading lists of material they thought was important for me to know in order for me to become a PhD candidate. This will serve as the basis for my dissertation research, and provides the framework for how my contribution will advance the field. In the last month, I have been reading many, many articles, book chapters, theses, etc. to build this foundation.

One of the first steps was to organize all of the readings for my prelims on
a big board that would help me visualize what has been done and
what is still missing for each of the committee members

 

The material I am reading is a mixture of foundational and novel material, which are equally important. Foundational articles tell us about the origin of a specific field or theme, and help me to understand fundamental concepts and theories. It is really interesting to see what the pioneer researchers in the field first thought and how they tested their hypotheses many years ago. It is also remarkable to read novel papers and see how these foundational ideas have evolved and developed into new hypotheses, leading to new studies and experiments which push the boundaries of what we already know.

Review papers can also give a sense of this timeline by compiling studies on a particular topic. By assembling all of the available findings in my field, it becomes clear what questions remain unanswered, justifying the goals of my research, and establishing the project’s theoretical and methodological framework.

In my PhD project we are attempting to address some of the unanswered questions related to stress responses in baleen whales. Reading about other studies, their results, and the diverse techniques that have been applied to other taxa makes me really excited about what I can still incorporate in the project.

Source: http://binapatel.me/2017/05/25/literature-review-citation-
tracing-concept-saturation-results-mind-mapping/

 

At the end of my PhD, if we are able to answer our proposed questions, we will have contributed to advancing the field of knowledge, and we will be able to apply our results to the conservation and management of baleen whales in nearshore coastal ecosystems.

The more I read the content proposed by my committee members, the more I find connections between my PhD project, its aims, and the title I proposed for myself as being a “Conservation Physiologist”. Being a Conservation Physiologist is exactly what I want to be, during my PhD, and in the future.

 

 

 

Do I have the time?

By Rachael Orben PhD., Research Associate in the Seabird Oceanography Lab and GEMM Lab

So, there is something called work-life balance. I am still trying to find mine.

As an undergraduate it was easy. I sailed a lot and my grades suffered. In hindsight that was the best choice I could have made.  I learned to sail, spent time on the water and in the end, I think I turned out ok. Following that I spent ~7 years working as a field technician in remote, stunningly beautiful places, with lots of seabirds. I would sum these years up as having very little life balance with lots of experience.

From there I started grad school. At age 29, I relearned how to live in a town and bought my first car. I spent 5.5 years in grad school, but 14 months of this time were spent in the field (not all for my PhD research). During the last phase of my PhD I was often too mentally exhausted on the weekends to even consider trying to write or to analyze data.  I tracked my working hours with RescueTime and I found that after a weekend at play my Monday at work was often very focused and productive. Then through the week my productivity would drop.

That seemed promising. Playing more equaled more efficient work hours. The tales are true.

And then I started post doc life.  A new town, more rain, and more projects that come with deadlines. For the most part, my attempts for a work-life balance went out the window as I adjusted to the new locale. I still do field work and within that experience I can catch my academic breath – while working just as hard.

Evening on High Bluffs, St. George AK

One can read ad nauseam about struggles academic scientists have balancing work and life. There is lots of sage advice out there (e.g. here) and dismay with a system that asks so much of a person (here). As I continue on this career path I know that demands on my time will only become more and more frequent. There is a part of me that likes the idea of curling up on a rainy Saturday morning and crunching out some data analysis even though in the long run this probably isn’t a good approach. And maybe that is the problem – I love most of what I do!

For now, I am still learning. What do I focus on? What do I spend my time on? How do I meet deadlines without a dose of panic? How do I restrain my growing to-do list?

**In order to make sure that I didn’t over or under achieve on this blog post I asked the internet ‘how long should a blog post be?’  It turns out the answers are varied.  But somewhere between 700 and 1,600 words is a good target. I made it to 488.  Today there is a dog that wants a walk, a talk to be written, a manuscript to revise, dinner to cook…

Walking along the Oregon Coast.

 

Grad School: Nothing Lasts, Nothing is Perfect, Nothing is Finished.

By Florence Sullivan, MSc

Last week, I attended the Seattle Garden Show with my mom and a friend of hers.  We particularly enjoyed the West Seattle Nursery’s entry that was intended to reflect on the idea that “Nothing Lasts, Nothing is Perfect, and Nothing is Finished.”  My mom and her friend proceeded to articulate a feeling I think many of us have struggled with.  Not quite “imposter syndrome” because the feeling is not limited to your job, it pervades the whole human experience. Rather, we talked about the idea that as a child, you have an impression that adults have everything figured out in life, but as you grow older, you realize that everyone is just muddling along as best they can. The most important take-away for me in listening to two late-middle-age women have this conversation was: the feeling of being unprepared never goes away, but you have to tackle life head on anyways.

When I finally finished my master’s degree, a similar feeling of ‘what do I do now?!’ caught me by surprise. I was fully cognizant of all the hard work I had done, but my mentally and emotionally exhausted brain could no longer compute how this accomplishment translated to real world skills. I could no longer see the whole of my work, I could only stress out about the bits that I felt were weak or could have been done better.  I was lost in that insidious trap of thinking that because I felt like I still had so much to learn, that my peers had their lives and their research figured out so much more effectively than my own. Time and distance, counseling, and listening to many conversations like my mom’s, helped me to break away from this trap and remember that “Nothing Lasts [Grad school took 3 years], Nothing is Perfect [My work does not need to be perfect in order to matter], and Nothing is Finished [I will never be done learning]”.

Before I moved away from the lab, I was asked to compile my institutional knowledge into a “How to” guide for new GEMM Lab members.  It really does cover a wide range of topics.  There are tips about computer log-ons, where to find certain administrative paperwork and when to fill it out, how to make a post on this blog, protocols for photo-ID work and other routine lab tasks, and even some favorite recipes for lab meetings. Setting this guide up was another helpful step on my journey to remember how much I have learned in the last 3 years, and how much I am capable of contributing to a group.

Team Ro-buff-stus in August 2017.
Team Ro-buff-stus in 2016
Our team name is derived from the scientific name of the gray whale: E. robustus, and the colorful “buff” scarves you can see us wearing on most days. 2015

I’m now actively job hunting, and while this has been stressful, it has also been strangely encouraging as I reframe the variety of skills I picked up in grad school and realize just how much is hidden in that new line on my resume. There are so many common application bullet points that I can answer with confidence. Yes! I have teaching and leadership experience because I trained and supervised 3 generations of interns in the gray whale foraging ecology project. Yes! I have data processing and analysis experience through my classwork and my successfully defended thesis.  Yes! I have scientific writing experience – one of my thesis chapters has been accepted for publication in the Journal of Wildlife Management.  With every Yes! my confidence grows, and I get more excited to start the newest chapter in my life.  I recognize that many of my applications will be rejected, because there are many other qualified applicants out there, but I will keep trying, because Nothing lasts [The job search is temporary], Nothing is Perfect [I do not need to be perfect to get the job], and Nothing is Finished [There will always be room for me to grow].

Moving Day! The GEMM Lab helps Kelly and Florence pack their house.

I am incredibly thankful to everyone who supported my journey.  My advisor Leigh, has been a fabulous mentor in the best sense of the word from day one.  My lab mates Amanda, Rachael, Dawn, Solene, Leila, Erin, Alexa, and Dom have been excellent confidantes, cheerleaders, and sources of inspiration.  My husband, Kelly made sure that I always had a cup of tea, a warm meal, and a hug to keep me going. My interns, Sarah, Cricket, Justin, Kelli, Catherine, Cathryn, Maggie, Nathan and Quince made my field work both possible and enjoyable.  My family and friends at home kept me grounded even at a distance, and my Corvallis contra dancing community reminds me to dance my cares away, because nothing lasts, nothing is perfect, and nothing is finished.

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).

Coastal oceanography takes patience

Joe Haxel, Acoustician, Assistant Professor, CIMRS/OSU

Greetings GEMM Lab blog readers. My name is Joe Haxel and I’m a close collaborator with Leigh and other GEMM lab members on the gray whale ecology, physiology and noise project off the Oregon coast. Leigh invited me for a guest blog appearance to share some of the acoustics work we’ve been up to and as you’ve probably guessed by now, my specialty is in ocean acoustics. I’m a PI in NOAA’s Pacific Marine Environmental Laboratory’s Acoustics Program and OSU’s Cooperative Institute for Marine Resources Studies where I use underwater sound to study a variety of earth and ocean processes.

As a component of the gray whale noise project, during the field seasons of 2016 and 2017 we recorded some of the first measurements of ambient sound in the shallow coastal waters off Oregon between 7 and 20 meters depth. In the passive ocean acoustics world this is really shallow, and with that comes all kinds of instrument and logistical challenges, which is probably one of the main reasons there is little or no acoustic baseline information in this environment.

For instance, one of the significant challenges is rooted in the hydrodynamics surrounding mobile recording systems like the drifting hydrophone we used during the summer field season in 2016 (Fig 1). Decoupling motion of the surface buoy (e.g., caused by swell and waves) from the submerged hydrophone sensor is critical, and here’s why. Hydrophones convert pressure fluctuations at the sensor/ water interface to a calibrated voltage recorded by a logging system. Turbulence resulting from moving the sensor up and down in the water column with surface waves introduces non-acoustic pressure changes that severely contaminate the data for noise level measurements. Vertical and horizontal wave motions are constantly acting on the float, so we needed to engineer compliance between the surface float and the suspended hydrophone sensor to decouple these accelerations. To overcome this, we employed a couple of concepts in our drifting hydrophone design. 1) A 10 cm diameter by 3 m long spar buoy provided floatation for the system. Spar buoys are less affected by wave motion accelerations compared to most other types of surface floatation with larger horizontal profiles and drag. 2) A dynamic shock cord that could stretch up to double its resting length to accommodate vertical motion of the spar buoy; 3) a heave plate that significantly reduced any vertical motion of the hydrophone suspended below it. This was a very effective design, and although somewhat cumbersome in transport with the RHIB between deployment sites, the acoustic data we collected over 40 different drifts around Newport and Port Orford in 2016 was clean, high quality and devoid of system induced contamination.

Figure 1. The drifting hydrophone system used for 40 different drifts recording ambient noise levels in 7-20 m depths in the Newport and Port Orford, OR coastal areas.

 

 

 

 

 

 

 

 

 

 

 

 

Spatial information from the project’s first year acoustic recordings using the drifting hydrophone system helped us choose sites for the fixed hydrophone stations in 2017. Now that we had some basic information on the spatial variability of noise within the study areas we could focus on the temporal objectives of characterizing the range of acoustic conditions experienced by gray whales over the course of the entire foraging season at these sites in Oregon. In 2017 we deployed “lander” style instrument frames, each equipped with a single, omni-directional hydrophone custom built by Haru Matsumoto at our NOAA/OSU Acoustics lab (Fig. 2). The four hydrophone stations were positioned near each of the ports (Yaquina Bay and Port Orford) and in partnership with the Oregon Department of Fish and Wildlife Marine Reserves program in the Otter Rock Marine Reserve and the Redfish Rocks Marine Reserve. The hydrophones were programmed on a 20% duty cycle, recording 12 minutes of every hour at 32 kHz sample rate, providing spectral information in the frequency band from 10 Hz up to a 13 kHz.

Figure 2. The hydrophone (black cylinder) on its lander frame ready for deployment.

Here’s where the story gets interesting. In my experience so far putting out gear off the Oregon coast, anything that has a surface expression and is left out for more than a couple of weeks is going to have issues. Due to funding constraints, I had to challenge that theory this year and deploy 2 of the units with a surface buoy. This is not typically what we do with our equipment since it usually stays out for up to 2 years at a time, is sensitive, and expensive. The 2 frames with a surface float were going to be deployed in Marine Reserves far enough from the traffic lanes of the ports and in areas with significantly less traffic and presumably no fishing pressure.  The surface buoy consisted of an 18 inch diameter hard plastic float connected to an anchor that was offset from the instrument frame by a 150 foot weighted groundline. The gear was deployed off Newport in June and Port Orford in July. What could go wrong?

After monthly buoy checks by the project team, including GPS positions, and buoy cleanings my hopes were pretty high that the surface buoy systems might actually make it through the season with recoveries scheduled in mid-October. Had I gambled and won? Nope. The call came in September from Leigh that one of the whale watching outfits in Depoe Bay recovered a free floating buoy matching ours. Bummer. Alternative recovery plans initiated and this is where things began to get hairy. Fortunately, we had an ace in our back pocket. We have collaborators at the Oregon Coast Aquarium (OCA) who have a top-notch research diving team led by Jim Burke. In the last week of October, they performed a successful search dive on the missing unit near Gull Rock and attached a new set of floats directly to the instrument frame. The divers were in the water for a short 20 minutes thanks to the good series of marks recorded during the buoy checks throughout the summer (Fig. 3).

Figure 3. OCA divers, Jenna and Doug, heading out for a search dive to locate and mark the Gull Rock hydrophone lander.

 

 

 

 

 

We had surface marker floats on the frame, but there was a new problem. Video taken by Jenna and Doug from the OCA dive team revealed the landers were pretty sanded in from a couple of recent October storms (Fig. 4). Ugghhh!

Figure 4. Sanded in lander at Gull Rock. Notice the sand dollars and bull kelp wrapped on the frame.

Alternative recovery plan adjustment: we’re gonna need a diver assisted recovery with 2 boats. One to bring a dive team to air jet the sand out away from the legs of the frame and another larger vessel with pulling power to recover the freed lander. Enter the R/V Pacific Surveyor and Capt. Al Pazar. Al, Jim and I came up with a new recovery plan and only needed a decent weather window of a few hours to get the job done. Piece of cake in November off the Oregon coast, right?

The weather finally cooperated in early December in-line with the OCA dive team and R/V Pacific Surveyor’s availability. The 2 vessels and crew headed up to Gull Rock for the first recovery operation of the day. At first we couldn’t locate the surface floats. Oh no. It seemed the rough fall/ winter weather and high seas since late October were too much for the crab floats? As it turns out, we eventually found the floats eastward about 200 m but couldn’t initially see them in the glare and whitecapping conditions that morning. The lander frame had broken loose from its weakened anchor legs in the heavy weather (as it was designed to do through an Aluminum/ Stainless Steel galvanic reaction over time) and rolled or hopped eastward by about 200 m (Fig. 5). Oh dear!

Figure 5. A hydrophone lander after recovery. Notice all but 1 of the concrete anchor legs missing from the recovered lander and the amount of bio-fouling on the hydrophone (compared to Figure 2).

 

 

 

 

 

 

Thankfully, the hydrophone was well protected, and no air jetting was required. With OCA divers out of the water and clear, the Pacific Surveyor headed over to the floats and easily pulled the lander frame and hydrophone on board (Fig. 6). Yipee!

On to the next hydrophone station. This station, deployed ~ 800 m west of the south reef off of South Beach near the Yaquina Bay port entrance. It was deployed entirely subsurface and was outfitted with an acoustic release transponder that I could communicate with from the surface and command to release a pop-up messenger float and line for eventual recovery of the instrument frame. Once on station, communication with the release was established easily (a good start) and we began ranging and moving the OCA vessel Gracie Lynn in to a position within about 2 water depths of the unit (~40 m). I gave the command to the transponder and the submerged release confirmed it was free of its anchor and heading for the surface, but it never made it. Uh oh. Turns out this lander had also broke free of its anchored legs and rolled/ hopped 800 m eastward until it was pinned up against the boulder structure of the south reef. Amazingly, OCA divers Jenna and Doug located the messenger float ~ 5 m below the surface and the messenger line had been fouled by the rolling frame so it could not reach the surface. They dove down the messenger line and attached a new recovery line to the lander frame and the Pacific Surveyor hauled up the frame and hydrophone in-tact (Fig. 6). Double recovery success!

Figure 6. R/V Pacific Surveyor recovering hydrophone landers off Gull Rock and South Beach.

The hydrophone data from both systems looks outstanding and analysis is underway. This recovery effort took a huge amount of patience and the coordination of 3 busy groups (NOAA/OSU, OCA, Capt. Al). Thanks to these incredible collaborations and some heroic diving from Jim Burke and his OCA dive team, we now have a unique and unprecedented shallow water passive acoustic data set from the energetic waters off the Oregon coast.

So that’s some of the story from the 2016 and 2017 field season acoustic point of view. I’ll save the less exciting, but equally successful instrument recoveries from Port Orford for another time.

Can we talk about how cool sea otters are?

By Dominique Kone, Masters Student in Marine Resource Management

A couple of months ago, I wrote a blog introducing our new project, and my thesis, on the potential to reintroduce sea otters to the Oregon coast. In that blog, I expressed that in order to develop a successful reintroduction plan, scientists and managers need to have a sound understanding of sea otter ecology and the current state of Oregon’s coastal ecosystems. As a graduate student conducting a research-based thesis in a management program, I’m constantly fretting over the applicability of my research to inform decision-making processes. However, in the course of conducting my research, I sometimes forget just how COOL sea otters are. Therefore, in this blog, I wanted to take the opportunity to nerd out and provide you with my top five favorite facts about these otterly adorable creatures.

Photo Credit: Point Lobos Foundation

Without further ado, here are my top five favorite facts about sea otters:

  1. Sea otters eat a lot. Previous studies show that an individual sea otter eats up to 30% of its own body weight in food each day[1][2]. With such high caloric demands, sea otters spend a great deal of their time foraging the seafloor for a variety of prey species, and have been shown to decrease prey densities in their local habitat significantly. Sea otters are famously known for their taste for sea urchins. Yet, these voracious predators also consume clams, sea stars, crabs, and a variety of other small invertebrate species[3][4].

    Photo Credit: Katherine Johns via www.listal.com
  2. Individuals are specialists, but can change their diet. Sea otters typically show individual foraging specialization – which means an individual predominantly eats a select few species of prey. However, this doesn’t mean an otter can’t switch or consume other types of prey as needed. In fact, while individuals tend to be specialists, on a population or species level, sea otters are actually generalist predators[5][6]. Past studies that looked at the foraging habits of expanding sea otter populations show that as populations expand into unoccupied territory, they typically eat a limited number of prey. But as populations grow and become more established, the otters will start to diversify their diet, suggesting intra-specific competition[3][7].
  3. Sea otters exert a strong top-down force. Top-down forcing is one of the most important concepts we must acknowledge when discussing sea otter ecology. With top-down forcing, consumers at the top of the food chain depress the trophic level on which they feed, and this feeding indirectly increases the abundance of the next lower trophic level, resulting in a cascading effect[8]. The archetype example of this phenomenon is the relationship between sea otters, sea urchins, and kelp forests. This relationship goes as follows: sea otters consume sea urchin, and sea urchins graze on kelp. Therefore, sea otters reduce sea urchin densities by direct predation, thereby mediating grazing pressure on kelp. This indirect effect allows kelp to grow more abundantly, which is why we often see relatively productive kelp forests when sea otters are present[9]. This top-down forcing also has important implications for the whole ecosystem, as I’ll explain in my next fact.

    Pictured: sea urchin dominated seascape in habitat without sea otters. Photo Credit: BISHOPAPPS via Ohio State University.
  4. Sea otters help restore ecosystems, and associated ecosystem services. In kelp habitat where sea otters have been removed, we often see high densities of sea urchins and low biomasses of kelp. In this case, sea urchins have no natural predators to keep their populations in check and therefore completely decimate kelp forests. However, what we’ve learned is that when sea otters “reclaim” previously occupied habitats or expand into unoccupied territory, they can have remarkable restorative effects because their predation on sea urchins allows for the regrowth of kelp forest[10]. Additionally, with the restoration of key ecosystems like kelp forests, we can see a variety of other indirect benefits – such as increased biodiversity, refuge for fish nurseries and commercially-important species, and carbon sequestration[11][12][13]. The structure of nearshore ecosystems and communities change drastically with the addition or removal of sea otters, which is why they’re often referred to as keystone species.

    Photo Credit: University of California, Santa Barbara.
  5. Sea otters are most often associated with coastal kelp forests, but they can also exist in other types of habitats and ecosystems. In addition to kelp dominated ecosystems, sea otters are known to use estuaries and bays, seagrass beds, and swim over a range of bottom substrates[14][15]. As evidenced by previous studies, sea otters exert similar top-down forces in non-kelp ecosystems, as they do within kelp forests. One study found that sea otters also had restorative effects on seagrass beds within estuaries, where they consumed different types of prey (i.e., crabs instead of urchins), demonstrating that sea otters play a significant keystone role in seagrass habitats as well [12]. Findings such as these are vitally important to understanding (1) where sea otters are capable of living relative to habitat characteristics, and (2) how recovering or expanding sea otter populations may impact ecosystems and habitats in which they don’t currently exist, such as the Oregon coast.
Pictured: sea otter swimming through eel grass at Elkhorn Slough, California. Photo Credit: Kip Evans Photography.

Well, there you have it – my top five favorite facts about sea otters. This list is by no means exhaustive of all there is to know about sea otter ecology, and isn’t enough information to develop an informative reintroduction plan. However, a successful reintroduction plan will rely heavily on these underlying ecological characteristics of sea otters, in addition to the current state of Oregon’s nearshore ecosystems. As someone who constantly focuses on the relationship between scientific research and management and conservation, it’s nice every now and then to take a step back and just simply appreciate sea otters for being, well, sea otters.

References:

[1] Costa, D. P. 1978. The ecological energetics, water, and electrolyte balance of the California sea otter (Enhydra lutris). Ph.D. dissertation, University of California, Santa Cruz.

[2] Reidman, M. L. and J. A. Estes. 1990. The sea otter (Enhydra lutris): behavior, ecology, and natural history. United States Department of the Interior, Fish and Wildlife Service, Biological Report. 90: 1-126.

[3] Laidre, K.L. and R. J. Jameson. 2006. Foraging patterns and prey selection in an increasing and expanding sea otter population. Journal of Mammology. 87(4): 799-807.

[4] Estes, J. A., Jameson, R.J., and B. R. Rhode. 1982. Activity and prey election in the sea otter: influence of population status on community structure. The American Naturalist. 120(2): 242-258.

[5] Tinker, M. T., Costa, D. P., Estes, J. A., and N. Wieringa. 2007. Individual dietary specialization and dive behavior in the California sea otter: using archival time-depth data to detect alternative foraging strategies. Deep-Sea Research Part II. (54):330-342.

[6] Newsome et al. 2009. Using stable isotopes to investigate individual diet specialization in California sea otters (Enhydra lutris nereis). Ecology. 90(4): 961-974.

[7] Ostfeld, R. S. 1982. Foraging strategies and prey switching in the California sea otter. Oecologia. 53(2): 170-178.

[8] Paine, R. T. 1980. Food webs: linkage, interaction strength and community infrastructure. The Journal of Animal Ecology. 49(3): 666-685.

[9] Estes, J. A. and J.F. Palmisano. 1974. Sea otters: their role in structuring nearshore communities. Science. 185(4156): 1058-1060.

[10] Estes, J. A., and D. O. Duggins. 1995. Sea otters and kelp forests in Alaska: generality and variation in a community ecological paradigm. Ecological Monographs. 65(1): 75-100.

[11] Wilmers, C. C., Estes, J. A., Edwards, M., Laidre, K. L., and B. Konar. 2012. Do trophic cascades affect the storage and flux of atmospheric carbon? An analysis of sea otters and kelp forests. Frontiers in Ecology and the Environment. 10(8): 409-415.

[12] Hughes et al. 2014. Recovery of a top predator mediate negative eutrophic effects on seagrass. Proceedings of the National Academy of Sciences. 110(38): 15313-15318.

[13] Lee, L.C., Watson, J. C., Trebilco, R., and A. K. Salomon. Indirect effects and prey behavior mediate interactions between an endangered prey and recovering predator. Ecosphere. 7(12).

[14] Laidre, K. L., Jameson, R. J., Gurarie, E., Jeffries, S. J., and H. Allen. 2009. Spatial habitat use patterns of sea otters in coastal Washington. Journal of Mammalogy. 90(4): 906-917.

[15] Lafferty, K. D., and M. T. Tinker. 2014. Sea otters are recolonizing southern California in fits and starts. Ecosphere. 5(5).