management Archives - Geospatial Ecology of Marine Megafauna Laboratory

Lingering questions on the potential to bring sea otters back to Oregon

By Dominique Kone, Masters Student in Marine Resource Management

By now, I’m sure you’re aware of recent interests to reintroduce sea otters to Oregon. To inform this effort, my research focuses on predicting suitable sea otter habitat and investigating the potential ecological effects if sea otters are reintroduced in the future. This information will help managers gain a better understanding of the potential for sea otters to reestablish in Oregon, as well as how Oregon’s ecosystems may change via top-down processes. These analyses will address some sources of uncertainties of this effort, but there are still many more questions researchers could address to further guide this process. Here, I note some lingering questions I’ve come across in the course of conducting my research. This is not a complete list of all questions that could or should be investigated, but they represent some of the most interesting questions I have and others have in Oregon.

The questions, and our associated knowledge on each of these topics:

Is there enough available prey to support a robust sea otter population in Oregon?

Sea otters require approximately 30% of their own body weight in food every day (Costa 1978, Reidman & Estes 1990). With a large appetite, they not only need to spend most of their time foraging, but require a steady supply of prey to survive. For predators, we assume the presence of suitable habitat is a reliable proxy for prey availability (Redfern et al. 2006). Whereby, quality habitat should supply enough prey to sustain predators at higher trophic levels.

In making these habitat predictions for sea otters, we must also recognize the potential limitations of this “habitat equals prey” paradigm, in that there may be parcels of habitat where prey is unavailable or inaccessible. In Oregon, there could be unknown processes unique to our nearshore ecosystems that would support less prey for sea otters. This possibility highlights the importance of not only understanding how much suitable habitat is available for foraging sea otters, but also how much prey is available in these habitats to sustain a viable otter population in the future. Supplementing these habitat predictions with fishery-independent prey surveys is one way to address this question.

Credit: Suzi Eszterhas via Smithsonian Magazine

How will Oregon’s oceanographic seasonality alter or impact habitat suitability?

Sea otters along the California coast exist in an environment with persistent Giant kelp beds, moderate to low wave intensity, and year-round upwelling regimes. These environmental variables and habitat factors create productive ecosystems that provide quality sea otter habitat and a steady supply of prey; thus, supporting high densities of sea otters. This environment contrasts with the Oregon coast, which is characterized by seasonal changes in bull kelp and wave intensity. Summer months have dense kelp beds, calm surf, and strong upwellings. While winter months have little to no kelp, weak upwellings, and intense wave climates. These seasonal variations raise the question as to how these temporal fluctuations in available habitat could impact the number of sea otters able to survive in Oregon.

In Washington – an environment like Oregon – sea otters exhibit seasonal distribution patterns in response to intensifying wave climates. During calm summer months, sea otters primarily forage along the outer coast, but move into more protected areas, such as the Strait of Juan de Fuca, during winter months (Laidre et al. 2009). If sea otters were reintroduced to Oregon, we may very well observe similar seasonal movement patterns (e.g. dispersal into estuaries), but the degree to which this seasonal redistribution and reduction in foraging habitat could impact sea otter reestablishment and recovery is currently unknown.

In the event of a reintroduction, do northern or southern sea otters have a greater capacity to adapt to Oregon environments?

In the early 1970’s, Oregon’s first sea otter translocation effort failed (Jameson et al. 1982). Since then, hypotheses on the potential ecological differences between northern and southern sea otters have been proposed as potential factors of the failed effort, potentially due to different abilities to exploit specific prey species. Studies have demonstrated that northern and southern sea otters have slight morphological differences – northern otters having larger skulls and teeth than southern otters (Wilson et al. 1991). This finding has created the hypothesis that the northern otter’s larger skull and teeth allow it to consume prey with denser exoskeletons, and thereby can exploit a greater diversity of prey species. However, there appears to be a lack of evidence to suggest larger skulls and teeth translate to greater bite force. Based on morphology alone, either sub-species could be just as successful in exploiting different prey species.

A different direction to address questions around adaptability is to look at similarities in habitat and oceanographic characteristics. Sea otters exist along a gradient of habitat types (e.g. kelp forests, estuaries, soft-sediment environments) and oceanographic conditions (e.g. warm-temperature to cooler sub-Arctic waters) (Laidre et al. 2009, Lafferty et al. 2014). Yet, we currently don’t know how well or quickly otters can adapt when they expand into new habitats that differ from ones they are familiar with. Sea otters must be efficient foragers and need to acquire skills that allow them to effectively hunt specific prey species (Estes et al. 2003). Hypothetically, if we take sea otters from rocky environments where they’ve developed foraging skills to hunt sea urchins and abalones, and place them in a soft-sediment environment, how quickly would they develop new foraging skills to exploit soft-sediment prey species? Would they adapt quickly enough to meet their daily prey requirements?

Credit: Eric Risberg/Associated Press via The Columbian

In Oregon, specifically, how might climate change impact sea otters, and how might sea otters mediate climate impacts?

Climate change has been shown to directly impact many species via changes in temperature (Chen et al. 2011). Some species have specific thermal tolerances, in which they can only survive within a specified temperature range (i.e. maximum and minimum). Once the temperature moves out of that range, the species can either move with those shifting water masses, behaviorally adapt or perish (Sunday et al. 2012). It’s unclear if and how changing temperatures will impact sea otters, directly. However, sea otters could still be indirectly affected via impacts to their prey. If prey species in sea otter habitat decline due to changing temperatures, this would reduce available food for otters. Ocean acidification (OA) is another climate-induced process that could indirectly impact sea otters. By creating chemical conditions that make it difficult for species to form shells, OA could decrease the availability of some prey species, as well (Gaylord et al. 2011).

Interestingly, these pathways between sea otters and climate change become more complex when we consider the potentially mediating effects from sea otters. Aquatic plants – such as kelp and seagrass – can reduce the impacts of climate change by absorbing and taking carbon out of the water column (Krause-Jensen & Duarte 2016). This carbon sequestration can then decrease acidic conditions from OA and mediate the negative impacts to shell-forming species. When sea otters catalyze a tropic cascade, in which herbivores are reduced and aquatic plants are restored, they could increase rates of carbon sequestration. While sea otters could be an effective tool against climate impacts, it’s not clear how this predator and catalyst will balance each other out. We first need to investigate the potential magnitude – both temporal and spatial – of these two processes to make any predictions about how sea otters and climate change might interact here in Oregon.

In Summary

There are several questions I’ve noted here that warrant further investigation and could be a focus for future research as this potential sea otter reintroduction effort progresses. These are by no means every question that should be addressed, but they do represent topics or themes I have come across several times in my own research or in conversations with other researchers and managers. I think it’s also important to recognize that these questions predominantly relate to the natural sciences and reflect my interest as an ecologist. The number of relevant questions that would inform this effort could grow infinitely large if we expand our disciplines to the social sciences, economics, genetics, so on and so forth. Lastly, these questions highlight the important point that there is still a lot we currently don’t know about (1) the ecology and natural behavior of sea otters, and (2) what a future with sea otters in Oregon might look like. As with any new idea, there will always be more questions than concrete answers, but we – here in the GEMM Lab – are working hard to address the most crucial ones first and provide reliable answers and information wherever we can.

References:

Chen, I., Hill, J. K., Ohlemuller, R., Roy, D. B., and C. D. Thomas. 2011. Rapid range shifts of species associated with high levels of climate warming. Science. 333: 1024-1026.

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.

Estes, J. A., Riedman, M. L., Staedler, M. M., Tinker, M. T., and B. E. Lyon. 2003. Individual variation in prey selection by sea otters: patterns, causes and implications. Journal of Animal Ecology. 72: 144-155.

Gaylord et al. 2011. Functional impacts of ocean acidification in an ecologically critical foundation species. Journal of Experimental Biology. 214: 2586-2594.

Jameson, R. J., Kenyon, K. W., Johnson, A. M., and H. M. Wight. 1982. History and status of translocated sea otter populations in North America. Wildlife Society Bulletin. 10(2): 100-107.

Krause-Jensen, D., and C. M. Duarte. 2016. Substantial role of macroalgae in marine carbon sequestration. Nature Geoscience. 9: 737-742.

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

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 Marine Mammalogy. 90(4): 906-917.

Redfern et al. 2006. Techniques for cetacean-habitat modeling. Marine Ecology Progress Series. 310: 271-295.

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.

Sunday, J. M., Bates, A. E., and N. K. Dulvy. 2012. Thermal tolerance and the global redistribution of animals. Nature: Climate Change. 2: 686-690.

Wilson, D. E., Bogan, M. A., Brownell, R. L., Burdin, A. M., and M. K. Maminov. 1991. Geographic variation in sea otters, Ehydra lutris. Journal of Mammalogy. 72(1): 22-36.

Eyes from Space: Using Remote Sensing as a Tool to Study the Ecology of Blue Whales

By Christina Garvey, University of Maryland, GEMM Lab REU Intern

It is July 8^th and it is my 4^th week here in Hatfield as an REU intern for Dr. Leigh Torres. My name is Christina Garvey and this summer I am studying the spatial ecology of blue whales in the South Taranaki Bight, New Zealand. Coming from the east coast, Oregon has given me an experience of a lifetime – the rugged shorelines continue to take my breath away and watching sea lions in Yaquina Bay never gets old. However, working on my first research project has by far been the greatest opportunity and I have learned so much in so little time. When Dr. Torres asked me to contribute to this blog I was unsure of how I would write about my work thus far but I am excited to have the opportunity to share the knowledge I have gained with whoever reads this blog post.

The research project that I will be conducting this summer will use remotely sensed environmental data (information collected from satellites) to predict blue whale distribution in the South Taranaki Bight (STB), New Zealand. Those that have read previous blogs about this research may remember that the STB study area is created by a large indentation or “bight” on the southern end of the Northern Island. Based on multiple lines of evidence, Dr. Leigh Torres hypothesized the presence of an unrecognized blue whale foraging ground in the STB (Torres 2013). Dr. Torres and her team have since proved that blue whales frequent this region year-round; however, the STB is also very industrial making this space-use overlap a conservation concern (Barlow et al. 2018). The increasing presence of marine industrial activity in the STB is expected to put more pressure on blue whales in this region, whom are already vulnerable from the effects of past commercial whaling (Barlow et al. 2018) If you want to read more about blue whales in the STB check out previous blog posts that talk all about it!

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

Figure 2. South Taranaki Bight, New Zealand, our study site outlined by the red box. Kahurangi Point (black star) is the site of wind-driven upwelling system.

The possibility of the STB as an important foraging ground for a resident population of blue whales poses management concerns as New Zealand will have to balance industrial growth with the protection and conservation of a critically endangered species. As a result of strong public support, there are political plans to implement a marine protected area (MPA) in the STB for the blue whales. The purpose of our research is to provide scientific knowledge and recommendations that will assist the New Zealand government in the creation of an effective MPA.

In order to create an MPA that would help conserve the blue whale population in the STB, we need to gather a deeper understanding of the relationship between blue whales and this marine environment. One way to gain knowledge of the oceanographic and ecological processes of the ocean is through remote sensing by satellites, which provides accessible and easy to use environmental data. In our study we propose remote sensing as a tool that can be used by managers for the design of MPAs (through spatial and temporal boundaries). Satellite imagery can provide information on sea surface temperature (SST), SST anomaly, as well as net primary productivity (NPP) – which are all measurements that can help describe oceanographic upwelling, a phenomena that is believed to be correlated to the presence of blue whales in the STB region.

Figure 3. The stars of the show: blue whales. A photograph captured from the small boat of one animal fluking up to dive down as another whale surfaces close by. (Photo credit: L. Torres)

Past studies in the STB showed evidence of a large upwelling event that occurs off the coast of Kahurangi Point (Fig. 2), on the northwest tip of the South Island (Shirtcliffe et al. 1990). In order to study the relationship of this upwelling to the distribution of blue whales, I plan to extract remotely sensed data (SST, SST anomaly, & NPP) off the coast of Kahurangi and compare it to data gathered from a centrally located site within the STB, which is close to oil rigs and so is of management interest. I will first study how decreases in sea surface temperature at the site of upwelling (Kahurangi) are related to changes in sea surface temperature at this central site in the STB, while accounting for any time differences between each occurrence. I expect that this relationship will be influenced by the wind patterns, and that there will be changes based on the season. I also predict that drops in temperature will be strongly related to increases in primary productivity, since upwelling brings nutrients important for photosynthesis up to the surface. These dips in SST are also expected to be correlated to blue whale occurrence within the bight, since blue whale prey (krill) eat the phytoplankton produced by the productivity.

Figure 4. A blue whale lunges on an aggregation of krill. UAS piloted by Todd Chandler.

To test the relationships I determine between remotely sensed data at different locations in the STB, I plan to use blue whale observations from marine mammal observers during a seismic survey conducted in 2013, as well as sightings recorded from the 2014, 2016, and 2017 field studies led by Dr. Leigh Torres. By studying the statistical relationships between all of these variables I hope to prove that remote sensing can be used as a tool to study and understand blue whale distribution.

I am very excited about this research, especially because the end goal of creating an MPA really gives me purpose. I feel very lucky to be part of a project that could make a positive impact on the world, if only in just a little corner of New Zealand. In the mean time I’ll be here in Hatfield doing the best I can to help make that happen.

References:

Barlow DR, Torres LG, Hodge KB, Steel D, Baker CS, Chandler TE, Bott N, Constantine R, Double MC, Gill P, Glasgow D, Hamner RM, Lilley C, Ogle M, Olson PA, Peters C, Stockin KA, Tessaglia-hymes CT, Klinck H (2018) Documentation of a New Zealand blue whale population based on multiple lines of evidence. Endanger Species Res 36:27–40.

Shirtcliffe TGL, Moore MI, Cole AG, Viner AB, Baldwin R, Chapman B (1990) Dynamics of the Cape Farewell upwelling plume, New Zealand. New Zeal J Mar Freshw Res 24:555–568.

Torres LG (2013) Evidence for an unrecognised blue whale foraging ground in New Zealand. New Zeal J Mar Freshw Res 47:235–248.

Should scientists engage in advocacy?

By Dominique Kone, Masters Student in Marine Resource Management

Should scientists engage in advocacy? This question is one of the most debated topics in conservation and natural resource management. Some experts firmly oppose researchers advocating for policy decisions because such actions potentially threaten the credibility of their science. While others argue that with environmental issues becoming more complex, society would benefit from hearing scientists’ opinions and preferences on proposed actions. While both arguments are valid, we must recognize the answer to this question may never be a universal yes or no. As an early-career scientist, I’d like to share some of my observations and thoughts on this topic, and help continue this dialogue on the appropriateness of scientists exercising advocacy.

Policymakers are tasked with making decisions that determine how species and natural resources are managed, and subsequently affect and impact society. Scientists commonly play an integral role in these policy decisions, by providing policymakers with reliable and accurate information so they can make better-informed decisions. Examples include using stock assessments to set fishing limits, incorporating the regeneration capacity of forests into the timing of timber harvest, or considering the distribution of blue whales in permitting seafloor mining projects. Importantly, informing policy with science is very different from scientists advocating on policy issues. To understand these nuances, we must first define these terms.

A scientist considering engaging in policy advocacy. Source: Karen Brey.

According to Merriam-Webster, informing means “to communicate knowledge to” or “to give information to an authority”. In contrast, advocating means “to support or argue for (a cause, policy, etc.)” (Merriam-Webster 2019). People can inform others by providing information without necessarily advocating for a cause or policy. For many researchers, providing credible science to inform policy decisions is the gold standard. We, as a society, do not take issue with researchers supplying policymakers with reliable information. Rather, pushback arises when researchers step out of their role as informants and attempt to influence or sway policymakers to decide in a particular manner by speaking to values. This is advocacy.

Dr. Robert Lackey is a fisheries & political scientist, and one of the prominent voices on this issue. In his popular 2007 article, he explains that when scientists inform policy while also advocating, a conflict of interest is created (Lackey 2007). To an outsider, it can be difficult to distinguish values from scientific evidence when researchers engage in policy discussions. Are they engaging in these discussions to provide reliable information as an honest scientist, or are they advocating for decisions or policies based on their personal preferences? As a scientist, I like to believe most scientists – in natural resource management and conservation – do not engage in policy decisions for their own benefit, and they truly want to see our resources managed in a responsible and sustainable manner. Yet, I also recognize this belief doesn’t negate the fact that when researchers engage in policy discussions, they could advocate for their personal preferences – whether they do so consciously or subconsciously – which makes identifying these conflicts of interest particularly challenging.

Examples of actions scientists take in conducting and reporting research. Actions on the left represent actions of policy advocacy, those on the right do not, and the center is maybe. This graphic was adapted from a policy advocacy graphic from Scott et al. 2007. Source: Jamie Keyes.

It seems much of the unease with researchers exercising advocacy has to do with a lack in transparency about which role the researcher chooses to play during those policy debates. A simple remedy to this dilemma – as Lackey suggested in his paper – could be to encourage scientists to be completely transparent when they are about to inform versus advocate (Lackey 2007). Yet, for this suggestion to work, it would require complete trust in scientists to (1) verbalize and make known whether they’re informing or advocating, and (2) when they are informing, to provide credible and unbiased information. I’ve only witnessed a few scientists do this without ensuing some skepticism, which unfortunately highlights issues around an emerging mistrust of researchers to provide policy-neutral science. This mistrust threatens the important role scientists have played in policy decisions and the relationships between scientists and policymakers.

While much of this discussion has been focused on how researchers and their science are received by policymakers, researchers engaging in advocacy are also concerned with how they are perceived by their peers within the scientific community. When I ask more-senior researchers about their concerns with engaging in advocacy, losing scientific credibility is typically at or near the top of their lists. Many of them fear that once you start advocating for a position or policy decision (e.g. protected areas, carbon emission reduction, etc.), you become known for that one cause, which opens you up to questions and suspicions on your ability to provide unbiased and objective science. Once your credibility as a scientist comes into question, it could hinder your career.

How it sometimes feels when researchers conduct policy-relevant science. Source: Justin DeFreitas.

Conservation scientists are faced with a unique dilemma. They value both biodiversity conservation and scientific credibility. Yet, in some cases, risk or potential harm to a species or ecosystem may outweigh concerns over damage to their credibility, and therefore, may choose to engage in advocacy to protect that species or ecosystem (Horton 2015). Horton’s explanation raises an important point that researchers taking a hands-off approach to advocacy may not always be warranted, and that a researcher’s decision to engage in advocacy will heavily depend on the issue at hand and the repercussions if the researcher does not advocate their policy preferences. Climate change is a great example, where climate scientists are advocating for the use of their science, recognizing the alternative could mean continued inaction on carbon emission reduction and mitigation. [Note: this is called science advocacy, which is slightly different than advocating personal preferences, but this example helps demonstrate my point.]

To revisit the question – should scientists engage in advocacy? Honestly, I don’t have a clear answer, because there is no clear answer. This topic is one that has so many dimensions beyond the few I mentioned in this blog post. In my opinion, I don’t think researchers should have an always yes or always no stance on advocacy. Nor do I think every researcher needs to agree on this topic. A researcher’s decision to engage in advocacy will all depend on context. When faced with this decision, it might be useful to ask yourself the following questions: (1) How much do policymakers trust me? (2) How will my peers perceive me if I choose to engage? (3) Could I lose scientific credibility if I do engage? And (4) What’s at stake if I don’t make my preferences known? Hopefully, the answers to these sub-questions will help you decide whether you should advocate.

References:

Horton, C. C., Peterson, T. R., Banerjee, P., and M. J. Peterson. 2015. Credibility and advocacy in conservation science. Conservation Biology. 30(1): 23-32.

Lackey, R. T. 2007. Science, Scientists, and Policy Advocacy. Conservation Biology. 21(1): 12-17.

Scott et al. (2007). Policy advocacy in science: prevalence, perspectives, and implications for conservation biologists. Conservation Biology. 21(1): 29-35.

Merriam-Webster. 2019. Retrieved from < https://www.merriam-webster.com/ >

Highlights from the 11th Sea Otter Conservation Workshop

By Dominique Kone, Masters Student in Marine Resource Management

I recently attended and presented at the 11^th biennial Sea Otter Conservation Workshop (the Workshop), hosted by the Seattle Aquarium. As the largest sea otter-focused meeting in the world, the Workshop brought together dozens of scientists, managers, and conservationists to share important information and research on sea otter conservation issues. Being new to this community, this was my first time attending the Workshop, and I had the privilege of meeting some of the most influential sea otter experts in the world. Here, I recount some of my highlights from the Workshop and discuss the importance of this meeting to the continued conservation and management of global sea otter populations.

Sea otters represent one of the most successful species recovery stories in history. After facing near extinction at the close of the Maritime Fur Trade in 1911 (Kenyon 1969), they have made an impressive comeback due to intense conservation efforts. The species is no longer in such dire conditions, but some distinct populations are still considered at-risk due to their small numbers and persistent threats, such as oil spills or disease. We still have a ways to go until global sea otter populations are recovered, and collaboration across disciplines is needed for continued progress.

The Workshop provided the perfect means for this collaboration and sharing of information. Attendees were a mixture of scientists, managers, advocacy groups, zoos and aquarium staff, and graduate students. Presentations spanned a range of disciplines, including ecology, physiology, genetics, and animal husbandry, to name a few. On the first day of the Workshop, most presentations focused on sea otter ecology and management. The plenary speaker – Dr. Jim Estes (retired ecologist and University of California, Santa Cruz professor) – noted that one of the reasons we’ve had such success in sea otter recovery is due to our vast knowledge of their natural history and behavior. Much of this progress can be attributed to seminal work, such as Keyon’s 1969 report, which provides an extensive synthesis of several sea otter ecological and behavioral studies (Kenyon 1969). Beginning in the 1970’s, several other ecologists – such as David Duggins, Jim Bodkin, Tim Tinker, and Jim himself – expanded this understanding to complex trophic cascades, individual diet specialization, and population demographics.

Jim Estes and Tim Tinker. Source: Jim Estes.

These ecological studies have played an integral role in sea otter conservation, but other disciplines were and continue to be just as important. As the Workshop continued into the second and third days, presentations shifted their focus to physiology, veterinary medicine, and animal husbandry. Two of these speakers – who have played pivotal roles in these areas – are Dr. Melissa Miller (veterinarian specialist and pathologist with the California Department of Fish & Wildlife) and Dr. Mike Murray (director of veterinary services at the Monterey Bay Aquarium). Dr. Miller presented her years of work on understanding causes of mortality in wild southern sea otters in California. Her research showed that shark predation is a large source of mortality in the southern stock, but cardiac arrest, which has gained less attention, is also a large contributing factor.

Dr. Murray discussed his practice of caring for and studying the biology of captive sea otters. He provided an overview of some of the routine procedures (i.e. full body exams, oral surgeries, and radio transmitter implantation) his team conducts to assess and treat stranded wild otters, so they can be returned to the wild. Both presenters demonstrated how advances in veterinary medicine have helped us better understand the multitude of threats to sea otters in the wild, and what interventive measures can be taken to recover sick or injured otters so they can contribute to wild population recovery. By understanding how these threats are impacting sea otter health on an individual level, we can be better equipped to prevent population-wide consequences.

Dr. Melissa Miller conducting a sea otter necropsy. Source: California Department of Fish & Game.

Throughout the entire Workshop, experts with decades of experience presented their work. Yet, one of the most encouraging aspects of this meeting was that several graduate students also presented their research, including myself. In a way, listening to presenters both early and late in their careers gave us a glimpse into the past and future of sea otter conservation. Much of the work currently being conducted by graduate students addresses some of the most pressing and emerging issues (e.g. shark predation, plastic pollution, and diseases) in this field, but also builds off the great knowledge base acquired by many of those at the Workshop.

Perhaps even more encouraging was the level of collaboration and mentorship between graduate students and seasoned experts. Included in almost every graduate student’s acknowledgement section of their presentations, were the names of several Workshop attendees who either advised them or provided guidance on their research. These presentations were often followed up with further meetings between students and their mentors. These types of interactions really demonstrated how invested the sea otter community is in fostering the next generation of leaders in this field. This “passing of the mantel” is imperative to maintain knowledge between generations and to continue to make progress in sea otter conservation. As a graduate student, I greatly appreciated getting the opportunity to interact with and gain advice from many of these researchers, whom I’ve only read about in articles.

To summarize my experience, it became clear how important this Workshop was to the broader sea otter conservation community. The Workshop provided the perfect venue for collaboration amongst experts, as well as mentorship of upcoming leaders in the field. It’s important to recognize the great progress and strides the community has made already in understanding the complex lives of sea otters. Sea otters have not recovered everywhere. Therefore, we need to continue to acquire knowledge across all disciplines if we are to make progress in the future, especially as new threats and issues emerge. It will take a village.

Literature Cited:

Kenyon, K. W. 1969. The sea otter in the eastern Pacific Ocean. North American Fauna. 68. 352pp.

Understanding sea otter effects through complexity

By Dominique Kone, Masters Student in Marine Resource Management

Species reintroductions are a management strategy to augment the reestablishment or recovery of a locally-extinct or extirpated species into once native habitat. The potential for reestablishment success often depends on the species’ ecological characteristics, habitat requirements, and relationship and effects to other species in the environment[1]. While the science behind species reintroductions is continuously evolving and improving, reintroductions are still inherently risky and uncertain in nature. Therefore, every effort should be made to fully assess ecological factors before a reintroduction takes place. As Oregon considers a potential sea otter reintroduction, understanding these ecological factors is an important piece of my own graduate research.

Sea otters are oftentimes referred to as keystone species because they can have wide-reaching effects on the community structure and function of nearshore marine environments. Furthermore, relative to other marine mammals or top predators, several papers have documented these effects – partially due to the ease in observing their foraging and social behaviors, which typically take place close to shore. In many of these studies, a classic paradigm repeatedly appears: when sea otters are present, prey densities (e.g., sea urchins) are significantly reduced, while macroalgae (e.g., kelp, seagrass) densities are high.

While this paradigm is widely-accepted amongst researchers, a few key studies have also demonstrated that the effects of sea otters may be more variable than we once thought. The paradigm does not necessarily hold true everywhere sea otters exist, or at least not to the same degree. For example, after observing benthic communities along islands with varying sea otter densities in the Aleutian archipelago, Alaska, researchers found that islands with abundant otter populations consistently supported low sea urchin densities and high, yet variable, kelp densities. In contrast, islands without otters consistently had low kelp densities and high, yet variable, urchin densities[2]. This study demonstrates that while the classic paradigm generally held true, the degree to which the ecosystem belonged to one of two dominant states (sea otters, low urchins, and high kelp or no sea otters, high urchins, and low kelp) was less obvious.

This example demonstrates the danger in applying this one-size-fits-all paradigm to sea otter effects. Hence, we want to achieve a better understanding of potential sea otter effects so that managers may anticipate how Oregon’s nearshore environments may be affected if sea otters were to be reintroduced. Yet, how can we accurately anticipate these effects given these potential variations and deviations from the paradigm? Interestingly, if we look to other fields outside ecology, we find a possible solution and tool for tackling these uncertainties: a systematic review of available literature.

Two ecosystem states as predicted by the classic paradigm (left: kelp-dominated; right: urchin-dominated). Source: SeaOtters.com.

For decades, medical researchers have been conducting systematic reviews to assess the efficacy of treatments and drugs by combining several studies to find common findings[3]. These findings can then be used to determine any potential variation between studies (i.e. instances where the results may conflict or differ from one another) and even test the influence and importance of key factors that may be driving that variation[4]. While systematic reviews are quite popular within the medical research field, they have not been applied regularly in ecology, but recognition of their application to ecological questions is growing[5]. In our case of achieving a better understanding of the drivers of ecological impacts of sea otter, a systematic literature review is an ideal tool to assess variable effects. This review will be the focus of my second thesis chapter.

In conducting my review, there will be three distinct phases: (1) review design and study collection, (2) meta-analysis, and (3) factor testing. In the first phase (review design and study collection), I will search the existing literature to collect studies that explicitly compare the availability of key ecosystem components (i.e. prey species, non-prey species, and macroalgae species) when sea otters are absent and present in the environment. By only including studies that make this comparison, I will define effects as the proportional change in each species’ or organism group’s availability (e.g. abundance, biomass, density, etc.) with and without sea otters. In determining these effects, it’s important to recognize that sea otters alter ecosystems via both direct and indirect pathways. Direct effects can be thought of as any change to prey availability via sea otter predation directly, while indirect effects can be thought of an any alteration to the broader ecosystem (i.e. non-prey species, macroalgae, habitat features) as an indirect result from sea otter predation on prey species. I will record both types of effects.

General schematic of a meta-analysis in a systematic review. A meta-analysis is the process of taking multiple datasets (i.e. Data 1, Data 2 etc.) from literature sources, calculating summary statistics or effects (i.e. Summary 1, Summary 2, etc.) for each dataset, running statistical procedures (e.g. SMA = sequential meta-analysis) to relate summary effects and investigate between study variation, and identifying important features driving variation. Source: MediCeption.

In phase two, I will use meta-analytical procedures (i.e. statistical analyses specific to systematic reviews) to calculate one standardized metric to represent sea otter effects. These effects will be calculated and averaged across all collected studies. As previously discussed, there may be key factors – such as sea otter density – that influence these effects. Therefore, in phase three (factor testing), effects will also be calculated separately for each a priori factor to test their influence on the effects. Such factors may include habitat type (i.e. hard or soft sediment), prey species (i.e. sea urchins, crabs, clams, etc.), otter density, depth, or time after otter recolonization.

In statistical terms, the goal of testing factors is to see if the variation between studies is impacted by calculating sea otter effects separately for each factor versus across all studies. In other words, if we find high variation in effects between studies, there may be important factors driving that variation. Therefore, in systematic reviews, we recalculate effects separately for each factor to try to explain that variation. If, however, after testing these factors, variation remains high, there may be other factors that we didn’t test that could be driving that remaining variation. Yet, without a priori knowledge on what those factors could be, such variation should be reported as a major source of uncertainty.

Predicting or anticipating the effects of reintroduced species is no easy feat. In instances where the ecological role of a species is well known – and there is adequate data – researchers can develop and use ecosystem models to predict with some certainty what these effects may be. Yet, in other cases where the species’ role is less studied, has less data, or is more variable, researchers must look to other tools – such as systematic reviews – to gain a better understanding of these potential effects. In this case, a systematic review on sea otter effects may prove particularly useful in helping managers understand what types of ecological effects of sea otters in Oregon are most likely, what the important factors are, and, after such review, what we still don’t know about these effects.

References:

[1] Seddon, P. J., Armstrong, D. P., and R. F. Maloney. 2007. Developing the science of reintroduction biology. Conservation Biology. 21(2): 303-312.

[2] Estes, J. A., Tinker, M. T., and J. L. Bodkin. 2009. Using ecological function to develop recovery criteria for depleted species: sea otters and kelp forests in the Aleutian Archipelago. Conservation Biology. 24(3): 852-860.

[3] Sutton, A. J., and J. P. T. Higgins. 2008. Recent developments in meta-analysis. Statistics in Medicine. 27: 625-650.

[4] Arnqvist, G., and D. Wooster. 1995. Meta-analysis: synthesizing research findings in ecology and evolution. TREE. 10(6): 236-240.

[5] Vetter, D., Rucker, G., and I. Storch. 2013. Meta-analysis: a need for well-defined usage in ecology and conservation biology. Ecosphere. 4(6): 1-13.

Inter- and Transdisciplinary Sea Otter Research

By Dominique Kone, Masters Student, Marine Resource Management

As the human population continues to grow, so does our impact on marine environments. In many cases, these problems – such as microplastics, vessel noise, or depleted fisheries – are far too grand for any one person to tackle on their own and it takes a team effort to find adequate solutions. Experts within a single field (e.g. ecology, economics, genetics) have been collaborating to tackle these issues for decades, but there is an increasing interest and recognition of the importance in working with others outside one’s own discipline.

It’s not surprising that most collaborative efforts are between experts from the same field. It’s easier to converse with those with similar vocabulary, we often enjoy learning from our peers, and our thought-processes and problem-solving skills are typically very similar. However, as issues become more complex and stretch across disciplines, the need for interdisciplinary collaboration becomes more and more imperative. As a graduate student studying marine resource management, I’ve learned the great value in conducting interdisciplinary work. Yet, I still have much to learn if I want to continue to help find solutions to the many complex marine issues. Therefore, over the next year, I’ve committed to joining a interdisciplinary team of graduate students, as part of an NSF-funded fellowship program at Oregon State University (OSU), to further investigate a potential sea otter reintroduction to Oregon. Here, I provide a brief overview of the program and my team’s goals for the coming year.

The fellowship program emphasizes both interdisciplinary and transdisciplinary approaches, so before I explain the program, it’s important to first understand these terms. In short, interdisciplinarity typically relates to experts from different fields analyzing, synthesizing, and coordinating their work as a whole (Choi & Pak 2006). Another way to think about this, in more practical terms, is if two or more experts share information and learn from one another; each expert can then individually apply that information or lessons-learned to their own line of work. In contrast, transdisciplinary work is slightly more collaborative, where experts work more hand-in-hand to develop a product or solution that transcends their disciplines’ traditional boundaries. The experts essentially create a product that would not have been possible working in isolation. In practice, the product(s) that stems from inter- and transdisciplinary work – if they truly are inter- or transdisciplinary by definition – is potentially very different.

With an increasing interest in interdisciplinary work, the National Science Foundation (NSF) developed the National Research Traineeship (NRT) program to encourage select universities to develop and implement innovative and transformative models for training graduate students in STEM disciplines. After soliciting proposals, the NSF awarded OSU one of these NRT projects to support OSU’s Risk and Uncertainty Quantification in Marine Science NRT Program. OSU’s NRT program was born out of the recognition that much of the complexity of marine issues is largely due to the uncertainty of natural and human systems. Therefore, the primary purpose of this program is to train the next generation of natural resource scientists and managers to be better equipped to study and manage complex marine systems, especially under extreme uncertainty and potential risk.

This NRT program trains graduate students in three core concept areas: coupled natural human systems, big data, and risk and uncertainty analyses and communications. To learn these core concepts, students fulfil a minor that includes coursework in statistical inference, uncertainty quantification, risk analyses, earth system science, and social systems. In addition to the minor, students also conduct collaborative research in small (3-5 students) cross-disciplinary teams to address specific issues in marine resource management. Within each team, students come from different disciplines and fields, and must learn to work together to produce a transdisciplinary research product. Throughout the year, each team will develop a set of research questions to address their issue at hand, conduct research which links all their fields, and produce a transdisciplinary report summarizing the process they undertook and the end product. Most students who are accepted into the NRT program are awarded one-year fellowships, funded by the NSF.

At the start of this academic year, I was awarded one of these NRT fellowships to address the many issues and implications of a potential sea otter reintroduction to Oregon. Over the next year, I will be working with two other OSU graduate students with backgrounds in genetics and social sciences. Our task is to not only investigate the ecological implications – which I am currently doing for my own thesis – but we are to expand this investigation to also address many of the genetic, political, and social factors, as well. While each of us is capable of addressing one of these factors individually, the real test will be in finding linkages between each of our disciplines to make this project truly transdisciplinary.

Structure and vision of OSU’s NRT program. Source: Oregon State University.

Since our project started, we have worked to better understand each another’s expertise, interests, and the general need for a transdisciplinary project of this sort. After acquiring this base understanding, we spent a considerable amount of time developing research questions and potential methods for addressing our issue. Throughout this process, it’s already become apparent that each of us is starting to learn important teamwork and collaboration skills, including effective communication and explanation of complicated concepts, active listening, critical thinking, and constructive feedback. While these skills are imperative for our research over the next year, they are also life-long skills that we’ll continue to use in our careers beyond graduate school.

As I’ve stated previously, learning to be an effective collaborator is extremely important to me. Getting the opportunity to work interdisciplinarily is what attracted me to my thesis, the marine resource management program, and the NRT program. By choosing to take my graduate education down this path, I’ve been fortunate to obtain important skills in collaboration, as well as work on a project that allows me to tackle real-world issues and creatively develop scientifically-based solutions. I have high hopes for this NRT project, and I’m excited to continue to conduct meaningful and targeted research over the next year with my new team.

2018-19 OSU NRT Cohort. Source: Oregon State University.

References:

Choi, B. C., and A. W. Pak. Multidisciplinarity, interdisciplinarity and transdisciplinarity in health research, service, education and policy: 1. Definitions, objectives, and evidence of effectiveness. Clinical and Investigative Medicine. 29(6): 351-64.

Oregon Sea Otter Status of Knowledge Symposium

By Dominique Kone, Masters Student in Marine Resource Management

Over the past year, the GEMM Lab has been investigating the ecological factors associated with a potential sea otter reintroduction to Oregon. A potential reintroduction is not only of great interest to our lab, but also to several other researchers, managers, tribes, and organizations in the state. With growing interest, this idea is really starting to gain momentum. However, the best path forward to making this idea a reality is somewhat unknown, and will no doubt take a lot of time and effort from multiple groups.

In an effort to catalyze this process, the Elakha Alliance – led by Bob Bailey – organized the Oregon Sea Otter Status of Knowledge Symposium earlier this month in Newport, OR. The purpose of this symposium was to share information, research, and lessons learned about sea otters in other regions. Speakers – primarily scientists, managers, and graduate students – flew in from all over the U.S. and the Canadian west coast to share their expertise and discuss various factors that must be considered before any reintroduction efforts begin. Here, I review some of the key takeaways from those discussions.

To start the meeting, Dr. Anne Salomon – an associate professor from Simon Fraser University – and Kii’iljuus Barbara Wilson – a Haida Elder – gave an overview of the role of sea otters in nearshore ecosystems and their significance to First Nations in British Columbia. Hearing these perspectives not only demonstrated the various ecological effects – both direct and indirect – of sea otters, but it also illustrated their cultural connection to indigenous people and the role tribes can play (and currently do play in British Columbia) in co-managing sea otters. In Oregon, we need to be aware of all the possible effects sea otters may have on our ecosystems and acknowledge the opportunity we have to restore these cultural connections to Oregon’s indigenous people, such as the Confederated Tribes of Siletz Indians.

Source: The Elakha Alliance and the Confederated Tribes of Siletz Indians.

The symposium also involved several talks on the recovery of sea otter populations in other regions, as well as current limitations to their population growth. Dr. Lilian Carswell and Dr. Deanna Lynch – sea otter and marine conservation coordinators with the U.S. Fish & Wildlife Service – and Dr. Jim Bodkin – a sea otter ecologist – provided these perspectives. Interestingly, not all stocks are recovering at the same rate and each population faces slightly different threats. In California, otter recovery is slowed by lack of available food and mortality due to investigative shark bites, which prevents range expansion. In other regions, such as Washington, the population appears to be growing rapidly and lack of prey and shark bite-related mortality appear to be less important. However, this population does suffer from parasitic-related mortality. The major takeaway from these recovery talks is that threats can be localized and site-specific. In considering a reintroduction to Oregon, it may be prudent to investigate if any of these threats and population growth limitations exist along our coastline as they could decrease the potential for sea otters to reestablish.

Source: The Seattle Aquarium and U.S. Fish & Wildlife Service.

Dr. Shawn Larson – a geneticist and ecologist from the Seattle Aquarium – gave a great overview of the genetic research that has been conducted for historical (pre-fur trade) Oregon sea otter populations. She explained that historical Oregon populations were genetically-similar to both southern and northern populations, but there appeared to be a “genetic gradient” where sea otters near the northern Oregon coast were more similar to northern populations – ranging to Alaska – and otters from the southern Oregon coast were more similar to southern populations – ranging to California. Given this historic genetic gradient, reintroducing a mixture of sea otters – subsets from contemporary northern and southern stocks – should be considered in a future Oregon reintroduction effort. Source-mixing could increase genetic diversity and may more-closely resemble genetic diversity levels found in the original Oregon population.

At the end of the meeting, an expert panel – including Dr. Larson, Dr. Bodkins, Dr. Lynch, and Dr. Carswell – provided their recommendations on ways to better inform this process. To keep this brief, I’ll discuss the top three recommendations I found most intriguing and important.

Gain a better understanding of sea otter social behavior. Sea otters have strong social bonds, and previous reintroductions have failed because relocated individuals returned to their capture sites to rejoin their source populations. While this site fidelity behavior is relatively understood, we know less about the driving mechanisms – such as age or sex – of those behaviors. Having a sound understanding of these behaviors and their mechanisms could help to identify those which may hinder reestablishment following a reintroduction.
When anticipating the impacts of sea otters on ecosystems, investigate the benefits too. When we think of impacts, we typically think of costs. However, there are documented benefits of sea otters, such as increasing species diversity (Estes & Duggins 1995, Lee et al. 2016). Identifying these benefits – as well as to people – would more completely demonstrate their importance.
Investigate the human social factors and culture in Oregon relative to sea otters, such as perceptions of marine predators. Having a clear understanding of people’s attitudes toward marine predators – particularly marine mammals – could help managers better anticipate and mitigate potential conflicts and foster co-existence between otters and people.

While much of the symposium was focused on learning from experts in other regions, I would be remiss if I didn’t recognize the great talks given by a few researchers in Oregon – including Sara Hamilton (OSU doctoral student), Dr. Roberta Hall (OSU emeritus professor), Hannah Wellman (University of Oregon doctoral student), and myself. Individually, we spoke about the work that has already been done and is currently being done on this issue – including understanding bull kelp ecology, studying sea otter archaeological artifacts, and a synthesis of the first Oregon translocation attempt. Collectively, our talks provided some important context for everyone else in the room and demonstrated that we are working to make this process as informed as possible for managers. Oregon has yet to determine if they will move forward with a sea otter reintroduction and what that path forward will look like. However, given this early interest – as demonstrated by the symposium – we, as researchers, have a great opportunity to help guide this process and provide informative science.

References:

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: 75-100.

Lee, L. C., Watson, J. C., Trebilco, R., and A. K. Salomon. 2016. Indirect effects and prey behavior mediate interactions between an endangered prey and recovering predator. Ecosphere. 7(12).

Cloudy with a chance of blue whales

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

References:

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

“Applied conservation science”

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

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

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

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

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

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

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

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

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

Oregon sea otter reintroduction: opinions, perspectives, and theories

By Dominique Kone, Masters Student in Marine Resource Management

Species reintroductions can be hotly contested issues because they can negatively impact other species, ecosystems, and society, as well as failing, altogether. The uncertainty of their outcomes forces stakeholder groups to form their own opinions on whether it’s a good idea to proceed with a reintroduction. When you have several groups with conflicting values and views, managers need to focus on the information most important for them to make a well-informed decision on whether to pursue a reintroduction.

As researchers, we can play an important role by carefully considering and addressing these views through our research, if the appropriate data is available. Despite being in the early days of our study on the potential sea otter reintroduction to Oregon, we have already heard several perspectives regarding its potential success, the type of research we should do, and if sea otters should be brought back to Oregon. Here, I present some of the most interesting and relevant opinions, perspectives, and theories I’ve heard regarding this reintroduction idea.

The first reintroduction failed because of X, Y, and Z.

From 1970-1971, managers translocated 93 sea otters to Oregon in a reintroduction effort (Jameson et al. 1982). However, in a matter of 5-6 years, all sea otters disappeared, and the effort was considered a failure. Researchers have theorized that sea otters left Oregon due to a lack of suitable habitat and prey, or to return home to sites from which they were captured. Others have reasoned that managers should have introduced southern sea otters instead of northern sea otters, suggesting one subspecies’ genetic pre-disposition may improve their chance for survival.

Knowing the reasons for this failure may help managers avoid these causes in a future reintroduction attempt and increase its chance of success. We, as scientists, can also gain insight from knowing these causes because this may help us better tailor our research to potentially investigate whether those causes still pose a threat to sea otters during a second attempt. Unfortunately, we lack concrete evidence on what exactly caused this failure, but we can still work to test some these theories.

An otter is an otter, no matter where you put it.

There is evidence that northern and southern sea otters are genetically distinct, to a certain degree (Valentine et al. 2008, Larson et al. 2012), and hypotheses have been put forward that the two subspecies may be behaviorally- and ecologically-distinct, too. Studies have shown that northern and southern sea otters have different sized and shaped skulls and teeth, which researchers hypothesize may be a specialized foraging adaptation for consuming different prey species (Campbell & Santana 2017, Timm-Davis et al. 2015). This view suggests that each subspecies has developed unique traits to adapt to the environmental conditions specific to their current ranges. Therefore, when considering which subspecies to bring to Oregon, managers should reintroduce the subspecies with traits better-suited to cope with the types of habitat, prey assemblages, and oceanographic conditions specific to Oregon.

However, other scientists hold the opposite view, and argue that “an otter is an otter” no matter where you put it. This perspective suggests that both subspecies have an equal chance at surviving in any type of suitable habitat because all otters behave in similar ways. Therefore, ecologically, it may not matter which subspecies managers bring to Oregon.

Oregon doesn’t have enough sea otter habitat.

Kelp is considered important sea otter habitat. In areas with high sea otter densities, such as central and southern California, kelp forests are persistent throughout the year. However, in Oregon, our kelp primarily consists of bull kelp – a slightly more fragile species compared to the durable giant kelp in California. In winter, this bull kelp gets dislodged during intense storms, resulting in seasonal changes in kelp availability. Managers worry that this seasonality could reduce the amount of suitable habitat, to the point where Oregon may not be able to support sea otters.

Yet, we know sea otters used to exist here; therefore, we can assume there must have been some suitable habitat that may persist today. Furthermore, sea otters use a range of habitats, including estuaries, bays, and reefs (Laidre et al. 2009, Lafferty & Tinker 2014, Kvitek et al. 1988). Therefore, even during times when kelp is less abundant, sea otters could use these other forms of habitat along the Oregon coast. Luckily, we have the spatial tools and data to assess how much, where, and when we have suitable habitat, and I will specifically address this in my thesis.

They’ll eat everything!

Sea otters are famous for their voracious appetites for benthic invertebrates, some of which are of commercial and recreational importance to nearshore fisheries. In some cases, sea otters have significantly reduced prey densities, such as sea urchins and Dungeness crab (Garshelis & Garshelis 1984, Estes & Palmisano 1974). However, without a formal analysis, it’s difficult to know if sea otters will have similar impacts on Oregon’s nearshore species, as well as at spatial scale these impacts will occur and whether our fisheries will be affected. We can predict where sea otters are likely to occur based on the presence of suitable habitat, but foraging impacts could be more localized or widespread across sea otter’s entire potential range. To better anticipate these impacts, managers will need an understanding of how much sea otters eat, where foraging could occur based on the availability of prey, and where sea otters and fisheries are likely to interact. I will also address this concern in my thesis.

To reintroduce or not to reintroduce? That is the question.

I have found that many scientists and managers have strong opinions on whether it’s appropriate to bring sea otters back to Oregon. Those who argue against a reintroduction often highlight many of the theories already mentioned here – lack of habitat, potential impacts to fisheries, and genetics. While other opponents provided more logistical and practical justifications, such as confounding politics, as well as difficulties in getting public support and regulatory permission to move a federally-listed species.

In contrast, proponents of this idea argue that a reintroduction could augment the recovery of the species by providing additional habitat for the species to rebound to pre-exploitation levels, as well as allowing for increased gene flow between southern and northern sea otter populations. Other proponents have brought up potential benefits to humans, such restoring ecosystem services, providing an economic boost through tourism, or preserving tribal and cultural connections. Such benefits may be worth attempting another reintroduction effort.

As you can see, there are several opinions and perspectives related to a potential sea otter reintroduction to Oregon. While it’s important to consider all opinions, managers still need facts to make key decisions. Scientists can play an important role in providing this information, so managers can make a well-informed decision. Oregon managers have not yet decided whether to proceed with a sea otter reintroduction, but our lab is working to provide them with reliable and accurate science, so they may form their own opinions and arrive at their own decision.

References:

Estes, J. A. and J. F. Palmisano. 1974. Sea otters: the role in structuring nearshore communities. Science. 185: 1058-1060.

Garshelis, D. L. and J. A. Garshelis. 1984. Movements and management of sea otters in Alaska. The Journal of Wildlife Management. 48: 665-678.

Jameson, R. J, Kenyon, K. W., Johnson, A. M., and H. M. Wight. 1982. History and status of translocated sea otter populations in North America. Wildlife Society Bulletin. 10: 100-107.

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

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