Who Am I? Exploring the theory of individualisation among marine mammals

By Lisa Hildebrand, MSc student, OSU Department of Fisheries and Wildlife, Geospatial Ecology of Marine Megafauna Lab

“Just be yourself!” is a phrase that everyone has probably heard at least once in their lives. The idea of being an individual who is distinctly different from other individuals is a concept that is focal to the society we live in today. While historically it may have been frowned upon to be the “black sheep in the crowd”, nowadays that seems to be the goal.

Source: Go Comics.

This quest for uniqueness has resulted in different styles of fashion, speech, profession, interest in art, music, literature, automobile types – the list is endless. The American Psychological Association defines personality as the “individual differences in characteristic patterns of thinking, feeling and behaving”1. So, all of the choices we make on a daily basis shape our behaviour, and our behaviour in turn shapes our personality.

Since personality is something that is so engrained within human society, it isn’t surprising that ecologists have explored this concept among non-humans. Decades of research have resulted in an abundance of literature detailing personality in many different taxa and species, ranging from chimpanzees to mice to ants2. Naturally, the definition of personality for animals differs from that for humans since the assessment of animal thoughts and feelings is still somewhat of a locked box to us. Nevertheless, the behavioural aspect of the two definitions remains consistent whereby animal personality is broadly defined as “consistent variation in behavioural traits between individuals”3.

Although I am an early career marine mammal ecologist finding my footing in this rapidly expanding field, I have a keen interest in teasing apart possible cases of individual specialisation within marine mammal populations. So, before getting straight into the nitty gritty of individual specialisation, it is important for me to take a small step back and consider the concept of specialisation as applied to small subgroups or populations of marine mammals.

Specialisations are mostly related to foraging or feeding behaviour whereby a subgroup of individuals will develop a novel method to locate and capture prey. These behaviours have been reported for several marine mammal species, and are strongly coupled to intra and inter-specific competition with other predators for prey and habitat characteristics. Furthermore, it is posited that factors such as resource benefits (e.g. energy content of prey), prey escape rates, and handling times can be minimised if specialisation for a particular prey type or habitat occurs4.

In Florida Bay, Torres & Readdocumented two distinct foraging strategies employed by two bottlenose dolphin ecotypes. One dolphin ecotype was found to forage using deep diving with erratic surfacings, whereas the second ecotype chose to forage through mud ring feeding and were mostly seen in shallow habitats. The latter ecotype is in fact so adapted to shallow depths that dolphins were typically observed foraging in waters <2 m deep. In this example, the foraging tactics of the two ecotypes are strongly driven by habitat conditions, specifically depth. The video below is aerial footage of bottlenose dolphins performing mud ring feeding.

Such group specialisations have been identified not only in several other bottlenose dolphin populations around the world6,7, but also in other cetacean species, including killer whales (distinct differences in target prey between transients and residents8), Guiana dolphins (mud-plume feeding9), humpback dolphins (strand feeding10), and several others. Noticeable here is that these records concern Odontocete species, which is not surprising since these toothed whales are vastly different to baleen whales in that they often live in structured groups with bonds between individuals sometimes lasting for decades11. Long-term relationships are conducive to developing specialised group hunting strategies as individuals will spend considerable time with one another and the success of obtaining prey depends on the cooperation and coordination of the group.

For baleen whales and other marine mammals, such as pinnipeds, where life history and social organisation is more geared toward a solitary life, examples of group specialisations are relatively rare (with the exception of the well-documented bubble-net feeding exhibited by humpback whales12). While group specialisation may not be as prevalent in Mysticetes, the same problems of inter and intra-specific competition persists among these more solitary species too, which would suggest that individuals should develop their own unique foraging tactics and preferences. Evidence for individualisation is hard to obtain since it requires repeated observations of the same individuals over time with good knowledge of the prey type being consumed and/or the habitat being used to forage in.

Nevertheless, examples do exist. Perhaps the most well-documented case of individualisation within a population for marine mammals is of the sea otter. Estes et al. (2003) describe 10 female sea otters in Monterey Bay that had high inter-individual variation in diet, which they investigated over a scale of 8 years13. Most females specialised on 1-4 types of prey, with marked differences between the diets chosen by each female, despite habitat overlap. This individualisation of diet was not attributable to variation in prey availability; hence, authors concluded that this extreme specialisation occurred to reduce intra-population competition for prey.

Ecologists have historically (and probably still to this day) disagreed on whether individualisation actually matters in the grand scheme of things. There are generally three schools of thought on the matter: (1) individual specialisation is rare and/or weakly influences population dynamics and so is not very important; (2) while individual specialisation does occur and may in fact be commonplace, it does not affect ecological processes at the large population scale; and (3) individual specialisation is widespread and can significantly impact population dynamics and/or ecosystem function.

As you might have guessed by this point, I find myself in the third school of thought. There are many arguments supporting this theory, and what I believe to be very good arguments against statements 1 and 2. While I have only provided one specific named example for individual specialisation in a marine mammal, there are several documented cases of such occurrences among other marine taxa (e.g., pinnipeds14, sharks15, fish16) and a much larger number of studies for terrestrial species4. Thus, the claim that it is rare or weak, seems implausible to me.

Statement 2 is a little more complicated to tackle as it involves understanding how actions on a relatively small scale affect a whole population or even an ecosystem. For instance, consider two female sea otters living in a small coastal area where one sea otter prefers to eat turban snails and the other exclusively feeds on abalone. The sudden decline in abundance of either of these prey could lead to serious health and reproductive issues for those females. Should the low prey abundance persist, then poor health and reproduction of several females in a population that specialise on that prey item can rapidly lead to genetic loss and an overall population decline. Particularly if an individual’s or species’ home range is rather restricted or small. In the case of the sea otter, which are often touted as a keystone species due to its presence preventing sea urchin barren formation that is known to wreak havoc on kelp forests, knock-on effects of such a population decline could result in poor overall ecosystem health.

It may be easy to assume that one individual dolphin, otter, seal or whale cannot possibly make a difference to a whole population or ecosystem. This assumption strikes me as a little odd since humans are always told to ‘be the change they wish to see in the world’ and that ‘every person can make a difference’. Why then should these sentiments not be applicable to non-humans? While a gray whale may not hold a sign at a protest or run for president (actions commonly considered to cause change in the human world), perhaps the choice that a gray whale makes every day to only consume one species of zooplankton, can influence other gray whales in the area, predators from other taxa, habitat structure, other prey availability, and/or cause trophic cascades.

Through my research, I aim to elucidate whether the gray whales display some level of foraging individualisation while feeding in Port Orford, Oregon. I will use data from four years to compare tracks of individual whales with zooplankton samples collected in the area to correlate each individual’s movement patterns with prey availability. I will assess the quality of prey through bomb calorimetry and microplastic analysis of the zooplankton samples to determine energetic content and pollutant levels, respectively. This prey assessment will describe the potential effects of prey specialization on whales, which is fundamental to assessing overall population health. Individualisation can strongly affect fitness of individuals, either positively or negatively depending on several factors, which will undoubtedly have an impact at the population level.

(The videos below are examples of two different tactics we see the gray whales display while foraging along the Oregon coast in the summer months. The first video shows a whale foraging among kelp with some very acrobatic moves, while the second is of a whale employing the ‘sharking’ method where the whale is feeding benthically in such shallow depths that both the pectoral fin and the fluke stick out of the water, making the whale look like a ‘shark’.)

References

  1. American Psychological Association, Personality. Retrieved from: https://www.apa.org/topics/personality/.
  2. Carere C., & Locurto, C., Interaction between animal personality and animal cognition. Current Zoology, 2015. 57(4): 491-498.
  3. Gosling, S.D., From mice to men: what can we learn about personality from animal research?Psychological Bulletin, 2001. 127(1): 45-86.
  4. Bolnick, D.I., et al., The ecology of individuals: incidence and implications of individual specialisation. The American Naturalist, 2003. 161(1): 1-28.
  5. Torres, L.G., & Read, A. J., Where to catch a fish? The influence of foraging tactics on the ecology of bottlenose dolphins (Tursiops truncatus) in Florida Bay, Florida. Marine Mammal Science, 2009. 25(4): 797-815.
  6. Gisburne, T.J., & Connor, R.C., Group size and feeding success in strand-feeding bottlenose dolphins (Tursiops truncatus) in Bull Creek, South Carolina. Marine Mammal Science, 2015. 31(3): 1252-1257.
  7. Gazda, S.K., et al., A division of labour with role specialization in group-hunting bottlenose dolphins (Tursiops truncatus) off Cedar Keys, Florida.Proceedings of the Royal Society: Biological Sciences, 2005. 272(1559): 135-140.
  8. Ford, J.K.B., et al., Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters. Canadian Journal of Zoology, 1998. 76(8): 1456-1471.
  9. Rossi-Santos, M.R., & Wedekin, L.L., Evidence of bottom contact behaviour by estuarine dolphins (Sotalia guianensis) on the Eastern Coast of Brazil.Aquatic Mammals, 2006. 32(2): 140-144.
  10. Peddemors, V.M., & Thompson, G., Beaching behaviour during shallow water feeding by humpback dolphins (Sousa plumbea). Aquatic Mammals, 1994. 20(2): 65-67.
  11. Tyack, P., Population biology, social behavior and communication in whales and dolphins. Trends in Ecology & Evolution, 1986. 1(6): 144-150.
  12. Wiley, D., et al., Underwater components of humpback whale bubble-net feeding behaviour.Behaviour, 2011. 148(5/6): 575-602.
  13. Estes, J.A., et al., Individual variation in prey selection by sea otters: patterns, causes and implications. Journal of Animal Ecology, 2003. 72(1): 144-155.
  14. Cherel, Y., et al., Stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the Southern Ocean. Journal of Animal Ecology, 2007. 76(4): 826-836.
  15. Matich, P., et al., Contrasting patterns of individual specialization and trophic coupling in two marine apex predators. Journal of Animal Ecology, 2010. 80(1): 294-305.
  16. Svanbäck, R., & Persson, L., Individual diet specialization, niche width and population dynamics: implications for trophic polymorphisms. Journal of Animal Ecology, 2004. 73(5): 973-982.

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.

Source: The Elakha Alliance

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.

  1. 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.
  2. 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.
  3. 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.
Source: Paul Malcolm

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).

The Recipe for a “Perfect” Marine Mammal and Seabird Cruise

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

Science—and fieldwork in particular—is known for its failures. There are websites, blogs, and Twitter pages dedicated to them. This is why, when things go according to plan, I rejoice. When they go even better than expected, I practically tear up from amazement. There is no perfect recipe for a great marine mammal and seabird research cruise, but I would suggest that one would look like this:

 A Great Marine Mammal and Seabird Research Cruise Recipe:

  • A heavy pour of fantastic weather
    • Light on the wind and seas
    • Light on the glare
  • Equal parts amazing crew and good communication
  • A splash of positivity
  • A dash of luck
  • A pinch of delicious food
  • Heaps of marine mammal and seabird sightings
  • Heat to approximately 55-80 degrees F and transit for 10 days along transects at 10-12 knots
The end of another beautiful day at sea on the R/V Shimada. Image source: Alexa K.

The Northern California Current Ecosystem (NCCE) is a highly productive area that is home to a wide variety of cetacean species. Many cetaceans are indicator species of ecosystem health as they consume large quantities of prey from different levels in trophic webs and inhabit diverse areas—from deep-diving beaked whales to gray whales traveling thousands of miles along the eastern north Pacific Ocean. Because cetacean surveys are a predominant survey method in large bodies of water, they can be extremely costly. One alternative to dedicated cetacean surveys is using other research vessels as research platforms and effort becomes transect-based and opportunistic—with less flexibility to deviate from predetermined transects. This decreases expenses, creates collaborative research opportunities, and reduces interference in animal behavior as they are never pursued. Observing animals from large, motorized, research vessels (>100ft) at a steady, significant speed (>10kts/hour), provides a baseline for future, joint research efforts. The NCCE is regularly surveyed by government agencies and institutions on transects that have been repeated nearly every season for decades. This historical data provides critical context for environmental and oceanographic dynamics that impact large ecosystems with commercial and recreational implications.

My research cruise took place aboard the 208.5-foot R/V Bell M. Shimada in the first two weeks of May. The cruise was designated for monitoring the NCCE with the additional position of a marine mammal observer. The established guidelines did not allow for deviation from the predetermined transects. Therefore, mammals were surveyed along preset transects. The ship left port in San Francisco, CA and traveled as far north as Cape Meares, OR. The transects ranged from one nautical mile from shore and two hundred miles offshore. Observations occurred during “on effort” which was defined as when the ship was in transit and moving at a speed above 8 knots per hour dependent upon sea state and visibility. All observations took place on the flybridge during conducive weather conditions and in the bridge (one deck below the flybridge) when excessive precipitation was present. The starboard forward quarter: zero to ninety degrees was surveyed—based on the ship’s direction (with the bow at zero degrees). Both naked eye and 7×50 binoculars were used with at least 30 percent of time binoculars in use. To decrease observer fatigue, which could result in fewer detected sightings, the observer (me) rotated on a 40 minutes “on effort”, 20 minutes “off effort” cycle during long transits (>90 minutes).

Alexa on-effort using binoculars to estimate the distance and bearing of a marine mammal sighted off the starboard bow. Image source: Alexa K.

Data was collected using modifications to the SEEbird Wincruz computer program on a ruggedized laptop and a GPS unit was attached. At the beginning of each day and upon changes in conditions, the ship’s heading, weather conditions, visibility, cloud cover, swell height, swell direction, and Beaufort sea state (BSS) were recorded. Once the BSS or visibility was worse than a “5” (1 is “perfect” and 5 is “very poor”) observations ceased until there was improvement in weather. When a marine mammal was sighted the latitude and longitude were recorded with the exact time stamp. Then, I noted how the animal was sighted—either with binoculars or naked eye—and what action was originally noticed—blow, splash, bird, etc. The bearing and distance were noted using binoculars. The animal was given three generalized behavior categories: traveling, feeding, or milling. A sighting was defined as any marine mammal or group of animals. Therefore, a single sighting would have the species and the best, high, and low estimates for group size.

By my definitions, I had the research cruise of my dreams. There were moments when I imagined people joining this trip as a vacation. I *almost* felt guilty. Then, I remember that after watching water for almost 14 hours (thanks to the amazing weather conditions), I worked on data and reports and class work until midnight. That’s the part that no one talks about: the data. Fieldwork is about collecting data. It’s both what I live for and what makes me nervous. The amount of time, effort, and money that is poured into fieldwork is enormous. The acquisition of the data is not as simple as it seems. When I briefly described my position on this research cruise to friends, they interpret it to be something akin to whale-watching. To some extent, this is true. But largely, it’s grueling hours that leave you fatigued. The differences between fieldwork and what I’ll refer to as “everything else” AKA data analysis, proposal writing, manuscript writing, literature reviewing, lab work, and classwork, are the unbroken smile, the vaguely tanned skin, the hours of laughter, the sea spray, and the magical moments that reassure me that I’ve chosen the correct career path.

Alexa photographing a gray whale at sunset near Newport, OR. Image source: Alexa K.

This cruise was the second leg of the Northern California Current Ecosystem (NCCE) survey, I was the sole Marine Mammal and Seabird Observer—a coveted position. Every morning, I would wake up at 0530hrs, grab some breakfast, and climb to the highest deck: the fly-bridge. Akin to being on the top of the world, the fly-bridge has the best views for the widest span. From 0600hrs to 2000hrs I sat, stood, or danced in a one-meter by one-meter corner of the fly-bridge and surveyed. This visual is why people think I’m whale watching. In reality, I am constantly busy. Nonetheless, I had weather and seas that scientists dream about—and for 10 days! To contrast my luck, you can read Florence’s blog about her cruise. On these same transects, in February, Florence experienced 20-foot seas with heavy rain with very few marine mammal sightings—and of those, the only cetaceans she observed were gray whales close to shore. That starkly contrasts my 10 cetacean species with upwards of 45 sightings and my 20-minute hammock power naps on the fly-bridge under the warm sun.

Pacific white-sided dolphins traveling nearby. Image source: Alexa K.

Marine mammal sightings from this cruise included 10 cetacean species: Pacific white-sided dolphin, Dall’s porpoise, unidentified beaked whale, Cuvier’s beaked whale, gray whale, Minke whale, fin whale, Northern right whale dolphin, blue whale, humpback whale, and transient killer whale and one pinniped species: northern fur seal. What better way to illustrate these sightings than with a map? We are a geospatial lab after all.

Cetacean Sightings on the NCCE Cruise in May 2018. Image source: Alexa K.

This map is the result of data collection. However, it does not capture everything that was observed: sea state, weather, ocean conditions, bathymetry, nutrient levels, etc. There are many variables that can be added to maps–like this one (thanks to my GIS classes I can start adding layers!)–that can provide a better understanding of the ecosystem, predator-prey dynamics, animal behavior, and population health.

The catch from a bottom trawl at a station with some fish and a lot of pyrosomes (pink tube-like creatures). Image source: Alexa K.

Being a Ph.D. student can be physically and mentally demanding. So, when I was offered the opportunity to hone my data collection skills, I leapt for it. I’m happiest in the field: the wind in my face, the sunshine on my back, surrounded by cetaceans, and filled with the knowledge that I’m following my passion—and that this data is contributing to the greater scientific community.

Humpback whale photographed traveling southbound. Image source: Alexa K.

Assessing suitable sea otter habitat along Oregon’s coast

By Dominique Kone, Masters Student in Marine Resource Management

When considering a species reintroduction into an area, it is important to assess the suitability of the area’s habitat before such efforts begin. By doing this assessment at the outset, managers and conservationists can gain a better understanding of the capacity of the area to support a viable population overtime, and ultimately the success of the reintroduction. However, to do a habitat assessment, researchers must first have a base understanding of the species’ ecological characteristics, behavior, and the physical habitat features necessary for the species’ survival. For my thesis, I plan to conduct a similar assessment to identify suitable sea otter habitat to inform a potential sea otter reintroduction to the Oregon coast.

Source: The Tribune.

To start my assessment, I conducted a literature review of studies that observed and recorded the various types of habitats where sea otters currently exist. In my research, I learned that sea otters use in a range of environments, each with a unique set of habitat characteristics. With so many features to sort through, I have focused on specific habitat features that are consistent across most of the current range of sea otters – from Alaska to California – and are important for at least some aspects of sea otters’ everyday life or behavior, specifically foraging. Focusing my analysis on foraging habitat makes sense as sea otters require around 30% of their body weight in food every day (Costa 1978, Reidman & Estes 1990). Meaning sea otters spend most of their day searching for food.

Here, I present four habitat features I will incorporate into my analysis and explain why these features are important for sea otter foraging behavior and survival.

Habitat Features:

  1. Kelp: Sea otters are famously known for the benefits they provide to kelp forests. In the classic three-trophic-level model, sea otters allow for the growth of kelp by keeping sea urchins – consumers of kelp – in check (Estes & Palmisano 1974). Additionally, sea otters and kelp have a mutually-beneficial relationship. Sea otters will often wrap themselves amongst the top of kelp stocks while feeding, resting, or grooming to prevent being carried away by surface currents. Meanwhile, it’s thought that kelp provide a refuge for sea otters seeking to avoid predators, such as sharks, as well as their prey.
Source: The Telegraph.
  1. Distance from Kelp: The use of kelp, by sea otters, is relatively straight-forward. Yet, kelp can still have an influence on sea otter behavior even when not used directly. A 2014 study found that sea otters along the southern California coast were almost 10 times more likely to be located within kelp habitat than outside, while outside kelp beds sea otter numbers declined with distance from the edge of kelp canopies. Sea otters will often forage outside or next to kelp canopies when prey’s available, and even sometimes to socialize in age- or sex-specific rafts (Lafferty & Tinker 2014). These findings indicate that sea otters can and do regularly disperse away from kelp habitat, but because they’re so dependent on kelp, they don’t stray very far.

 

  1. Seafloor Substrate: Sea otters forage over a variety of sediment substrates, including rocks, gravel, seagrass, and even sometimes sand. For example, sea otters hunt sea urchins over rocky substrates, while in other areas they may hunt for crabs in seagrass beds (Estes & Palmisano 1974, Hughes et al. 2014). The type of substrate sea otters forage in typically depends on the substrate needs of their target prey species. Despite some variability across their range, sea otters predominantly forage in rocky substrate environments. Rocky substrate is also necessary for kelp, whose holdfasts need to attach to hard, stable surfaces (Carney et al. 2005).
Source: Save our Seas Foundation.
  1. Depth: Seafloor depth plays a pivotal role in sea otter foraging behavior and therefore acts as a natural boundary that determines how far away from shore sea otters distribute. Many of the prey species sea otters eat – including sea urchins, crabs, and snails – live on the seafloor of the inner continental shelf, requiring sea otters to dive when foraging. Interestingly, sea otters exhibit a non-linear relationship with depth, where most individuals forage at intermediate depths as opposed to extremely shallow or deep waters. One study found the average foraging depth to be around 15 meters (Lafferty & Tinker 2014). This behavior results in a hump-shaped distribution of diving patterns as illustrated in Figure 1 below.
Figure 1. Average probability of occurrence as a function of depth for female (A) and male (B) sea otters as predicted by a synoptic model of space-use (Tinker et al. 2017).

Of course, local conditions and available habitat are always a factor. For example, a study found that sea otters along the coast of Washington foraged further from shore and in slightly shallower environments than sea otters in California (Laidre et al. 2009), indicating that local topography is important in determining distribution. Additionally, diving requires energy and limits how deep sea otters are able to forage for prey. Therefore, diving patterns are not only a function of local topography, but also availability of prey and foraging efficiency in exploiting that prey. Regardless, most sea otter populations follow this hump-shaped diving pattern.

Source: Doretta Smith.

These features are not a complete list of all habitat characteristics that support viable sea otter populations, but seem to be the most consistent throughout their entire range, as well as present in Oregon’s nearshore environment – making them ideal features to include in my analysis. Furthermore, other studies that have predicted suitable sea otter habitat (Tinker et al. 2017), estimated carrying capacity as a product of suitable habitat identification (Laidre et al. 2002), or simply observed sea otter foraging behavior (Estes & Palmisano 1974), have echoed the importance of these four habitat features to sea otter survival.

As with most reintroduction efforts, the process of identifying suitable habitat for the species of interest can be complicated. No two ecosystems or habitats are exactly alike and each comprise their own unique set of physical features and are impacted by environmental processes to varying degrees. The Oregon coast consists of a unique combination of oceanographic conditions and drivers that likely impact the degree and amount of available habitat to sea otters. Despite this, by focusing on the habitat features that are consistently preferred by sea otters across most of their range, I will be able to identify habitat most suitable for sea otter survival in Oregon. The questions of where this habitat is and how much is available are what I’ll determine soon, so stay tuned.

References:

Carney, L. T., Robert Waaland, J., Kilinger, T., and K. Ewing. 2005. Restoration of the bull kelp Nereocystis luetkeana in nearshore rocky habitats. Marine Ecology Progress Series. 302: 49-61.

Costas, D. P. 1978. The ecological energetics, waters, and electrolyte balance of the California sea otter (Enhydra lutris). Ph.D. dissertation, University of California, Santa Cruz.

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

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.

Lafferty, K. D. and M. T. Tinker. 2014. Sea otters are recolonizing southern California in fits and starts. Ecosphere. 5(5): 1-11.

Laidre et al. 2002. Estimates of carrying capacity for sea otters in Washington state. Wildlife Society Bulletin. 30(4): 1172-1181.

Laidre et al. 2009. Spatial habitat use patterns of sea otters in coastal Washington. Journal of Mammalogy. 90(4): 906-917.

Tinker et al. 2017. Southern sea otter range expansion and habitat use in the Santa Barbara Channel, California: U.S. Geological Survey Open-File Report 2017-1001 (OCS Study BOEM 2017-022), 76 p., http://doi.org/10.3133/ofr20171001.

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.

 

 

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).

 

A Marine Mammal Odyssey, Eh!

By Leila Lemos, PhD student

Dawn Barlow, MS student

Florence Sullivan, MS

The Society for Marine Mammalogy’s Biennial Conference on the Biology of Marine Mammals happens every two years and this year the conference took place in Halifax, Nova Scotia, Canada.

Logo of the Society for Marine Mammalogy’s 22nd Biennial Conference on the Biology of Marine Mammals, 2017: A Marine Mammal Odyssey, eh!

The conference started with a welcome reception on Sunday, October 22nd, followed by a week of plenaries, oral presentations, speed talks and posters, and two more days with different workshops to attend.

This conference is an important event for us, as marine mammalogists. This is the moment where we get to share our projects (how exciting!), get important feedback, and hear about different studies that are being conducted around the world. It is also an opportunity to network and find opportunities for collaboration with other researchers, and of course to learn from our colleagues who are presenting their work.

The GEMM Lab attending the opening plenaries of the conference!

The first day of conference started with an excellent talk from Asha de Vos, from Sri Lanka, where she discussed the need for increased diversity (in all aspects including race, gender, nationality, etc.) in our field, and advocated for the end of “parachute scientists” who come into a foreign (to them) location, complete their research, and then leave without communicating results, or empowering the local community to care or act in response to local conservation issues.  She also talked about the difficulty that researchers in developing countries face accessing research that is hidden behind journal pay walls, and encouraged everyone to get creative with communication! This means using blogs and social media, talking to science communicators and others in order to get our stories out, and no longer hiding our results behind the ivory tower of academia.  Overall, it was an inspirational way to begin the week.

On Thursday morning we heard Julie van der Hoop, who was this year’s recipient of the F.G. Wood Memorial Scholarship Award, present her work on “Drag from fishing gear entangling right whales: a major extinction risk factor”. Julie observed a decrease in lipid reserves in entangled whales and questioned if entanglements are as costly as events such as migration, pregnancy or lactation. Tags were also deployed on whales that had been disentangled from fishing gear, and researchers were able to see an increase in whale speed and dive depth.

Julie van der Hoop talks about different drag forces of fishing gears
on North Atlantic Right Whales.

There were many other interesting talks over the course of the week. Some of the talks that inspired us were:

— Stephen Trumble’s talk “Earplugs reveal a century of stress in baleen whales and the impact of industrial whaling” presented a time-series of cortisol profiles of different species of baleen whales using earplugs. The temporal data was compared to whaling data information and they were able to see a high correlation between datasets. However, during a low whaling season concurrent to the World War II in the 40’s, high cortisol levels were potentially associated to an increase in noise from ship traffic.

— Jane Khudyakov (“Elephant seal blubber transcriptome and proteome responses to single and repeated stress”) and Cory Champagne (“Metabolomic response to acute and repeated stress in the northern elephant seal”) presented different aspects of the same project. Jane looked at down/upregulation of genes (downregulation is when a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus; upregulation is the opposite: when the cell increases the quantity of cellular components) to check for stress. She was able to confirm an upregulation of genes after repeated stressor exposure. Cory checked for influences on the metabolism after administering ACTH (adrenocorticotropic hormone: a stimulating hormone that causes the release of glucocorticoid hormones by the adrenal cortex. i.e., cortisol, a stress related hormone) to elephant seals. By looking only at the stress-related hormone, he was not able to differentiate acute from chronic stress responses. However, he showed that many other metabolic processes varied according to the stress-exposure time. This included a decrease in amino acids, mobilization of lipids and upregulation of carbohydrates.

— Jouni Koskela (“Fishing restrictions is an essential protection method of the Saimaa ringed seal”) talked about the various conservation efforts being undertaken for the endangered Lake Saimaa ringed seal. Gill nets account for 90% of seal pup mortality, but if new pups can reach 20kg, only 14% of them will drown in these fishing net entanglements. Working with local industry and recreational interests, increased fishing restrictions have been enacted during the weaning season. In addition to other year-round restrictions, this has led to a small, but noticeable upward trend in pup production and population growth! A conservation success story is always gratifying to hear, and we wish these collaborative efforts continued future success.

— Charmain Hamilton (“Impacts of sea-ice declines on a pinnacle Arctic predator-prey relationship: Habitat, behaviour, and spatial overlap between coastal polar bears and ringed seals”) gave a fascinating presentation looking at how changing ice regimes in the arctic are affecting spatial habitat use patterns of polar bears. As ice decreases in the summer months, the polar bears move more, resulting in less spatial overlap with ringed seal habitat, and so the bears have turned to targeting ground nesting seabirds.  This spatio-temporal mismatch of traditional predator/prey has drastic implications for arctic food web dynamics.

— Nicholas Farmer’s presentation on a Population Consequences of Disturbance (PCoD) model for assessing theoretical impacts of seismic survey on sperm whale population health had some interesting parallels with new questions in our New Zealand blue whale project. By simulating whale movement through modeled three-dimensional sound fields, he found that the frequency of the disturbance (i.e., how many days in a row the seismic survey activity persisted) was very important in determining effects on the whales. If the seismic noise persists for many days in a row, the sperm whales may not be able to replenish their caloric reserves because of ongoing disturbance. As you can imagine, this pattern gets worse with more sequential days of disturbance.

— Jeremy Goldbogen used suction cup tags equipped with video cameras to peer into an unusual ecological niche: the boundary layer of large whales, where drag is minimized and remoras and small invertebrates compete and thrive. Who would have thought that at a marine mammal conference, a room full of people would be smiling and laughing at remoras sliding around the back of a blue whale, or barnacles filter feeding as they go for a ride with a humpback whale? Insights from animals that occupy this rare niche can inform improvements to current tag technologies.

The GEMM Lab was well represented this year with six different talks: four oral presentations and two speed talks! It is evident that all of our hard work and preparation, such as practicing our talks in front of our lab mates two weeks in advance, paid off.  All of the talks were extremely well received by the audience, and a few generated intelligent questions and discussion afterwards – exactly as we hoped.  It was certainly gratifying to see how packed the room was for Sharon’s announcement of our new method of standardizing photogrammetry from drones, and how long the people stayed to talk to Dawn after her presentation about an unique population of New Zealand blue whales – it took us over an hour to be able to take her away for food and the celebratory drinks she deserved!

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

 

GEMM Lab members at the closing celebration. From left to right: Florence Sullivan, Leila Lemos, Amanda Holdman, Solène Derville, and Dawn Barlow.
We are not always serious, we can get silly sometimes!

The weekend after the conference many courageous researchers who wanted to stuff their brains with even more specialized knowledge participated in different targeted workshops. From 32 different workshops that were offered, Leila chose to participate in “Measuring hormones in marine mammals: Current methods, alternative sample matrices, and future directions” in order to learn more about the new methods, hormones and matrices that are being used by different research groups and also to make connections with other endocrinologist researchers. Solène participated in the workshop “Reproducible Research with R, Git, and GitHub” led by Robert Shick.  She learned how to better organize her research workflow and looks forward to teaching us all how to be better collaborative coders, and ensure our analysis is reproducible by others and by our future selves!

On Sunday none of us from the GEMM Lab participated in workshops and we were able to explore a little bit of the Bay of Fundy, an important area for many marine mammal species. Even though we didn’t spot any marine mammals, we enjoyed witnessing the enormous tidal exchange of the bay (the largest tides in the world), and the fall colors of the Annaoplis valley were stunning as well. Our little trip was fun and relaxing after a whole week of learning.

The beauty of the Bay of Fundy.
GEMM Lab at the Bay of Fundy; from left to right: Kelly Sullivan (Florence’s husband and a GEMM Lab fan), Florence Sullivan, Dawn Barlow, Solène Derville, and Leila Lemos.
We do love being part of the GEMM Lab!

It is amazing how refreshing it is to participate in a conference. So many ideas popping up in our heads and an increasing desire to continue doing research and work for conservation of marine mammals. Now it’s time to put all of our ideas and energy into practice back home! See you all in two years at the next conference in Barcelona!

Flying out of Halifax!

A Little Slice of Heaven

Guest writer: Maggie O’Rourke-Liggett, GEMM Lab summer intern, Oregon State University,

One of the biggest obstacles an undergraduate can face is fulfilling the degree requirement of completing an internship or research opportunity. With almost every university and degree program requiring it for graduation and many employers requiring prior experience, the amount of pressure and competition is intense.

After being rejected from the internships I applied for earlier in the year, I heard about Dr. Leigh Torres’s research with the Geospatial Ecology of Marine Megafauna (GEMM) Lab . I decided to email her and ask if she had any open positions. Fast-forward a few weeks and I am collaborating with Florence Sullivan, a recent masters graduate from OSU, on the logistics of my Gray Whale Foraging Behavior internship with the GEMM Lab.

 

My workstation while I conduct photo identification analysis in the field station classroom. The photos are displayed and organized in Adobe Bridge. Source: Maggie O’Rourke-Liggett

During my time with the GEMM Lab team, I have been assisting with photo identification analysis of gray whales (Eschrichtius robustus), using a theodolite and Pythagoras computer program to track their movements, collecting samples of the zooplankton they eat, and recording other oceanographic data with our time-depth recorder. This project is hoping to identify the drivers of gray whale fine-scale foraging behavior.  For instance: Why do gray whales spend more time in some areas than others?  Does the type or density of prey affect their behavior? Do the whales use static features like kelp beds to help find their food? As a senior currently studying oceanography, who desires to study whale behavior in the future, this internship is like finding a gold mine.

Nathan Malamud, our other high school intern, and I working together to set up the theodolite in backyard during a practice run. Source: Florence Sullivan

Ever since day one at Hatfield Marine Science Center, I’ve been working with people who share the same passions for marine mammals as me. Spending hours upon hours sorting thousands of pictures may seem like a painful, tedious job, but knowing my work helps others to update existing identification catalogs makes it worthwhile. Plus, who wouldn’t want to look at whales all day?! After a while, you start to recognize specific individuals based on their various pigment configurations and scars. Once you can recognize individuals, it makes the sorting go by faster and helps with recognizing individual whales in the wild faster. It’s always exciting to sort through the photos and observe from the cliff or kayak and recognize a whale from the photo identification work.

After Florence taught me how to set up and operate the theodolite, a survey tool used to track a whale’s movements, we taught a class to undergrads on how to use it. I’ll never get over how people’s faces lit up when we discussed how the instrument works and its role in the overall mission.

Quince Nye, one of our high school interns, using side strokes to stabilize the kayak while I deploy our zooplankton net over the side with a down rigger. Source: Florence Sullivan

These past two weeks at OSU’s Port Orford Field Station have been like living on a little slice of heaven. My days are filled with clear views of the coast and the sound of waves crashing serve as a backdrop on my home for the month, the bed-and-breakfast turned field station. Each morning, the sun fills my room as I gather my gear for the day and help my teammates load the truck. We spend long days on the water collecting zooplankton samples and GoPro video or on the cliff recording whale behavior through the theodolite. To anyone searching for an internship and feeling burnt out from completing application after application, don’t give up. You’ll find your slice of heaven too.

The five senses of fieldwork

By Leila Lemos, PhD student

 

This summer was full of emotions for me: I finally started my first fieldwork season after almost a year of classes and saw my first gray whale (love at first sight!).

During the fieldwork we use a small research vessel (we call it “Red Rocket”) along the Oregon coast to collect data for my PhD project. We are collecting gray whale fecal samples to analyze hormone variations; acoustic data to assess ambient noise changes at different locations and also variations before, during and after events like the “Halibut opener”; GoPro recordings to evaluate prey availability; photographs in order to identify each individual whale and assess body and skin condition; and video recordings through UAS (aka “drone”) flights, so we can measure the whales and classify them as skinny/fat, calf/juvenile/adult and pregnant/non-pregnant.

However, in order to collect all of these data, we need to first find the whales. This is when we use our first sense: vision. We are always looking at the horizon searching for a blow to come up and once we see it, we safely approach the animal and start watching the individual’s behavior and taking photographs.

If the animal is surfacing regularly to allow a successful drone overflight, we stay with the whale and launch the UAS in order to collect photogrammetry and behavior data.

Each team member performs different functions on the boat, as seen in the figure below.

Figure 1: UAS image showing each team members’ functions in the boat at the moment just after the UAS launch.
Figure 1: UAS image showing each team members’ functions in the boat at the moment just after the UAS launch.

 

While one member pilots the boat, another operates the UAS. Another team member is responsible for taking photos of the whales so we can match individuals with the UAS videos. And the last team member puts the calibration board of known length in the water, so that we can later calculate the exact size of each pixel at various UAS altitudes, which allows us to accurately measure whale lengths. Team members also alternate between these and other functions.

Sometimes we put the UAS in the air and no whales are at the surface, or we can’t find any. These animals only stay at the surface for a short period of time, so working with whales can be really challenging. UAS batteries only last for 15-20 minutes and we need to make the most of that time as we can. All of the members need to help the UAS pilot in finding whales, and that is when, besides vision, we need to use hearing too. The sound of the whale’s respiration (blow) can be very loud, especially when whales are closer. Once we find the whale, we give the location to the UAS pilot: “whale at 2 o’clock at 30 meters from the boat!” and the pilot finds the whale for an overflight.

The opposite – too many whales around – can also happen. While we are observing one individual or searching for it in one direction, we may hear a blow from another whale right behind us, and that’s the signal for us to look for other individuals too.

But now you might be asking yourself: “ok, I agree with vision and hearing, but what about the other three senses? Smell? Taste? Touch?” Believe it or not, this happens. Sometimes whales surface pretty close to the boat and blow. If the wind is in our direction – ARGHHHH – we smell it and even taste it (after the first time you learn to close your mouth!). Not a smell I recommend.

Fecal samples are responsible for the 5th sense: touch!

Once we identify that the whale pooped, we approach the fecal plume in order to collect as much fecal matter as possible (Fig.2).

Figure 2: A: the poop is identified; B: the boat approaches the feces that are floating at the surface (~30 seconds); C: one of the team members remains at the bow of the boat to indicate where the feces are; D: another team member collects it with a fine-mesh net. Filmed under NOAA/NMFS permit #16111 to John Calambokidis).
Figure 2: A: the poop is identified; B: the boat approaches the feces that are floating at the surface (~30 seconds); C: one of the team members remains at the bow of the boat to indicate where the feces are; D: another team member collects it with a fine-mesh net. Filmed under NOAA/NMFS permit #16111 to John Calambokidis).

 

After collecting the poop we transfer all of it from the net to a small jar that we then keep cool in an ice chest until we arrive back at the lab and put it in the freezer. So, how do we transfer the poop to the jar? By touching it! We put the jar inside the net and transfer each poop spot to the jar with the help of water pressure from a squeeze bottle full of ambient salt water.

Figure 3: Two gray whale individuals swimming around kelp forests. Filmed under NOAA/NMFS permit #16111 to John Calambokidis).
Figure 3: Two gray whale individuals swimming around kelp forests. Filmed under NOAA/NMFS permit #16111 to John Calambokidis).

 

That’s how we use our senses to study the whales, and we also use an underwater sensory system (a GoPro) to see what the whales were feeding on.

GoPro video of mysid swarms that we recorded near feeding gray whales in Port Orford in August 2016:

Our fieldwork is wrapping up this week, and I can already say that it has been a success. The challenging Oregon weather allowed us to work on 25 days: 6 days in Port Orford and 19 days in the Newport and Depoe Bay region, totaling 141 hours and 50 minutes of effort. We saw 195 whales during 97 different sightings and collected 49 fecal samples. We also performed 67 UAS flights, 34 drifter deployments (to collect acoustic data), and 34 GoPro deployments.

It is incredible to see how much data we obtained! Now starts the second part of the challenge: how to put all of this data together and find the results. My next steps are:

– photo-identification analysis;

– body and skin condition scoring of individuals;

– photogrammetry analysis;

– analysis of the GoPro videos to characterize prey;

– hormone analysis laboratory training in November at the Seattle Aquarium

 

For now, enjoy some pictures and a video we collected during the fieldwork this summer. It was hard to choose my favorite pictures from 11,061 photos and a video from 13 hours and 29 minutes of recording, but I finally did! Enjoy!

Figure 4: Gray whale breaching in Port Orford on August 27th. (Photo by Leila Lemos; Taken under NOAA/NMFS permit #16111 to John Calambokidis).
Figure 4: Gray whale breaching in Port Orford on August 27th. (Photo by Leila Lemos; Taken under NOAA/NMFS permit #16111 to John Calambokidis).

 

Figure 5: Rainbow formation through sunlight refraction on the water droplets of a gray whale individual's blow in Newport on September 15th. (Photo by Leila Lemos; Taken under NOAA/NMFS permit #16111 to John Calambokidis).
Figure 5: Rainbow formation through sunlight refraction on the water droplets of a gray whale individual’s blow in Newport on September 15th. (Photo by Leila Lemos; Taken under NOAA/NMFS permit #16111 to John Calambokidis).

 

Likely gray whale nursing behavior (Taken under NOAA/NMFS permit #16111 to John Calambokidis):

Oceanus Day Three: Dolphin Delights

by Florence Sullivan, MSc student

Our third day aboard the Oceanus began in the misty morning fog before the sun even rose. We took the first CTD cast of the day at 0630am because the physical properties of the water column do not change much with the arrival of daylight. Our ability to visually detect marine mammals, however, is vastly improved with a little sunlight, and we wanted to make the best use of our hours at sea possible.

Randall Munroe www.XKCD.com

Our focus on day three was the Astoria canyon – a submarine feature just off the Oregon and Washington coast. Our first oceanographic station was 40 miles offshore, and 1300 meters deep, while the second was 20 miles offshore and only 170 meters deep.  See the handy infographic below to get a perspective on what those depths mean in the grand scheme of things.  From an oceanographic perspective, the neatest finding of the day was our ability to detect the freshwater plume coming from the Columbia River at both those stations despite their distance from each other, and from shore! Water density is one of the key characteristics that oceanographers use to track parcels of water as they travel through the ocean conveyor belt. Certain bodies of water (like the Mediterranean Sea, or the Atlantic or Pacific Oceans) have distinct properties that allow us to recognize them easily. In this case, it was very exciting to “sea” the two-layer system we had gotten used to observing overlain with a freshwater lens of much lower salinity, higher temperature, and lower density. This combination of freshwater, saltwater, and intriguing bathymetric features can lead to interesting foraging opportunities for marine megafauna – so, what did we find out there?

Click through link for better resolution: Randall Munroe www.XKCD.com/1040/large

Morning conditions were almost perfect for marine mammal observations – glassy calm with low swell, good, high, cloud cover to minimize glare and allow us to catch the barest hint of a blow….. it should come as no surprise then, that the first sightings of the day were seabirds and tuna!

I didn't catch any photos of the Tuna, so here's some mola mola we spotted. photo credit: Florence Sullivan
I didn’t catch any photos of the tuna, so here’s some sunfish we spotted. photo credit: Florence Sullivan

One of the best things about being at sea is the ability to look out at the horizon and have nothing but water staring back at you. It really drives home all the old seafaring superstitions about sailing off the edge of the world.  This close to shore, and in such productive waters, it is rare to find yourself truly alone, so when we spot a fishing trawler, there’s already a space to note it in the data log.  Ships at sea often have “follower” birds – avians attracted by easy meals as food scraps are dumped overboard. Fishing boats usually attract a lot of birds as fish bycatch and processing leftovers are flushed from the deck.  The birders groan, because identification and counts of individuals get more and more complicated as we approach other vessels.  The most thrilling bird sighting of the day for me were the flocks of a couple hundred fork-tailed storm petrels.

Fork-tailed storm petrels
Fork-tailed storm petrels. photo credit: Florence Sullivan

I find it remarkable that such small birds are capable of spending 80% of their life on the open ocean, returning to land only to mate and raise a chick. Their nesting strategy is pretty fascinating too – in bad foraging years, the chick is capable of surviving for several days without food by going into a state of torpor. (This slows metabolism and reduces growth until an adult returns.)

Just because the bird observers were starting to feel slightly overwhelmed, doesn’t mean that the marine mammal observers stopped their own survey.  The effort soon paid off with shouts of “Wait! What are those splashes over there?!” That’s the signal for everyone to get their binoculars up, start counting individuals, and making note of identifying features like color, shape of dorsal fin, and swimming style so that we can make an accurate species ID. The first sighting, though common in the area, was a new species for me – Pacific white sided dolphins!

Pacific white sided dolphin
A Pacific white sided dolphin leaps into view. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis

A pod of thirty or so came to ride our bow wake for a bit, which was a real treat. But wait, it got better! Shortly afterward, we spotted more activity off the starboard bow.  It was confusing at first because we could clearly see a lot of splashes indicating many individuals, but no one had glimpsed any fins to help us figure out the species. As the pod got closer, Leigh shouted “Lissodelphis! They’re lissodelphis!”  We couldn’t see any dorsal fins, because northern right whale dolphins haven’t got one! Then the fly bridge became absolute madness as we all attempted to count how many individuals were in the pod, as well as take pictures for photo ID. It got even more complicated when some more pacific white sided dolphins showed up to join in the bow-riding fun.

Northern right whale dolphins are hard to spot! photo credit: Florence Sullivan Taken under NMFS permit 16111 John Calambokidis
Northern right whale dolphins are hard to spot! photo credit: Florence Sullivan Taken under NMFS permit 16111 John Calambokidis

All told, our best estimates counted about 200 individuals around us in that moment. The dolphins tired of us soon, and things continued to calm down as we moved further away from the fishing vessels.  We had a final encounter with an enthusiastic young humpback who was breaching and tail-slapping all over the place before ending our survey and heading towards Astoria to make our dock time.

Humpback whale breach
Humpback whale breach. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis

As a Washington native who has always been interested in a maritime career, I grew up on stories of The Graveyard of the Pacific, and how difficult the crossing of the Columbia River Bar can be. Many harbors have dedicated captains to guide large ships into the port docks.  Did you know the same is true of the Columbia River Bar?  Conditions change so rapidly here, the shifting sands of the river mouth make it necessary for large ships to receive a local guest pilot (often via helicopter) to guide them across.  The National Motor Lifeboat School trains its students at the mouth of the river because it provides some of “the harshest maritime weather conditions in the world”.  Suffice it to say, not only was I thrilled to be able to detect the Columbia River plume in our CTD profile, I was also supremely excited to finally sail across the bar.  While a tiny part of me had hoped for a slightly more arduous crossing (to live up to all the stories you know), I am happy to report that we had glorious, calm, sunny conditions, which allowed us all to thoroughly enjoy the view from the fly bridge.

Cape Disappointment Lighthouse at the Columbia River Bar.
Cape Disappointment Lighthouse at the Columbia River Bar.

Finally, we arrived in Astoria, loaded all our gear into the ship’s RHIB (Ridged Hulled Inflatable Boat), lowered it into the river, descended the rope ladder, got settled, and motored into port. We waved goodbye to the R/V Oceanus, and hope to conduct another STEM cruise aboard her again soon.

Now if the ground would stop rolling, that would be just swell.

Last but not least, here are the videos we promised you in Oceanus Day Two – the first video shows the humpback lunge feeding behavior, while the second shows tail slapping. Follow our youtube channel for more cool videos!

 

Dredging and low visibility doesn’t stop us! We paddle on.

By: Catherine Lo, Research Intern, Oregon State University ‘16

Hello everyone! My name is Catherine Lo and I am a recent graduate from Oregon State University with a Bachelor’s of Science in Biology with a focus in Marine Biology. It has been an incredible whirlwind leading up to this point: long nights studying for finals, completing my degree, and planning the next steps for my future. I am fortunate to be working as a summer research intern for the GEMM Lab under the supervision of Dr. Leigh Torres and Msc. student Florence Sullivan in their research on the foraging ecology of gray whales. I have dreamed of working with marine mammals, potentially as a research veterinarian and so, capturing this position has been a great opportunity to begin my career.

The days go slow, but the weeks go fast. It’s already week 4 of our field season and the team and I are definitely in the groove of our research. The alarm(s) goes off at 5:00 AM…okay maybe closer to 5:30 AM (oops!), getting dressed for either the kayak or cliff based work, scarfing down breakfast that is usually a diet consisting of toast and peanut butter, and then heading off to the beach to launch the kayak. But this week it was different. A dredging event in Port Orford coordinated by the US Army Corps of Engineers is now taking place right next to the port’s jetty near our study site (Figure 1). This is an important process to move the sediment built up during the year in order for ships to safely navigate in and out of the port. We knew this was going to happen at some point over the summer, and worried that it might impact our research methods and objectives, but at the same time it offers some new opportunities: the chance to see how our GoPro and mysid sampling methods in Tichenor Cove are impacted by the sediment flow from the dredging activities.

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Figure 1. View of the dredger from the cliff field site in Port Orford.

My teammate Kelli and I were stationed on the cliff during the first deposit of sediment after the dredge’s first night and morning’s worth of scooping sand. None of us knew where the actual deposit site would be so we kept a good eye on it. The ship headed past the jetty. Turned around and, as a concerned feeling mustered within our field team, it began lowering the platform holding the sand just 250 yards away from our primary study site in Tichenor Cove! At this point, we knew things were going to be different in our samples. Unfortunately along with the sediment stirring up from dredging, we think a phytoplankton bloom is occurring simultaneously. Our GoPro footage lately has been rather clouded making it difficult to identify any mysid relative to our past footage. You can compare Figure 2 to the GoPro image found in Figure 2 of a previous post. It is times like these that we learn how dynamic the ocean is, how human activity can alter the ocean ecosystem, and how to adapt to changes, whether these adaptations are within our reach or not. We are interested to see how our sample sites will change again over time as the dredging operation finishes and the phytoplankton bloom ends.

Figure 2. This GoPro image taken in Tichenor Cove illustrates exactly how murky our view of the water column is with the sediment dredging operation in close proximity.
Figure 2. This GoPro image taken in Tichenor Cove illustrates exactly how murky our view of the water column is with the sediment dredging operation in close proximity.

Aside from the current water clarity situation, we’ve also had some exciting moments! Given how few whales we’ve seen thus far and how the ones we have tracked are predominately hanging by Mill Rocks, which is ~1km east of Tichenor Cove, Dr. Leigh Torres—our head advisor—thought it would be a good idea to check out the mysid scene over there to see what the attraction was. So, we sent our kayak team over there to conduct a few GoPro drops and zooplankton net tows and figure out what is so enticing for the whales.

While conducting this sampling work at Mill Rocks, I and my teammate were lucky enough to encounter a gray whale foraging. And believe me, we were going “off-the-walls” as soon as we heard from the cliff team and saw a blow as the whale surfaced nearby. It was one of those “best time of my life” moments where my dreams of kayaking this close to a whale came true. We fumbled around for our waterproof camera to get clear shots of its lateral flanks for photo identification while also trying to contain our excitement to a more decent level, and at the same time we had to make sure we were not in the whale’s path. There it was; surface after surface, we admired the immense size and beauty of a wild animal before our eyes. The worst part of it was when our camera battery died not long after taking a few pictures, but in a way it gave us a chance to really appreciate the existence of these animals. Note to self during research: always check your batteries are fully charged before heading out!

It baffles me how so often people walk along beaches or drive by without knowing an animal as incredible as this whale is just outside of the shoreline. Every time I’m inside pulling out time stamps or doing photo identification, I always think, “I wonder if there’s a whale in Tichenor Cove or at Mill Rocks right now…Yeah, there probably is one”. Alas, the data management work needs to be done and there’s always the next day for an opportunity of a sighting.

For a few days, our kayak team wasn’t able to work due to a small craft advisory. If you’ve ever been to Port Orford, you’d understand the severity of how windy it gets here. Ranging between 15 knots to 25 knots as early as 7am, so it gets rather difficult to maintain position at each of our sampling stations in our kayak. Fortunately our cliff team was able to set out. We were lucky to see a small whale foraging inside Tichenor Cove and later move onto Mill Rocks. This little one was giving us quite a show! Almost every time it came to the surface, defecation was observed shortly after. As unpleasant as feces might be, it can actually provide an abundance of information about a specific whale including sex, reproductive status, hormone levels, and much more. While doing our research, we are always keeping an eye out for signs of defecation in order to collect samples for another lab member’s PhD work. Here you can check out more information about Leila’s research. Figure 3 depicts a great image of defecation captured by our cliff team.

Figure 3. Gray whale defecating as it dives into the water in Tichenor Cove.
Figure 3. Gray whale defecating as it dives into the water in Tichenor Cove.
Figure 4. Gray whale swimming in Tichenor Cove taken by fellow intern Cathryn Wood.
Figure 4. Gray whale swimming in Tichenor Cove taken by fellow intern Cathryn Wood.

In addition to helping out Leila’s work, we recently began a collaboration with Aaron Galloway from The Oregon Institute of Marine Biology (OIMB). Aaron and his post-doc are looking at the fatty acid composition of mysid as an approach to eventually infer the diet of an aquatic animal. Check out his website which is linked to his name to learn more about the basis of his approach! While we collect mysid samples for them, in return they give us substantial information about the energy content of the mysid. This information on the energetic content of mysid will help the GEMM Lab answer questions about how much mysid gray whales need to eat.

Oregon State University and University of Oregon have a long-standing, intense rivalry. However, as an Alumna from Oregon State, I am amazed and thrilled to see how these two institutions can come together and collaborate. I mean, we’re all here for the same thing. Science, right? It creates the opportunity to apply integrative research by taking advantage of various expertise and resources. If we have those chances to reach out to others, why not make the most of it? In the end, sound science is what really matters, not rooting for the ducks or beavers.

My marine science background is based on my experiences looking at tidepools and hopping around on rocks to understand how vast intertidal communities range from invertebrates to algae. These experiences were an incredible part of my life, but now I look at the ocean unsure of what animals or environmental situations I might encounter. That’s what makes it so attractive. Don’t get me wrong. The intertidal will always hold a special place in my heart, but the endless possibilities of being a part of this marine mammal research team is priceless. I have learned so much about myself including my strengths and weaknesses. Living in Port Orford, which is a small coastal town with just a little over 1,000 people gives you a new perspective. The community has been very welcoming and I have appreciated how so much interest is placed on the kind of work we do. As I eat my nightly bowl of ice cream, I think about how, from here on out, the good and the bad can only bring a lifetime of skills and memories.

Figure 5. Me being extremely happy to be out on the kayak on a beautiful morning.
Figure 5. Me being extremely happy to be out on the kayak on a beautiful morning.