Marine Mammals Archives - Page 2 of 10 - Geospatial Ecology of Marine Megafauna Laboratory

Zooming in: A closer look at bottlenose dolphin distribution patterns off of San Diego, CA

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

Data analysis is often about parsing down data into manageable subsets. My project, which spans 34 years and six study sites along the California coast, requires significant data wrangling before full analysis. As part of a data analysis trial, I first refined my dataset to only the San Diego survey location. I chose this dataset for its standardization and large sample size; the bulk of my sightings, over 4,000 of the 6,136, are from the San Diego survey site where the transect methods were highly standardized. In the next step, I selected explanatory variable datasets that covered the sighting data at similar spatial and temporal resolutions. This small endeavor in analyzing my data was the first big leap into understanding what questions are feasible in terms of variable selection and analysis methods. I developed four major hypotheses for this San Diego site.

The study species: common bottlenose dolphin (Tursiops truncatus) seen along the California coastline in 2015. Image source: Alexa Kownacki.

Hypotheses:

H1: I predict that bottlenose dolphin sightings along the San Diego transect throughout the years 1981-2015 exhibit clustered distribution patterns as a result of the patchy distributions of both the species’ preferred habitats, as well as the social nature of bottlenose dolphins.

H2: I predict there would be higher densities of bottlenose dolphin at higher latitudes spanning 1981-2015 due to prey distributions shifting northward and less human activities in the northerly sections of the transect.

H3: I predict that during warm (positive) El Niño Southern Oscillation (ENSO) months, the dolphin sightings in San Diego would be distributed more northerly, predominantly with prey aggregations historically shifting northward into cooler waters, due to (secondarily) increasing sea surface temperatures.

H4: I predict that along the San Diego coastline, bottlenose dolphin sightings are clustered within two kilometers of the six major lagoons, with no specific preference for any lagoon, because the murky, nutrient-rich waters in the estuarine environments are ideal for prey protection and known for their higher densities of schooling fishes.

Data Description:

The common bottlenose dolphin (Tursiops truncatus) sighting data spans 1981-2015 with a few gap years. Sightings cover all months, but not in all years sampled. The same transect in San Diego was surveyed in a small, rigid-hulled inflatable boat with approximately a two-kilometer observation area (one kilometer surveyed 90 degrees to starboard and port of the bow).

I wanted to see if there were changes in dolphin distribution by latitude and, if so, whether those changes had a relationship to ENSO cycles and/or distances to lagoons. For ENSO data, I used the NOAA database that provides positive, neutral, and negative indices (1, 0, and -1, respectively) by each month of each year. I matched these ENSO data to my month-date information of dolphin sighting data. Distance from each lagoon was calculated for each sighting.

Figure 1. Map representing the San Diego transect, represented with a light blue line inside of a one-kilometer buffered “sighting zone” in pale yellow. The dark pink shapes are dolphin sightings from 1981-2015, although some are stacked on each other and cannot be differentiated. The lagoons, ranging in size, are color-coded. The transect line runs from the breakwaters of Mission Bay, CA to Oceanside Harbor, CA.

Results:

H1: True, dolphins are clustered and do not have a uniform distribution across this area. Spatial analysis indicated a less than a 1% likelihood that this clustered pattern could be the result of random chance (Fig. 1, z-score = -127.16, p-value < 0.0001). It is well-known that schooling fishes have a patchy distribution, which could influence the clustered distribution of their dolphin predators. In addition, bottlenose dolphins are highly social and although pods change in composition of individuals, the dolphins do usually transit, feed, and socialize in small groups.

Figure 2. Summary from the Average Nearest Neighbor calculation in ArcMap 10.6 displaying that bottlenose dolphin sightings in San Diego are highly clustered. When the z-score, which corresponds to different colors on the graphic above, is strongly negative (< -2.58), in this case dark blue, it indicates clustering. Because the p-value is very small, in this case, much less than 0.01, these results of clustering are strongly significant.

H2: False, dolphins do not occur at higher densities in the higher latitudes of the San Diego study site. The sightings are more clumped towards the lower latitudes overall (p < 2e^-16), possibly due to habitat preference. The sightings are closer to beaches with higher human densities and human-related activities near Mission Bay, CA. It should be noted, that just north of the San Diego transect is the Camp Pendleton Marine Base, which conducts frequent military exercises and could deter animals.

Figure 3. Histogram comparing the latitudes with the frequency of dolphin sightings in San Diego, CA. The x-axis represents the latitudinal difference from the most northern part of the transect to each dolphin sighting. Therefore, a small difference would translate to a sighting being in the northern transect areas whereas large differences would translate to sightings being more southerly. This could be read from left to right as most northern to most southern. The y-axis represents the frequency of which those differences are seen, that is, the number of sightings with that amount of latitudinal difference, or essentially location on the transect line. Therefore, you can see there is a peak in the number of sightings towards the southern part of the transect line.

H3: False, during warm (positive) El Niño Southern Oscillation (ENSO) months, the dolphin sightings in San Diego were more southerly. In colder (negative) ENSO months, the dolphins were more northerly. The differences between sighting latitude and ENSO index was significant (p<0.005). Post-hoc analysis indicates that the north-south distribution of dolphin sightings was different during each ENSO state.

Figure 4. Boxplot visualizing distributions of dolphin sightings latitudinal differences and ENSO index, with -1,0, and 1 representing cold, neutral, and warm years, respectively.

H4: True, dolphins are clustered around particular lagoons. Figure 5 illustrates how dolphin sightings nearest to Lagoon 6 (the San Dieguito Lagoon) are always within 0.03 decimal degrees. Because of how these data are formatted, decimal degrees is the easiest way to measure change in distance (in this case, the difference in latitude). In comparison, dolphins at Lagoon 5 (Los Penasquitos Lagoon) are distributed across distances, with the most sightings further from the lagoon.

Figure 5. Bar plot displaying the different distances from dolphin sighting location to the nearest lagoon in San Diego in decimal degrees. Note: Lagoon 4 is south of the study site and therefore was never the nearest lagoon.

I found a significant difference between distance to nearest lagoon in different ENSO index categories (p < 2.55e^-9): there is a significant difference in distance to nearest lagoon between neutral and negative values and positive and neutral years. Therefore, I hypothesize that in neutral ENSO months compared to positive and negative ENSO months, prey distributions are changing. This is one possible hypothesis for the significant difference in lagoon preference based on the monthly ENSO index. Using a violin plot (Fig. 6), it appears that Lagoon 5, Los Penasquitos Lagoon, has the widest variation of sighting distances in all ENSO index conditions. In neutral years, Lagoon 0, the Buena Vista Lagoon has multiple sightings, when in positive and negative years it had either no sightings or a single sighting. The Buena Vista Lagoon is the most northerly lagoon, which may indicate that in neutral ENSO months, dolphin pods are more northerly in their distribution.

Figure 6. Violin plot illustrating the distance from lagoons of dolphin sightings under different ENSO conditions. There are three major groups based on ENSO index: “-1” representing cold years, “0” representing neutral years, and “1” representing warm years. On the x-axis are lagoon IDs and on the y-axis is the distance to the nearest lagoon in decimal degrees. The wider the shapes, the more sightings, therefore Lagoon 6 has many sightings within a very small distance compared to Lagoon 5 where sightings are widely dispersed at greater distances.

Bottlenose dolphins foraging in a small group along the California coast in 2015. Image source: Alexa Kownacki.

Takeaways to science and management:

Bottlenose dolphins have a clustered distribution which seems to be related to ENSO monthly indices, and likely, their social structures. From these data, neutral ENSO months appear to have something different happening compared to positive and negative months, that is impacting the sighting distributions of bottlenose dolphins off the San Diego coastline. More research needs to be conducted to determine what is different about neutral months and how this may impact this dolphin population. On a finer scale, the six lagoons in San Diego appear to have a spatial relationship with dolphin sightings. These lagoons may provide critical habitat for bottlenose dolphins and/or for their preferred prey either by protecting the animals or by providing nutrients. Different lagoons may have different spans of impact, that is, some lagoons may have wider outflows that create larger nutrient plumes.

Other than the Marine Mammal Protection Act and small protected zones, there are no safeguards in place for these dolphins, whose population hovers around 500 individuals. Therefore, specific coastal areas surrounding lagoons that are more vulnerable to habitat loss, habitat degradation, and/or are more frequented by dolphins, may want greater protection added at a local, state, or federal level. For example, the Batiquitos and San Dieguito Lagoons already contain some Marine Conservation Areas with No-Take Zones within their reach. The city of San Diego and the state of California need better ways to assess the coastlines in their jurisdictions and how protecting the marine, estuarine, and terrestrial environments near and encompassing the coastlines impacts the greater ecosystem.

This dive into my data was an excellent lesson in spatial scaling with regards to parsing down my data to a single study site and in matching my existing data sets to other data that could help answer my hypotheses. Originally, I underestimated the robustness of my data. At first, I hesitated when considering reducing the dolphin sighting data to only include San Diego because I was concerned that I would not be able to do the statistical analyses. However, these concerns were unfounded. My results are strongly significant and provide great insight into my questions about my data. Now, I can further apply these preliminary results and explore both finer and broader scale resolutions, such as using the more precise ENSO index values and finding ways to compare offshore bottlenose dolphin sighting distributions.

Our GEM(M), Ruby, is back in action!

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

Every season, or significant period of time, usually has a distinct event that marks its beginning. For example, even though winter officially begins when the winter solstice occurs sometime between December 20 and December 23, many people often associate the first snowfall as the real start of winter. To mark the beginning of schooling, when children start 1^stgrade in Germany (which is where I’m from), they receive something called a “Zuckertüte”, which translated means “sugar bag”. It is a large (sometimes as large as the child) cone-shaped container made of cardboard filled with toys, chocolates, sweets, school supplies and various other treats topped with a large bow.

Receiving my Zuckertüte in August of 2001 before starting 1st grade. Source: Ines Hildebrand.

I still remember (and even have) mine – it was almost as tall as I was, had a large Barbie printed on it (and a real one sitting on top of it) and was bright pink. And of course, while at a movie theatre, once the lights dim completely and the curtain surrounding the screen opens just a little further, members of the audience stop chit-chatting or sending text messages, everyone quietens down and puts their devices away – the film is about to start. There are hundreds upon thousands of examples like these – moments, events, days that mark the start of something.

In the past, the beginning of summer has always been tied to two things for me: the end of school and the chance to be outside in the sun for many hours and days. This reality has changed slightly since moving to Oregon. While I don’t technically have any classes during the summer, the work definitely won’t stop. There are still dozens of papers to read, samples to run in the lab, and data points to plot. For anyone from Oregon or the Pacific Northwest (PNW), it’s pretty well known that the weather can be a little unpredictable and variable, meaning that summer might not always be filled with sunny days. Despite somewhat losing these two “summer markers”, I have found a new event to mark the beginning of summer – the arrival of the gray whales.

Their propensity for coastal waters and near-shore feeding is part of what makes gray whales so unique and arguably “easier” to study than some other baleen whale species. Image captured under NOAA/NMFS permit #21678. Source: Leigh Torres.

It’s official – the gray whale field season is upon us! As many of you may already know, the GEMM Lab has two active gray whale research projects: investigating the impacts of ocean noise on gray whale physiology and exploring potential individual foraging specialization among the Pacific Coast Feeding Group (PCFG) gray whales. Both projects involve field work, with the former operating out of Newport and the latter taking place in Port Orford, both collecting photographs and a variety of samples and tracklines to study the PCFG, which is a sub-group of the larger Eastern North Pacific (ENP) population. June 1^stis the widely accepted “cut-off date” for the PCFG whales, whereby gray whales seen after June 1^stalong the PNW coastline (specifically northern California, Oregon, Washington and British Columbia) are considered members of the PCFG. While this date is not the only qualifying factor for an individual to be considered a PCFG member, it is a good general rule of thumb. Since last week happened to be the first week of June, PI Leigh Torres, field technician Todd Chandler and myself launched out onto the Pacific Ocean in our trusty RHIB Ruby twice looking for gray whales, and it sure was a successful start to the season!

Even though I have done small boat-based field work before, every project and field team operates a little differently, which is why I was a little nervous at first. There are a lot of components to the Newport-based project as Leigh & co. assess gray whale physiology by collecting fecal samples, drone imagery and taking photographs, observing behavior patterns, as well as assessing local prey through GoPro footage and light traps. I wasn’t worried about the prey components of the research, since there is plenty of prey sampling involved in my Port Orford research, however I was worried about the whale side of things. I wasn’t sure whether I would be able to catch the drone as it returned back home to Ruby, fearing I might fumble and let it slip through my fingers. I also experienced slight déjà vu when handling the net we use to collect the fecal samples as I was forced to think back to some previous field work that involved collecting a biopsy dart with a net as well. During that project, I had somehow managed to get the end of the net stuck in the back of the boat and as I tried to scoop up the biopsy dart with the net-end, the pole became more and more stuck while the water kept dragging the net-end down and eventually the pole ended up snapping in my hands. On top of all this anxiety and work, trying to find your footing in a small RHIB like Ruby packed with lots of gear and a good amount of swell doesn’t make any of those tasks any easier.

However, as it turned out, none of my fears came to fruition. As soon as Todd fired up Ruby’s engine and we whizzed out and under the Newport bridge, I felt exhilarated. I love field work and was so excited to be out on the water again. During the two days I was able to observe multiple individuals of a species of whale that I find unique and fascinating.

Markings and pigmentation on the flukes are also unique to individuals and allow us to perform photo identification to track individuals over months and years. Image captured under NOAA/NMFS permit #21678. Source: Leigh Torres.

I felt back in my natural element and working with Leigh and Todd was rewarding and fun, as I have so much to learn from their years of experience and natural talent in the field dealing with stressful situations and juggling multiple components and gear. Even though I wasn’t out there collecting data for my own project, some of my observations did get me thinking about what I hope to focus on in my thesis – individualization. It is always interesting to see how differently whales will behave, whether due to the substrate we find them over, the water depths we find them in, or what their surfacing patterns are like. Although I still have six weeks to go until my field season starts and feel lucky to have the opportunity to help Leigh and Todd with the Newport field work, I am already looking forward to getting down to Port Orford in mid-July and starting the fifth consecutive gray whale field season down there.

But back to Newport – over the course of two days, we were able to deploy and retrieve one light trap to collect zooplankton, collect two fecal samples, perform two GoPro drops, fly the drone three times, and take hundreds of photos of whales. Leigh and Todd were both glad to be reunited with an old friend while I felt lucky to be able to meet such a famous lady – Scarback. A whale with a long sighting history not just for the GEMM Lab but for various researchers along the coast that study this population. Scarback is well-known (and easily identified) by the large concave injury on her back that is covered in whale lice, or cyamids. While there are stories about how Scarback’s wound came to be, it is not known for sure how she was injured. However, what researchers do know is that the wound has not stopped this female from reproducing and successfully raising several calves over her lifetime. After hearing her story from Leigh, I wasn’t surprised that both she and Todd were so thrilled to get both a fecal sample and a drone flight from her early in the season. The two days weren’t all rosy; most of day 1 was shrouded in a cloud of mist resulting in a thin but continuous layer of moisture forming on our clothes, while on day 2 we battled with some pretty big swells (up to 6 feet tall) and in typical Oregon coast style we were victims of a sudden downpour for about 10 minutes. We had some excellent sightings and some not-so-excellent sightings. Sightings where we had four whales surrounding our boat at the same time and sightings where we couldn’t re-locate a whale that had popped up right next to us. It happens.

A local celebrity – Scarback. Image captured under NOAA/NMFS permit #21678. Source: Lisa Hildebrand.

An ecstatic Lisa with wild hair standing in the bow pulpit of Ruby camera at the ready. Source: Leigh Torres.

Field work is certainly one of my favorite things in the world. The smell of the salt, the rustling of cereal bar wrappers, the whipping of hair, the perpetual rosy noses and cheeks no matter how many times you apply and re-apply sunscreen, the awkward hilarity of clambering onto the back of the boat where the engine is housed to take a potty break, the whooshing sound of a blow, the sometimes gentle and sometimes aggressive rocking of the boat, the realization that you haven’t had water in four hours only to chug half of your water in a few seconds, the waft of peanut butter and jelly sandwiches, the circular footprint where a whale has just gracefully dipped beneath the surface slipping away from view. I don’t think I will ever tire of any of those things.

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/ >

Marine Mammal Observing: Standardization is key

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

For the past two years, I’ve had the opportunity to be the marine mammal observer aboard the NOAA ship Bell M. Shimada for 10 days in May. Both trips covered transects in the Northern California Current Ecosystem during the same time of year, but things looked very different from my chair on the fly bridge. This trip, in particular, highlighted the importance of standardization, seeing as it was the second replicate of the same area. Other scientists and crew members repeatedly asked me the same questions that made me realize just how important it is to have standards in scientific practices and communicating them.

Northern right whale dolphin porpoising out of the water beside the ship while in transit. May 2019. Image source: Alexa Kownacki

The questions:

What do you actually do here and why are you doing it?
Is this year the same as last year in terms of weather, sightings, and transect locations?
Did you expect to see greater or fewer sightings (number and diversity)?
What is this Beaufort Sea State scale that you keep referring to?

All of these are important scientific questions that influence our hypothesis-testing research, survey methods, expected results, and potential conclusions. Although the entire science party aboard the ship conducted marine science, we all had our own specialties and sometimes only knew the basics, if that, about what the other person was doing. It became a perfect opportunity to share our science and standards across similar, but different fields.

Now, to answer those questions:

a) What do you actually do here and b) why are you doing it?

a) As the only marine mammal observer, I stand watch during favorable weather conditions while the ship is in transit, scanning from 0 to 90 degrees off the starboard side (from the front of the ship to a right angle towards the right side when facing forwards). Meanwhile, an application on an iPad called SeaScribe, records the ship’s exact location every 15 seconds, even when no animal is sighted. This process allows for the collection of absence data, that is, data when no animals are present. The SeaScribe program records the survey lines, along with manual inputs that I add, including weather and observer information. When I spot a marine mammal, I immediately mark an exact location on a hand held GPS, use my binoculars to identify the species, and add information to the sighting on the SeaScribe program, such as species, distance to the sighted animal(s), the degree (angle) to the sighting, number of animals in a group, behavior, and direction if traveling.

b) Marine mammal observing serves many different purposes. In this case, observing collects information about what species are where at what time. By piggy-backing on these large-scale, offshore oceanographic NOAA surveys, we have the unique opportunity to survey along standardized transect lines during different times of the year. From replicate survey data, we can start to form an idea of which species use which areas and what oceanographic conditions may impact species distributions. Currently there is not much consistent marine mammal data collected over these offshore areas between Northern California and Washington State, so our work is aiming to fill this knowledge gap.

Alexa observing on the R/V Shimada in May 2019, all bundled up. Image Source: Alexa Kownacki

What is this Beaufort Sea State scale that you keep referring to?

Great question! It took me a while to realize that this standard measuring tool to estimate wind speeds and sea conditions, is not commonly recognized even among other sea-goers. The Beaufort Sea State, or BSS, uses an empirical scale that ranges from 0-12 with 0 being no wind and calm seas, to 12 being hurricane-force winds with 45+ ft seas. It is frequently referenced by scientists in oceanography, marine science, and climate science as a universally-understood metric. The BSS was created in 1805 by Francis Beaufort, a hydrographer in the Royal Navy, to standardize weather conditions across the fleet of vessels. By the mid-1850s, the BSS was standardized to non-naval use for sailing vessels, and in 1916, expanded to include information specific to the seas and not the sails¹. We in the marine mammal observation field constantly collect BSS information while on survey to measure the quality of survey conditions that may impact our observations. BSS data allows us to measure the extent of our survey range, both in the distance that we are likely to sight animals and also the likelihood of sighting anything. Therefore, the BSS scale gives us an important indication of how much absence data we have collected, in addition to presence data.

A description of the Beaufort Sea State Scale. Image source: National Weather Service.

Is this year the same as last year in terms of weather, sightings, and transect locations?

The short answer is no. Observed differences in marine mammal sightings in terms of both species diversity and number of animals between years can be normal. There are many potential explanatory variables, from differences in currents, upwelling strength, El Nino index levels, water temperatures, or, what was obvious in this case: sighting conditions. The weather in May 2019 varied greatly from that in May 2018. Last year, I observed for nearly every day because the Beaufort Sea State (BSS) was frequently less than a four. However, this year, more often than not, the BSS greater than or equal to five. A BSS of 5 equates to approximately 17-21 knots of breeze with 6-foot waves and the water appears to have many “white horses” or pronounced white caps with sea spray. Additionally, mechanical issue with winches delayed and altered our transect locations. Therefore, although multiple transects from May 2018 were also surveyed during May 2019, there were a few lines that do not have data for both cruises.

Did you expect to see greater or fewer sightings (number and diversity)?

Knowing that I had less favorable sighting conditions and less amount of effort observing this year, it is not surprising that I observed fewer marine mammals in total count and in species diversity. Even less surprising is that on the day with the best weather, where the BSS was less than a five, I recorded the most sightings with the highest species count. May 2018 felt a bit like a tropical vacation because we had surprisingly sunny days with mild winds, and during May 2019 we had some rough seas with gale force winds. Additionally, as an observer, I need to remove as much bias as possible. So, yes, I had hoped to see beaked whales or orca like I did in May 2018, but I was still pleasantly surprised when I spotted fin whales feeding in May 2019.

Marine Mammal Species	Number of Sightings
	May 2018	May 2019
Humpback whale	31	6
Northern right whale dolphin	1	2
Pacific white-sided dolphin	3	6
UNID beaked whale	1	0
Cuvier’s beaked whale	1	0
Gray whale	4	1
Minke whale	1	1
Fin whale	4	1
Blue whale	1	0
Transient killer whale	1	0
Dall’s porpoise	2	0
Northern fur seal	1	0
California sea lion	0	1

Pacific white-sided dolphin. Image source: Alexa Kownacki

Standardization is a common theme. Observing between years on standard transects, at set speeds, in different conditions using standardized tools is critical to collecting high quality data that is comparable across different periods. Scientists constantly think about quality control. We look for trends and patterns, similarities and differences, but none of those could be understood without having standard metrics.

The entire science party aboard the R/V Shimada in May 2019, including a marine mammal scientist, phytoplankton scientists, zooplankton scientists, and fisheries scientists, and oceanographers. Image Source: Alexa Kownacki

Literature Cited:

¹Oliver, John E. (2005). Encyclopedia of world climatology. Springer.

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.

More data, more questions, more projects: There’s always more to learn

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

As you may have read in previous blog posts, my research focuses on the ecology of blue whales in New Zealand. Through my MS research and years of work by a dedicated team, we were able to document and describe a population of around 700 blue whales that are unique to New Zealand, present year-round, and genetically distinct from all other known populations [1]. While this is a very exciting discovery, documenting this population has also unlocked a myriad of further questions about these whales. Can we predict when and where the whales are most likely to be? How does their distribution change seasonally? How often do they overlap with anthropogenic activity? My PhD research will aim to answer these questions through models of blue whale distribution patterns relative to their environment at multiple spatial and temporal scales.

Because time at sea for vessel-based surveys is cost-limited and difficult to come by, it is in any scientist’s best interest to collect as many concurrent streams of data as possible while in the field. When Dr. Leigh Torres designed our blue whale surveys that were conducted in 2014, 2016, and 2017, she really did a miraculous job of maximizing time on the water. With more data, more questions can be asked. These complimentary datasets have led to the pursuit of many “side projects”. I am lucky enough to work on these questions in parallel with what will form the bulk of my PhD, and collaborate with a number of people in the process. In this blog post, I’ll give you some short teasers of these “side projects”!

Surface lunge feeding as a foraging strategy for New Zealand blue whales

Most of what we know about blue whale foraging behavior comes from studies conducted off the coast of Southern California[2,3] using suction cup accelerometer tags. While these studies in the California Current ecosystem have led to insights and breakthroughs in our understanding of these elusive marine predators and their prey, they have also led us to adopt the paradigm that krill patches are denser at depth, and blue whales are most likely to target these deep prey patches when they feed. We have combined our prey data with blue whale behavioral data observed via a drone to investigate blue whale foraging in New Zealand, with a particular emphasis on surface feeding as a strategy. In our recent analyses, we are finding that in New Zealand, lunge feeding at the surface may be more than just “snacking”. Rather, it may be an energetically efficient strategy that blue whales have evolved in the region with unique implications for conservation.

Figure 1. A blue whale lunges on an aggregation of krill. UAS piloted by Todd Chandler.

Combining multiple data streams for a comprehensive health assessment

In the field, we collected photographs, blubber biopsy samples, fecal samples, and conducted unmanned aerial system (UAS, a.k.a. “drone”) flights over blue whales. The blubber and fecal samples can be analyzed for stress and reproductive hormone levels; UAS imagery allows us to quantify a whale’s body condition[4]; and photographs can be used to evaluate skin condition for abnormalities. By pulling together these multiple data streams, this project aims to establish a baseline understanding of the variability in stress and reproductive hormone levels, body condition, and skin condition for the population. Because our study period spans multiple years, we also have the ability to look at temporal patterns and individual changes over time. From our preliminary results, we have evidence for multiple pregnant females from elevated pregnancy and stress hormones, as well as apparent pregnancy from the body condition analysis. Additionally, a large proportion of the population appear to be affected by blistering and cookie cutter shark bites.

Figure 2. An example aerial drone image of a blue whale that will be used to asses body condition, i.e. how healthy or malnourished the whale is. (Drone piloted by Todd Chandler).

Figure 3. Images of blue whale skin condition, affected by A) blistering and B) cookie cutter shark bites.

Comparing body shape and morphology between species

The GEMM Lab uses UAS to quantitatively study behavior[5] and health of large whales. From various projects in different parts of the world we have now assimilated UAS data on blue, gray, and humpback whales. We will measure these images to investigate differences in body shape and morphology among these species. We plan to explore how form follows function across baleen whales, based on their different life histories, foraging strategies, and ecological roles.

Figure 4 . Aerial images of A) a blue whale in New Zealand’s South Taranaki Bight, B) a gray whale off the coast of Oregon, and C) a humpback whale off the coast of Washington. Drone piloted by Todd Chandler (A and B) and Jason Miranda (C).

So it goes—my dissertation will contain a series of chapters that build on one another to explore blue whale distribution patterns at increasing scales, as well as a growing number of appendices for these “side projects”. Explorations and collaborations like I’ve described here allow me to broaden my perspectives and diversify my analytical skills, as well as work with many excellent teams of scientists. The more data we collect, the more questions we are able to ask. The more questions we ask, the more we seem to uncover that is yet to be understood. So stay tuned for some exciting forthcoming results from all of these analyses, as well as plenty of new questions, waiting to be posed.

References

Barlow DR et al. 2018 Documentation of a New Zealand blue whale population based on multiple lines of evidence. Endanger. Species Res. 36, 27–40. (doi:https://doi.org/10.3354/esr00891)
Hazen EL, Friedlaender AS, Goldbogen JA. 2015 Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density. Sci. Adv. 1, e1500469–e1500469. (doi:10.1126/sciadv.1500469)
Goldbogen JA, Calambokidis J, Oleson E, Potvin J, Pyenson ND, Schorr G, Shadwick RE. 2011 Mechanics, hydrodynamics and energetics of blue whale lunge feeding: efficiency dependence on krill density. J. Exp. Biol. 214, 131–146. (doi:10.1242/jeb.048157)
Burnett JD, Lemos L, Barlow DR, Wing MG, Chandler TE, Torres LG. 2018 Estimating morphometric attributes on baleen whales using small UAS photogrammetry: A case study with blue and gray whales. Mar. Mammal Sci. (doi:10.1111/mms.12527)
Torres LG, Nieukirk SL, Lemos L, Chandler TE. 2018 Drone Up! Quantifying Whale Behavior From a New Perspective Improves Observational Capacity. Front. Mar. Sci. 5. (doi:10.3389/fmars.2018.00319)

Signs you’re an ecologist – you don’t spend nearly enough time geeking out about your study species…

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

This past week has been very busy for me as I gave three quite important, yet very different, presentations. The first was on Tuesday at the Pacific High School in Port Orford, near my study site. The aim of the game was recruitment – my quest for two eager local high schoolers to be my interns for this 2019 summer field season has begun (read blogs written by our 2017 HS interns Nathan Malamud and Quince Nye)! I was lucky enough to be given an entire class period to talk to the students and so I hope that the picture I painted of kayaks, gray whales and sun will be enough to entice students to apply to the internship.

The second was a short presentation in one of the classes I took this term, GEOG 561: GIScience II Analysis and Applications. The class focuses on developing and conducting geospatial analyses in R and throughout the term each student develops a small independent research project using some of their own data. For my research project, I decided to do a small cluster analysis of the zooplankton community data that we have collected from the kayak net samples.

The third and final presentation of the week happened on Thursday and marked one of the big milestones on my Master’s journey: my research review. The research review is a mandatory (and extremely helpful) process in the Department of Fisheries & Wildlife where the student (in this case me), the committee (Dr Leigh Torres, Dr Rachael Orben, Dr Kim Bernard and Dr Susanne Brander) and a department representative (Dr Brian Sidlauskas) all assemble to discuss the student’s research proposal, which lays out the intended work, chapters, analysis and timeline for the students’ thesis. My proposal (which currently bears the title: “Tonight’s specials include mysids, gammarids and more: An examination of the zooplankton prey of Oregon gray whales and its impact on individual foraging patterns”) proposes a two-chapter thesis where the first examines the quality of zooplankton prey, while the second looks at potential individual foraging specialization of gray whales along the Oregon coast. While my entire committee agreed that what I have set forth to do in the next two or so years is ambitious, they provided me with excellent feedback and confidence that I would be able to achieve what I have planned.

Now that it’s the weekend and I’ve had some time to sit back and think about the week, I realized one major commonality between all three presentations I gave. None of the Powerpoints featured more than one image of a gray whale. How could this be?! It is after all my study species and I spend so much of my summer looking at them – how could it be that so little of what I showed and talked about was the thing that I am most passionate about and is so central to my research?

In the course of doing research, it’s easy to get wound up in the nitty gritty and forget about the big picture. While the nitty gritty is also imperative to conducting the research (and ultimately getting results), I sometimes forget about why I do what I do, which is that gray whales are AWESOME. Looking into the past, it seems that some of my lab mates have had the same realizations about their study species before too: see here and here. So for this blog, I want to bring it back to basics and share some of the things that I think are most fascinating about gray whales.

Gray whales are the only baleen whale that feeds benthically. This behavior is facilitated by the shorter and tougher baleen that gray whales possess in comparison to other baleen whale species (Pivorunas 1979). The majority of the Eastern North Pacific (ENP) gray whale population feeds benthically in the Bering Sea where they eat ampeliscid amphipods, which are a type of benthic invertebrates (Nerini 1984). It is estimated that gray whales must regain 11-29% of critical body mass during the feeding season (Villegas-Amtmann et al. 2015) in order to obtain the energy stores they require for the entire year. Besides the personal benefit of sea floor foraging, by using this feeding tactic gray whales create depressions in the soft sediment that benefit other species besides themselves. The highly disruptive nature of this action can increase the biodiversity of the seafloor and initiate scavenging events by lysiannassid amphipods on other infauna (Oliver & Slattery 1985). Furthermore, Grebmeier & Harrison (1992) documented that a variety of seabirds including northern fulmars, black-legged kittiwakes and thick-billed murres feed on benthic amphipods brought to the surface by this unique foraging behavior performed by gray whales.

Gray whales are essentially acrobats. A preference for benthic prey goes hand in hand with a preference for shallow, coastal waters, as for example Pacific Coast Feeding Group gray whales tend to forage within the 5-15 m depth range (Weller et al. 1999). With female adults ranging between 13-15 m in length (females tend to be slightly larger than adult males) and weighing anywhere between 15-33 tons (Jones et al. 1984), I am continuously fascinated by how gracefully and slowly gray whales can navigate extremely shallow waters.

However, it is more than just simple navigation – the behaviors and moves that some gray whales display while in the shallows is phenomenal too. Last year Torres et al. (2018) documented this agility through unmanned aerial systems (UAS) footage that provided evidence for some novel foraging tactics including headstands, side-swimming, and jaw snapping and flexing.

They sure are resilient. Commercial whaling of gray whales began in 1846 after two commercial whaling vessels first discovered the winter breeding grounds in Baja California, Mexico (Henderson 1984). Following this discovery, the ENP were targeted for roughly a century before receiving full protection under the International Convention for the Regulation of Whaling in 1946 (Reeves 1984). Through genetic analyses, it has been estimated that the pre-whaling abundance of the ENP population was between 76,000 – 118,000 individuals (Alter et al. 2012), which is roughly three to five times larger than current estimates (24,000 – 26,000; Scordino et al. 2018). While the gray whale populations that once existed in the Atlantic Ocean were not as fortunate as those in the Pacific (Atlantic gray whales were declared extinct in the 18^thcentury due to extensive whaling; Bryant 1995), the ENP has definitely made a strong comeback. Additionally, gray whale resilience is not only evident on this long temporal scale but it can also be seen annually when gray whale mothers fight relentlessly to keep their calves alive when under attack from killer whales. A study on predation of gray whales by transient killer whales in Alaska reported that attacks were quickly abandoned if calves were aggressively defended by their mothers or if gray whales succeeded in reaching depths of 3 m or less (Barrett-Lennard et al. 2011).

For some unimaginable reason, gray whales appear to feel a strong connection to us. For many, gray whales might be best known for actively seeking out human contact during their breeding season in the Mexican lagoons. I find this actuality particularly interesting because of the bloody history we share with Pacific gray whales.

Those are just some of the things about gray whales that make them so fascinating to me. I look forward to potentially discovering one or two more things that we don’t know about them yet through my research. Even if that doesn’t turn out to be the case, I feel so lucky that I at least get to spend so much time with them during their feeding season here along the Oregon coast.

References

Alter, E.S., et al., Pre-whaling genetic diversity and population ecology in Eastern Pacific gray whales: Insights from ancient DNA and stable isotopes.PLoS ONE, 2012. doi.org/10.1371/journal.pone.0035039.

Barrett-Lennard, L.G., et al., Predation on gray whales and prolonged feeding on submerged carcasses by transient killer whales at Unimak Island, Alaska. Marine Ecology Progress Series, 2011. 421: 229-241.

Bryant, P.J., Dating remains of gray whales from the Eastern North Atlantic. Journal of Mammalogy, 1995. 76(3): 857-861.

Grebmeier, J.M., & Harrison, N.M., Seabird feeding on benthic amphipods facilitated by gray whale feeding activity in the northern Bering Sea. Marine Ecology Progress Series, 1992. 80: 125-133.

Henderson, D.A., Nineteenth century gray whaling: Grounds, catches and kills, practices and depletion of the whale population.Pages 159-186 inJones, M.L. et al., eds. The gray whale: Eschrichtius robustus, 1984. Academic Press, Orlando.

Jones, M.L., et al., The gray whale: Eschrichtius robustus. 1984. Academic Press, Orlando.

Nerini, M., A review of the gray whale feeding ecology. Pages 423-448 inJones, M.L. et al., eds. The gray whale: Eschrichtius robustus, 1984. Academic Press, Orlando.

Oliver, J.S., & Slattery, P.N., Destruction and obstruction on the sea floor: effects of gray whale feeding.Ecology, 1985. 66: 1965-1975.

Pivorunas, A., The feeding mechanisms of baleen whales.American Scientist, 1979. 67(4): 432-440.

Reeves, R.R., Modern commercial pelagic whaling for gray whales. Pages 187-200 inJones, M.L. et al., eds. The gray whale: Eschrichtius robustus, 1984. Academic Press, Orlando.

Scordino, J., et al., Report of gray whale implementation review coordination call on 5 December 2018.

Torres, L.G., et al., Drone up! Quantifying whale behavior from a new perspective improves observational capacity.Frontiers in Marine Science, 2018. 5: doi:10.3389/fmars.2018.00319.

Villegas-Amtmann, S., et al., A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales. Ecosphere, 2015. 6(10): 1-19.

Weller, D.W., et al., Gray whale (Eschrichtius robustus) off Sakhalin Island, Russia: Seasonal and annual patterns of occurrence. Marine Mammal Science, 1999. 15(4): 1208-1227.

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.

Plastics truly are ubiquitous in the marine environment

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

As I enter my second term at OSU as a Master’s student, the ideas and structure of my thesis are slowly coming together. As of right now, my plan is to have two data chapters: The first chapter will assess the quality of zooplankton prey gray whales have access to along the Oregon coast, by looking at energetic value and microplastic content. I will contemplate about how my results potentially affect gray whale health. The second chapter will investigate fine-scale foraging and space use of gray whales in the Port Orford area to determine whether individual specialisation exists.

Fig 1. What it feels like when you start a literature review. Source: Harvard Blogs.

When I first started digging into the scientific literature to prepare for writing my thesis proposal (which is still underway but I’m getting close to the end of a first draft…), one sentence that I seemed to stumble across more often than not was “Marine plastics are ubiquitous” or “Plastics have become ubiquitous in the marine environment” or some other, very similar, iteration of that statement (e.g. Machovsky-Capuska et al. 2019; Eriksen et al. 2014; Fendall & Sewell 2009).

Many of the papers I first read were review papers on microplastics that mostly discussed general concepts like dispersal mechanisms, trophic transfer, or how microplastics become degraded. While I often think of review papers as treasure chests, since they neatly and succinctly summarise an often complicated and busy area of research into just a few pages, sometimes the fine-scale detail can go missing. Therefore, when reading these review papers, I wasn’t learning the in depth details about specific studies where microplastics had been detected in a group of individuals, population or species. So I felt the statement “Plastics are ubiquitous” was just a good (and pretty dramatic) opening line for a paper. However, once I delved into the studies on single species, I was overwhelmed by the amount of results that GoogleScholar spit out at me. If you type “microplastics marine” into the search bar, you’ll get about 7,650 results. This amount might not sound like a lot, especially if you compare it to say “gray whale”, which generates 96,600 results. Yet, the microplastic extraction method typically used was only developed in 2004 (Thompson et al. 2004). Hence, in a span of just 15 years, over 7,000 studies have detected microplastics in over 660 marine organisms (Secretariat of the Convention on Biological Diversity 2012) – a fact I find extremely troubling.

Fig 2. Graphic explaining how plastics don’t go away. Source: Biotecnika.

Microplastics are most commonly viewed as particles <5 mm in size (though there is some contention on this size classification, e.g. Claessens et al. 2013). Microplastics arise from several sources, including fragmentation of larger plastics by UV photo-degradation, wave action and physical abrasion, loss of pre-production pellets (nurdles) and polystyrene beads from shipping vessels, waste water discharge containing microbeads used in cosmetics and microfibers released during the washing of textiles and run-off from land (Nelms et al. 2018). Their small size makes these persistent particles bioavailable to ingestion by a variety of marine taxa, ranging from small prey organisms such as zooplankton, to large megafauna such as whales.

Zooplankton are at the base of marine food webs and are therefore consumed in large quantities by a large number of consumers. The propensity of zooplankton to feed in surface waters makes them highly susceptible to encountering and ingesting microplastics as this is where these synthetic particles are highly abundant (Botterell et al. 2018). Microplastics have been detected in zooplankton from the Northeast Pacific Ocean (Desforges et al. 2015), northern South China Sea (Sun et al. 2017), and Portuguese coast (Frias et al. 2014). Additionally, there is documented overlap between microplastic and zooplankton occurrence at many more locations (e.g. North Western Mediterranean Sea, Collignon et al. 2012; Baltic Sea, Gorokhova 2015; Arctic Ocean, Lusher et al. 2015a). As microplastics research is still in its relative infancy, the extent to which microplastics are ingested by zooplankton and the consequences of this behaviour are uncertain. Nevertheless, exposure to microplastics could lead to entanglement of particles within feeding appendages and/or block internal organs, which may result in reduced feeding, poor overall health, injury and death (Desforges et al. 2015). Though a lab study has found that microplastics are expelled by zooplankton after ingestion, the gut-retention times varied between species, and there is the potential risk of exposure to toxins that leech off of particles while in the body (Cole et al. 2013; the below video is from the afore-mentioned study showing how plankton eat plastics, which are illuminated in fluorescent green).

The large knowledge gap regarding the health implications indicates a strong need for more laboratory studies that investigate the long-term effects of persistent exposure to microplastics on lower trophic organisms, as well as continued short-term experiments that examine whether different zooplankton species are affected differently, since morphologies and life-histories vary widely.

Let’s take a step back and re-focus our lens onto a marine taxa that is much, much bigger in size than a zooplankton: cetaceans. Plastic debris has been documented in the stomachs of stranded individuals of several cetacean species (See Baulch & Perry 2014 for a review), however findings of microplastics in cetaceans are less common. Since cetaceans consume large amounts of prey a day, up to several tons daily for some baleen whales, the likelihood that they are ingesting microplastics through their prey is relatively high (Nelms et al. 2018). Therefore the low number of reported cases is again likely due to the relative novelty of microplastic detection methods. Despite the paucity of studies, microplastics have been found in a True’s beaked whale (Mesoplodon mirus, Lusher et al. 2015b), a humpback whale (Megaptera novaeangliae, Besseling et al. 2015) and an Indo-Pacific humpback dolphin (Sousa chinensis, Zhu et al. 2018), showing that microplastic ingestion by cetaceans does occur. Whether these individuals actively (i.e. active feeding) or passively (i.e. uptake through prey consumption) consumed the microplastics, or inhaled them at the water-air interface, is unknown. As with zooplankton, the short- and long-term impacts of ingesting microplastics by marine mammals is also unknown, though impacts on survival, feeding and uptake of toxins are all possibilities.

Fig 3. Example of a light trap sample collected off the Newport coast. Source: L. Torres.

The data collection and analysis I am doing for my thesis will hopefully fill small pockets in these large knowledge gaps. I hope to be able to quantify the extent of microplastic pollution among zooplankton species in nearshore Oregon waters. By comparing samples from several years, months and locations, I will determine whether microplastic loads vary spatially and temporally. Since their abundance and presence have been described as being patchy due to the influence of oceanographic and weather conditions (GESAMP 2016), it would seem reasonable to assume that there will be variation. But, results are a ways away as we have not even started our microplastic extraction techniques, which involves digesting samples in potassium hydroxide solution, incubating them at 50ºC for 48-72 hours, sorting through the dissolved material to identify potential plastics and sending them away for analysis. We first have to work our way through jars upon jars of unopened zooplankton light trap samplesthat need to be sorted by species. I am thankfully joined by undergraduate Robyn Norman who has already assisted this project immensely over the last two years with her zooplankton sorting prowess. So in case anyone wants to come looking for us over the next few weeks, you’ll find both Robyn and me sitting in front of a laminar flow hood in the lab of ecotoxicologist Dr. Susanne Brander, with whom we are collaborating on the microplastics portion of my thesis.

References

Baulch, S., & Perry, C., Evaluating the impacts of marine debris on cetaceans. Marine Pollution Bulletin, 2014. 80(1-2): 210-221.

Besseling, E., et al., Microplastic in a macro filter feeder: humpback whale Megaptera novaeangliae. Marine Pollution Bulletin, 2015. 95: 248-252.

Botterell, Z.L.R., et al., Bioavailability and effects of microplastics on marine zooplankton: a review. Environmental Pollution, 2018. 245: 98-110.

Claessens, M., et al., New techniques for the detection of microplastics in sediments and field collected organisms. Marine Pollution Bulletin, 2013. 70(1-2): 227-233.

Cole, M., et al., Microplastic ingestion by zooplankton. Environmental Science & Technology, 2013. 47(12): 6646-6655.

Collignon, A., et al., Neustonic microplastic and zooplankton in the North Western Mediterranean Sea. Marine Pollution Bulletin, 2012. 64(4): 861-864.

Desforges, JP.W., et al., Ingestion of microplastics by zooplankton in the Northeast Pacific Ocean. Archives of Environmental Contamination and Toxicology, 2015. 69(3): 320-330.

Eriksen, M., et al., Plastic pollution in the world’s oceans: more than 5 trillion plastic pieces weighing over 250,000 tons afloat at sea. PLoS ONE, 2014. doi.org/10.1371/journal.pone.0111913.

Fendall, L.S., & Sewell, M.A., Contributing to marine pollution by washing your face: microplastics in facial cleansers. Marine Pollution Bulletin, 2009. 58(8): 1225-1228.

Frias, J.P.G.L., et al., Evidence of microplastics in samples of zooplankton from Portuguese coastal waters. Marine Environmental Research, 2014. 95: 89-95.

GESAMP, Sources, fates and effects of microplastics in the marine environment: part 2 of a global assessment. Second United Nations Environment Assembly, 2016. http://www.gesamp.org/site/assets/files/1720/rs93e.pdf

Gorokhova, E., Screening for microplastic particles in plankton samples: how to integrate marine litter assessment into existing monitoring programs? Marine Pollution Bulletin, 2015. 99(1-2): 271-275.

Lusher, A.L., et al., Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples. Scientific Reports, 2015a. 5: 14947.

Lusher, A.L., et al., Microplastic and macroplastic ingestion by a deep diving, oceanic cetacean: the True’s beaked whales Mesoplodon mirus. Environmental Pollution, 2015b. 199: 185-191.

Machovsky-Capuska, G.E., et al., A nutritional perspective on plastic ingestion in wildlife. Science of the Total Environment, 2019. 656: 789-796.

Nelms, S.E., et al., Investigating microplastic trophic transfer in marine top predators. Environmental Pollution, 2018. 238: 999-1007.

Secretariat of the Convention on Biological Diversity and the Scientific and Technical Advisory Panel – GEF (2012), Impacts of marine debris on biodiversity: current status and potential solutions. Montreal, Technical Series. 67: 1-61.

Sun, X., et al., Ingestion of microplastics by natural zooplankton groups in the northern South China Sea. Marine Pollution Bulletin, 2017. 115(1-2): 217-224.

Thompson, R.C., et al., Lost at sea: where is all the plastic? Science, 2004. 304(5672): 838.

Zhu, J., et al., Cetaceans and microplastics: First report of microplastic ingestion by a coastal delphinid, Sousa chinensis. Science of the Total Environment, 2018. 659: 649-654.

Science (or the lack thereof) in the Midst of a Government Shutdown

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

In what is the longest government shutdown in the history of the United States, many people are impacted. Speaking from a scientist’s point of view, I acknowledge the scientific community is one of many groups that is being majorly obstructed. Here at the GEMM Laboratory, all of us are feeling the frustrations of the federal government grinding to a halt in different ways. Although our research spans great distances—from Dawn’s work on New Zealand blue whales that utilizes environmental data managed by our federal government, to new projects that cannot get federal permit approvals to state data collection, to many of Leigh’s projects on the Oregon coast of the USA that are funded and collaborate with federal agencies—we all recognize that our science is affected by the shutdown. My research on common bottlenose dolphins is no exception; my academic funding is through the US Department of Defense, my collaborators are NOAA employees who contribute NOAA data; I use publicly-available data for additional variables that are government-maintained; and I am part of a federally-funded public university. Ironically, my previous blog post about the intersection of science and politics seems to have become even more relevant in the past few weeks.

Many graduate students like me are feeling the crunch as federal agencies close their doors and operations. Most people have seen the headlines that allude to such funding-related issues. However, it’s important to understand what the funding in question is actually doing. Whether we see it or not, the daily operations of the United States Federal government helps science progress on a multitude of levels.

Federal research in the United States is critical. Most governmental branches support research with the most well-known agencies for doing so being the National Science Foundation (NSF), the US Department of Agriculture (USDA), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration. There are 137 executive agencies in the USA (cei.org). On a finer scale, NSF alone receives approximately 40,000 scientific proposals each year (nsf.gov).

If I play a word association game and I am given the word “science”, my response would be “data”. Data—even absence data—informs science. The largest aggregate of metadata with open resources lives in the centralized website, data.gov, which is maintained by the federal government and is no longer accessible and directs you to this message:Here are a few more examples of science that has stopped in its track from lesser-known research entities operated by the federal government:

Currently, the National Weather Service (NWS) is unable to maintain or improve its advanced weather models. Therefore, in addition to those of us who include weather or climate aspects into our research, forecasters are having less and less information on which to base their weather predictions. Prior to the shutdown, scientists were changing the data format of the Global Forecast System (GFS)—the most advanced mathematical, computer-based weather modeling prediction system in the USA. Unfortunately, the GFS currently does not recognize much of the input data it is receiving. A model is only as good as its input data (as I am sure Dawn can tell you), and currently that means the GFS is very limited. Many NWS models are upgraded January-June to prepare for storm season later in the year. Therefore, there are long-term ramifications for the lack of weather research advancement in terms of global health and safety. (https://www.washingtonpost.com/weather/2019/01/07/national-weather-service-is-open-your-forecast-is-worse-because-shutdown/?noredirect=on&utm_term=.5d4c4c3c1f59)

An example of one output from the GFS model. (Source: weather.gov)

The Food and Drug Administration (FDA)—a federal agency of the Department of Health and Human Services—that is responsible for food safety, has reduced inspections. Because domestic meat and poultry are at the highest risk of contamination, their inspections continue, but by staff who are going without pay, according to the agency’s commissioner, Dr. Scott Gottlieb. Produce, dry foods, and other lower-risk consumables are being minimally-inspected, if at all. Active research projects investigating food-borne illness that receive federal funding are at a standstill. Is your stomach doing flips yet? (https://www.nytimes.com/2019/01/09/health/shutdown-fda-food-inspections.html?rref=collection%2Ftimestopic%2FFood%20and%20Drug%20Administration&action=click&contentCollection=timestopics&region=stream&module=stream_unit&version=latest&contentPlacement=2&pgtype=collection)

An FDA field inspector examines imported gingko nuts–a process that is likely not happening during the shutdown. (Source: FDA.gov)

The National Parks Service (NPS) recently made headlines with the post-shutdown acts of vandalism in the iconic Joshua Tree National Park. What you might not know is that the shutdown has also stopped a 40-year study that monitors how streams are recovering from acid rain. Scientists are barred from entering the park and conducting sampling efforts in remote streams of Shenandoah National Park, Virginia. (http://www.sciencemag.org/news/2019/01/us-government-shutdown-starts-take-bite-out-science)

A map of the sampling sites that have been monitored since the 1980s for the Shenandoah Watershed Study and Virginia Trout Stream Sensitivity Study that cannot be accessed because of the shutdown. (Source: swas.evsc.virginia.edu)

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), better known as the “flying telescope” has halted operations, which will require over a week to bring back online upon funding restoration. SOFIA usually soars into the stratosphere as a tool to study the solar system and collect data that ground-based telescopes cannot. (http://theconversation.com/science-gets-shut-down-right-along-with-the-federal-government-109690)

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) flies over the snowy Sierra Nevada mountains while the telescope gathers information. (Source: NASA/ Jim Ross).

It is important to remember that science happens outside of laboratories and field sites; it happens at meetings and conferences where collaborations with other great minds brainstorm and discover the best solutions to challenging questions. The shutdown has stopped most federal travel. The annual American Meteorological Society Meeting and American Astronomical Society meeting were two of the scientific conferences in the USA that attract federal employees and took place during the shutdown. Conferences like these are crucial opportunities with lasting impacts on science. Think of all the impressive science that could have sparked at those meetings. Instead, many sessions were cancelled, and most major agencies had zero representation (https://spacenews.com/ams-2019-overview/). Topics like lidar data applications—which are used in geospatial research, such as what the GEMM Laboratory uses in some its projects, could not be discussed. The cascade effects of the shutdown prove that science is interconnected and without advancement, everyone’s research suffers.

It should be noted, that early-career scientists are thought to be the most negatively impacted by this shutdown because of financial instability and job security—as well as casting a dark cloud on their futures in science: largely unknown if they can support themselves, their families, and their research. (https://eos.org/articles/federal-government-shutdown-stings-scientists-and-science). Graduate students, young professors, and new professionals are all in feeling the pressure. Our lives are based on our research. When the funds that cover our basic research requirements and human needs do not come through as promised, we naturally become stressed.

An adult and a juvenile common bottlenose dolphin, forage along the San Diego coastline in November 2018. (Source: Alexa Kownacki)

So, yes, funding—or the lack thereof—is hurting many of us. Federally-funded individuals are selling possessions to pay for rent, research projects are at a standstill, and people are at greater health and safety risks. But, also, science, with the hope for bettering the world and answering questions and using higher thinking, is going backwards. Every day without progress puts us two days behind. At first glance, you may not think that my research on bottlenose dolphins is imperative to you or that the implications of the shutdown on this project are important. But, consider this: my study aims to quantify contaminants in common bottlenose dolphins that either live in nearshore or offshore waters. Furthermore, I study the short-term and long-term impacts of contaminants and other health markers on dolphin hormone levels. The nearshore common bottlenose dolphin stocks inhabit the highly-populated coastlines that many of us utilize for fishing and recreation. Dolphins are mammals, that respond to stress and environmental hazards, in similar ways to humans. So, those blubber hormone levels and contamination results, might be more connected to your health and livelihood than at first glance. The fact that I cannot download data from ERDDAP, reach my collaborators, or even access my data (that starts in the early 1980s), does impact you. Nearly everyone’s research is connected to each other’s at some level, and that, in turn has lasting impacts on all people—scientists or not. As the shutdown persists, I continue to question how to work through these research hurdles. If anything, it has been a learning experience that I hope will end soon for many reasons—one being: for science.

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

Hypotheses:

Data Description:

Results:

Takeaways to science and management:

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

The questions:

Now, to answer those questions:

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