Category Archives: College of Agricultural Sciences

Is Climate Change Making Gray Whales Picky Eaters?

The Oregon Coast is known for its ruggedness and harsh weather, but also offers a prime opportunity to spot gray whales on their migratory paths. These majestic marine mammals undertake one of the largest migrations of any animal, traveling from the Arctic to Baja California to breed before heading back north along this “whale super-highway.” Despite having the mechanisms to feed in the water column, these benthic specialists prefer bottom feeding, scooping up sand from the seafloor and filtering out invertebrate prey through their baleen, likely targeting locations of high caloric content. However, along the coast of the Pacific Northwest, a behavior known as ‘prey switching’ has been observed, where gray whales feed in the water column instead of their preferred benthic prey, amphipods. Our upcoming guest, Taylor Azizeh, a first-year Ph.D. student at the Marine Mammal Institute, explores what may be driving this prey switching behavior.

Polar regions are among the top locations to be impacted by climate change, which Taylor suspects may be responsible for grey whales switching from benthic to pelagic prey. Changes in bottom water temperature and sediment grain size may result in habitats less favorable for amphipods, leading whales to seek food elsewhere. In response to warming, the distribution of other predators may shift to where they compete for the same food source, or the reduced sea ice cover could result in more productive pelagic waters. How do gray whales, these benthic specialists, adapt to changing food availability?

Gray whale populations often experience boom and bust cycles or unknown mortality events, with the most recent one currently underway. Taylor’s research on the foraging plasticity of gray whales is not only timely, but also employs a holistic approach using a combination of methods to assess the big picture. She plans to use stable isotopes to provide information on what whales are feeding on, but only when combined with GPS tags tracking movement and drone photogrammetry measuring body conditions can one understand where and why. Taylor plans to utilize this combination to ask big picture questions such as whether they’re feeding in areas of high biomass, if they return to those same areas, and how much adaptability can individual gray whales display?

At its core, Taylor’s research delves into the adaptability of gray whales. Gray whales have survived the ice ages, proving their ability to deal with harsh conditions, and Taylor hypothesizes they may be more flexible than we currently understand.

To learn more about Taylor’s passion for these charismatic animals of ecological, social, and cultural importance, the adventure which led here to grad school—from Costa Rica to Ecuador, Denmark, and London—tune in to KBVR 88.7 FM this Sunday, Nov. 3. You can listen to the episode anywhere you listen to your podcasts, including on KBVR, Spotify, Apple, or anywhere else!

Straying from the stream: investigating the impacts of spring Chinook salmon hatchery fish on wild, origin fish

Dams, climate change, habitat loss, predation, anglers. Wild salmon must contend with all of these challenges during some point in their lifetimes. But an additional challenge may be having a negative impact on wild salmon that we don’t yet quite understand: hatchery salmon. The main purpose behind rearing and releasing hatchery salmon into the wild is to increase the number of fish available for anglers (both recreational and commercial) to catch since wild salmon populations are too low in many areas to yield sustainable catches. However, when hatchery fish are released into the wild, some individuals stray. The term straying describes when hatchery fish go where they are not supposed to go. While some degree of straying can be positive because it helps maintain or increase genetic diversity within wild populations, too many hatchery strays could lead to problems for wild salmon. Investigating the impacts of hatchery salmon on wild salmon is no easy feat, and it’s not made easier when you’re trying to do it in possibly one of the most remote and wild places in Oregon…

But that’s exactly what our guest this week is doing! Emily Treadway is a first year Master’s student advised by Dr. Seth White in the Department of Fisheries, Wildlife, and Conservation Sciences at OSU. On top of being a graduate student, Emily is also an employee at the Oregon Department of Fish and Wildlife working within the East Region Fish Research Office. By wearing these two hats and through support from the Lower Snake River Compensation Plan, Emily’s Master’s research aims to do three things: (1) establish baselines for the Wenaha River, (2) determine how a remote region like the Wenaha can be monitored cost-effectively into the future, and (3) hopefully implement certain mitigation efforts or designs that will help support healthy wild salmon populations.

If you want to hear more about Emily’s research, which involves kayaking on the Wenaha, scouting for river hazards, hiking into remote regions with huge solar panel-powered stationary antennas, then tune in to our live show with Emily this Sunday (October 20^th) at 7 pm PST on KBVR 88.7 FM!

If you miss the show, you can check out the interview wherever you get your podcasts, including on our KBVR page, Spotify, Apple Podcasts, or anywhere else!

Sniffing for science

On our last episode for winter term, we interviewed Kayla Fratt, who is currently a PhD student in the Department of Fisheries, Wildlife, and Conservation Sciences. However, aside from being a graduate student, Kayla is also one of the founders and trainers for K9 Conservationists, an organization that unites highly trained conservation detection dog teams with researchers to collect scientific data. For her graduate research, Kayla is working with her canine colleagues, Barley & Niffler, to understand island biogeography effects on diet and movement for sea wolves in southeast Alaska and basic natural history of pumas in El Salvador.

If you’re curious to hear all about how Kayla became a certified dog behavior consultant, how and why in the world you train a dog to sniff out poop, and the plans for Kayla’s PhD dissertation, check out the podcast episode anywhere you listen to podcasts, including on our KBVR page, Spotify or Apple Podcasts!

Poopy predators: Assessing carnivore diet and population dynamics via non-invasive genetics

Getting to the bottom of what top predators in an ecosystem are eating is critical to understand how they may be influencing dynamics in the entire system and food web. But how do you figure out what a predator is eating if it’s hard to catch and collar or watch continuously? Easy, you use their poop! Ellen Dymit, a 4^th year graduate student in the Department of Fisheries, Wildlife, and Conservation Sciences advised by Dr. Taal Levi, is our guest on the show this week and she is a poop-tracker extraordinaire!

For her PhD research, Ellen uses primarily non-invasive genetic methods to study large carnivores in two projects in Alaska and Central America. While the systems and carnivores she studies for these two projects are pretty different, the techniques she uses to analyze the collected scats are the same. The Alaska project is focused on determining what different wolf populations and packs across coastal Alaska are consuming, whether individuals are specialized in their feeding habits, and how large the populations are. The Central America project, which is based out of Guatemala, looks at a whole host of predators, including jaguars, pumas, and ocelots, to gain a better understand of the food web dynamics in the ecosystem.

One of Ellen’s extremely remote field camps in Alaska

Both of these projects involve some unique challenges in the field that Ellen has had to learn to tackle. DNA can deteriorate pretty quickly, especially in warm Guatemalan temperatures, which is problematic when you’re trying to analyze it. Yet, Ellen’s lab has perfected methods over the last few years to work with neotropical samples. Ellen’s Alaska field work is incredibly remote as it’s just Ellen and one field technician roaming the Alaskan tundra in search of wolf scat. Accessing her field sites involves being flown in on a small fixed wing plane, where they are extremely space and weight-limited. Therefore, every single piece of gear needs to be weighed to ensure that the pilot has enough fuel to get to the site and back. As a result, Ellen isn’t able to collect the entire scat samples that she finds but can only take a small, representative sample.

Ellen’s incredibly adventurous field work is followed by months spent in the lab processing her precious scat samples. So far, her results have revealed some pretty interesting differences in diet of wolf packs and populations across three field sites in Alaska. The Guatemalan project, which occurs in collaboration with the Wildlife Conservation Society Guatemala, is one of the first to analyze a large sample size of ocelot scats and the first to attempt DNA metabarcoding of samples collected in the neotropics.

To hear more details about both of these projects, as well as Ellen’s background and some bad-a$$ stories from her Alaskan field work, tune in this Sunday, October 15^th live on 88.7 FM or on the live stream. Missed the show? You can listen to the recorded episode on your preferred podcast platform!

Cheese and disease: how bacteria survive long term

This week we have Andrea Domen, a MS student in Food Science and Technology co-advised by Dr. Joy Waite-Cusic and Dr. Jovana Kovacevic, joining us to discuss her research investigating some mischievous pathogenic microbes. Much like an unwelcome dinner guest, food-bourne pathogens can stick around for far longer than you think. Andrea seeks to uncover the mechanisms that allow for Listeria monocytogenes, a ubiquitous pathogen found in dirt that loves cheese (who doesn’t?), to persist in dairy processing facilities.

Listeria hysteria

Way back in the early 2000s, there were two listeriosis outbreaks that were linked to cheese. Because of these two outbreaks, the British Columbia Centre for Disease Control conducted a sampling program over the course of a decade. From this program, 88 isolates of L. monocytogenes from five different facilities were recovered. Within this set of isolates, 63 were from one facility which is now (perhaps unsurprisingly) shut down. Those 63 microbes were essentially clones of each other, which means this one lineage of microbes seemed to carry something that allowed them to survive for multiple years. So how did that lineage of Listeria survive? Turns out, like a 1990’s Reebok, they pump it. Listeria uses a protein in its cell membrane called an efflux pump to remove harmful chemicals like sanitizers, antibiotics, and heavy metals from the cell. Essentially, when the cell absorbs something that is too spicy – it’ll yeet it back out.

Don’t cry over contaminated milk

The idea that food borne pathogens are evolving to withstand processing environments is alarming, but fret not, the results of Andrea’s research are a first step to avoiding the creation of these super microbes in the first place. Instead, it can serve as a warning story for dairy production facilities about what can happen when L. monocytogenes contamination isn’t properly handled. In healthcare, it’s not uncommon to treat a microbial pathogen with multiple medications – as becoming resistant to several treatments is harder for the microbe than becoming resistant to just one. We are also able to apply this treatment method to sanitizing food production facilities by combining different sanitizers – but that is best left up to the chemists to avoid accidentally making an explosion or lethal gas.

To hear more about how Listeria can survive better than Destiny’s Child be sure to listen live on Sunday, May 7th at 7PM on 88.7FM, or download the podcast.

The opposite of a pest: Bees, wasps and other beneficial bugs

Lots of terrestrial invertebrates have bad reputations. Spiders, bees, flies, wasps, ants. They’re thought of as pests in the garden or they are perceived as threatening, possibly wanting to sting or bite us. I’ll admit it, I’m terrified and grossed out by most invertebrates every time I see one in my house. But this week’s guest may have successfully managed to get me to change my tune…

*Scott (left) and his intern/doppelganger Tucker (right) in the field.*

Scott Mitchell is a 4^th year PhD student in the Department of Fisheries, Wildlife, and Conservation Sciences advised by Dr. Sandy DeBano. His overarching research goal is to understand how different land management practices may impact beneficial invertebrate communities in a variety of managed landscapes. Yes, you read that right: beneficial invertebrates. Because while many invertebrates have a bad rep, they’re actually unsung heroes of the world. They pollinate plants, aerate soil, eat actual pest invertebrates and are prey for many other species. In order to tackle his overarching research goal, Scott is conducting two studies in Oregon; one focuses on native bees while the second looks at non-pollinators such as wasps, spiders, and beetles.

(See captions for images at the end of the blog post)

The first study occurs in the Starkey Experimental Forest and Range which is managed by the US Forest Service. The initial research at Starkey in the 1900s was about how cattle grazing impacts on the land. Since then, many more studies have been undertaken and are ongoing, including about forest management, wildlife, plants, and recreation. For Scott’s study, he is collaborating with the Forest Service to look how bee community composition may differ in a number of experimental treatments that are already ongoing at Starkey. The two treatments that Scott is looking into are thinning (thinned vs unthinned forest) and ungulate density (high vs low). The current hypothesis is that in high ungulate densities, flower booms may be reduced due to high grazing and trampling by many ungulate (specifically elk) individuals, thus reducing the number of available blooms to bees. While in the thinning treatments, Scott is expecting to see more flower blooms available to bees in the thinned sites due to increased access to light and resources because of a reduced tree canopy cover. To accomplish this project, Scott collects bee samples in traps and handnets, as well as data on blooming plants.

(See captions for images at the end of the blog post)

Scott’s second study explores non-pollinator community composition in cherry orchards in the Dalles along the Columbia River Gorge. Agricultural landscapes, such as orchards, are heavily managed to produce and maximize a particular agricultural product. However, growers have options about how they choose to manage their land. So, Scott is working closely with a grower to see how different plants planted underneath orchards can benefit the grower and/or the ecology of the system as a whole.

To hear more details about both of these projects, as well as Scott’s background and several minutes dedicated solely to raving about wasps, tune in this Sunday, April 23^rd live on 88.7 FM or on the live stream. Missed the show? You can listen to the recorded episode on your preferred podcast platform!

Figure captions

Image 1: This bright green native bee is foraging on flowers for nectar and pollen. It is probably in the genus Osmia.

Image 2: A brightly colored bumblebee foraging on a rose.

Image 3: This is one of the most common bumblebee species in western Oregon – the aptly named yellow-faced bumble bee (Bombus vosnesenskii).

Image 4: Most native bees, like this small mining bee are friendly creatures and will even crawl onto your hands or fingers if you let them. No bees (or human fingers) were harmed in the making of this photo.

Image 5: While Scott doesn’t know what his favorite wasp is, this large furry, friendly bee is his favorite native bee species. It is known as the Pacific digger bee or Anthophora pacifica. This is his favorite bee because they are very agile fliers and fun to watch foraging on flowers. They are a solitary species that lives in the ground.

Image 6: Not only are wasps beautiful, but sometimes the signs they leave behind can be too. This is a gall from a gall forming cynipid wasp. Wasp galls are a growth on plants that occurs when a wasp lays its eggs inside of a leaf or other plant structure.

Image 7: This is a pair of wasps in the family Sphecidae. The wasp on top is a male wasp (males are often smaller than females in wasps and bees) and he is likely guarding a potential mate by hanging onto her back.

Image 8: This is a beautiful bright metallic jewel wasp, probably in the family Chrysididae. This wasp was mentioned in the episode.

Image 9: This sphecid wasp is foraging on nectar on flowers. Many insects, including wasps, use nectar as an energy source in their adult life stage – even if they act as predators when foraging for their young.

Image 10: This is a tiny wasp on a flower. This wasp is around 1.5-3 millimeters long.

Nobody wants to eat bitter cheese

There are many adjectives used to describe the taste of different kinds of cheese: mild, tangy, buttery, nutty, sharp, smoky, I could continue but I won’t. Our preferences between these different characteristics will then drive what cheese we look for in stores and buy. But I would wager that most people (or dare I say anyone?) are rarely looking for a bitter cheese. I had never thought about how cheese could be bitter; probably because it’s something that I’ve never tasted before and that’s because the cheese production industry actively works to prevent cheese from being bitter. Intrigued? Good, because our guest this week researches why and how cheese can become bitter.

Paige Benson is a first year Master’s student advised by Dr. David Dallas in the Food Science Department. For her research, Paige is trying to understand how starter cultures affect the bitterness in aged gouda and cheddar cheeses. The cheese-making process begins with ripening milk, during which milk sugar is converted to lactic acid. To ensure that this process isn’t random, cheese makers use starter cultures of bacteria to control the ripening process. The bitterness problems don’t appear until the very end when a cheese is in its aging stage, which can take anywhere from 0-90 days. During this aging process, casein proteins (one of the main proteins in milk and therefore cheese) are being broken down into smaller peptides and it’s during this step that bitterness can arise. Even though this bitter cheese problem has been widely reported for decades (probably centuries), there are many different hypotheses about what causes the bitterness. Some say it might be the concentration of peptides, while others believe it’s a result of the starter culture used, and a third school of thought is that it’s the specific types of peptides. Paige is trying to bring some clarity to this problem by focusing on the bitterness that might be coming from the peptides.

To accomplish this work, Paige will be making lots of mini cheeses from different starter cultures, then aging them and extracting the peptides from the cheese to investigate the peptide profiles through genome sequencing. Scaling down the size of the cheeses will allow Paige to investigate starter cultures in isolation as well as in combination with different strains to see how this may affect peptide profiles, and therefore potentially bitterness.

*Some of the mini cheeses Paige makes for her research*

Besides Paige’s research in cheese, we will also be discussing her background which also features lots of dairy! As a Minnesotan, Paige grew up surrounded by the best of the best dairy. In fact, her grandparents owned and ran a dairy farm, where Paige spent many of her summers and holidays. Her passion for food science was solidified when she started working as an organic farmer during her senior year of high school and she hasn’t ever looked back. Join us on Sunday, April 16^th at 7 pm live on 88.7 FM or on the live stream. Missed the live show? You can listen to the recorded episode on your preferred podcast platform!

Grouper groupie: studying climate change and the Nassau grouper

During winter months, a few days after the full moon, thousands of fish make their way to the warm tropical waters off the west coast of Little Cayman, Cayman Island. Nassau Grouper are typically territorial and don’t interact often, but once per year, they gather in the same spot where they all spawn to carry on the tradition of releasing gametes, in the hopes that some of them will develop to adulthood and carry on the population.

Our guest this week is Janelle Layton, a Masters (and soon to be PhD) student in Dr. Scott Heppel’s lab in the Department of Fisheries, Wildlife, and Conservation Sciences. Janelle’s research focuses on this grouper, which is listed as near threatened under the Endangered Species Act. Overfishing has been the largest threat to Nassau Grouper populations, but another threat looms: warming waters due to climate change. This threat is what Janelle is interested in studying – how does the warming water temperature affect the growth and development of grouper larvae?

Each winter Janelle travels to this aggregation site in the Cayman Islands, where these large groups of grouper (grouper groups?) aggregate for a few days to reproduce. During this time, she collects thousands of fertilized Nassau Grouper eggs to take back to the lab and study. These eggs will develop in varying water temperatures for 6 days, where each day a subset of samples are preserved for future analysis.

So far, Janelle is finding that the larvae raised in higher temperatures tend to demonstrate not only an increase in mortality, but an increase in variability in mortality. What does this mean? Basically, eggs from some females are able to survive and develop under these stressful conditions better than eggs from other females – so is there a genetic component to being able to survive these temperature increases?

The answer may lie in proteins

Aside from development and mortality, Janelle is investigating this theory by measuring the expression of heat shock proteins in the fertilized eggs and larvae. Heat shock proteins are expressed in response to environmental stressors such as increased temperatures, and can be measured through RNA sequencing. The expression of these proteins might hold the key to understanding why some grouper are more likely to survive than others. Janelle’s work is a collaborative effort between Oregon State University, Scripps Institute of Oceanography, Reef Environmental Education Foundation and the Cayman Islands Department of Environment.

To learn more about Nassau Grouper, heat shock proteins, and what it’s like being a Black woman in marine science, tune into Janelle’s episode this upcoming Sunday, March 12th at 7 PM! Be sure to listen live on KBVR 88.7FM, or download the podcast if you missed it. You can also catch Janelle on TikTok or at her website.

Finicky Fish: Investigating the impact of dams on the John Day White Sturgeon

This week we have a Fisheries and Wildlife Master’s student and ODFW employee, Gabriella Brill, joining us to discuss her research investigating the impact of dams on the movement and reproduction habits of the White Sturgeon here in Oregon. Much like humans, these fish can live up to 100 years and can take 25 years to fully mature. But the similarities stop there, as they can also grow up to 10 ft long, haven’t evolved much in 200 million years, and can lay millions of eggs at a time (makes the Duggar family’s 19 Kids and Counting not seem so bad).

Despite being able to lay millions of eggs at a time, the White Sturgeon will only do so if the conditions are right. This fish Goldilocks’ its way through the river systems, looking for a river bed that’s just right. If it doesn’t like what it sees, the fish can just choose not to lay the eggs and will wait for another year. When the fish don’t find places they want to lay their eggs, it can cause drastic changes to the overall population size. This can be a problem for people whose lives are intertwined with these fish: such as fishermen and local Tribal Nations (and graduate students).

The white sturgeon was once a prolific fish in the Columbia River and holds ceremonial significance to local Tribal Nations, however, post-colonialization a fishery was established in 1888 that collapsed the population just four years later in 1892. Due to the long lifespan of these fish, the effects of that fishery are something today’s populations have still not fully recovered from.

Image of white sturgeon in a river. It is a large bluish grey fish. The river is a murkey dark green color. — White Sturgeon

Can you hear me now

Gabriella uses sound transmitters to track the white sturgeon’s movements. Essentially, the fish get a small sound-emitting implant that is picked up by a series of receivers – as long the receivers don’t get washed away by a strong current. By monitoring the fish’s journey through the river systems, she can then determine if the man-made dams are impacting their ability to find a desirable place to lay eggs.

Journey to researching a sturgeon’s journey

Gabriella always gravitated towards ecology due to the ways it blends many different sciences and ideas – and Fish are a great system for studying ecology. She started with studying Salmon in undergrad which eventually led to a position with the ODFW. Working with the ODFW inspired her to get a Master’s degree so that she could gain the necessary experience and credentials to be a more effective advocate for changes in conservation efforts that are being made. One way to get clout in the fish world: study a highly picky fish with a long life cycle. Challenge accepted.

Gabriella Brill holding a smaller sturgeon while on a boat.

To hear more about these finicky fish be sure to listen live on Sunday February 26th at 7PM on 88.7FM, or download the podcast.

A Gut Feeling: Examining Whale Ecology Using Number-Two Genetics

This week we have a MS (but soon to be PhD) student from the department of Fisheries and Wildlife, Charles Nye, joining us to discuss their work examining the dietary and environmental DNA of whales. So that begs the question – how exactly does an environment, or a diet, have DNA? Essentially, the DNA of many organisms can be isolated from samples of ocean water near the whales, or in the case of dietary DNA, can be taken from the whales’ fecal matter – that’s right, there’s a lot more you can get from poop than just an unpleasant smell.

Why should we care about what whales eat?

As the climate changes, so too does the composition of creatures and plants in the oceans. Examining environmental DNA gives Charles information on the nearby ecological community – which in turn gives information about what is available for the whale to eat plus what other creatures they may be in resource competition with. He is working to identify the various environmental DNA present to assist with conservation efforts for the right whale near Cape Cod – a whale that they hold as dear to their hearts on the East Coast as the folks of Depoe Bay hold the grey whale to theirs.

By digging into the whale poop to extract dietary DNA, Charles can look into how the whales’ diets shift over seasonal and yearly intervals – and he is doing precisely that with the West Coast grey whales. These dietary shifts may be important for conservation purposes, and may also be applied to studying behavior. For example, by looking at whether or not there are sex differences in diet and asking the ever-important question: do whales also experience bizarre pregnancy cravings?

two people underwater in scuba gear. Some tall kelp in the background. One person is holding a light which emits a beam into the water. — Scuba diving underwater.

How does someone even get to study whales?

Like many careers, it starts with an identity crisis. Charles originally thought they’d go into scientific illustration, but quickly realized that they didn’t want to turn a hobby he enjoyed into a job with deadlines and dread. A fortunate conversation with his ecology professor during undergrad inspired him to join a research lab studying intertidal species’ genetics – and eventually become a technician at the Monterey Bay Aquarium Research Institute.

After a while, simply doing the experiments was not enough and they wanted to be able to ask his own questions like “does all the algae found in a gray whale’s stomach indicate they may actually be omnivores, unlike their carnivorous whale peers?” (mmm, shrimp).

Turns out, in order to study whales all you have to do is start small – tiny turban snail small.

Image of Charles working in the lab and using a micropipette. They are wearing a lab coat and white rubber gloves. He is holding a small tube into which the tip of the micropette is inserted. — Working in the lab.

Excited for more whale tales? Us too. Be sure to listen live on Sunday, February 5th at 7PM on 88.7FM, or download the podcast if you missed it. Want to stay up to date with the world of whales and art? Follow Charles @thepaintpaddock on Twitter/Instagram for his art or @cnyescienceguy on Twitter for his marine biology musings.

Inspiration Dissemination

Inspiring Stories From Oregon State Graduate Students on 88.7 KBVR FM