Our next guest is Matt Vaughan, a third year PhD student in Integrative Biology working with Prof. Sarah Henkel in the Benthic Ecology Lab. Matt originally hails from Melbourne, Australia and recently joined the ID team as a host. A major theme of his research interest is biological “disturbance and change”, meaning the impact of stressors on organisms and ecosystems.

Matt’s PhD research centers around invertebrate life found on the ocean floor, known to researchers as the “Benthic zone”. He focuses especially on ghost shrimp, a type of crustacean that builds burrows on the ocean floor. In the Pacific Northwest, ghost shrimp have historically inhabited estuaries, the areas where rivers flow into the sea. Within the last decade however, a significant population of ghost shrimp has arisen much farther than expected for the species, more than seven miles off the coast of Oregon and southern Washington. This mysterious colonization could have been spurred by environmental disruptions such as climate change, and the shrimp also represent a significant change in the local ecology of the ocean floor. Firstly, ghost shrimp burrows alter the habitat for preexisting invertebrate species, reducing stability on the seafloor. The large and intricate burrows are often in high densities, and the sand they kick up through their bioturbation can affect the survival and behavior of invertebrates like bivalves. Ghost shrimp burrows also oxygenate the sediment and host vibrant microbial communities, together altering the biogeochemistry of the ocean floor.

Matt studies these ecological dynamics by surveying the ocean floor during boat trips out of Newport. His team samples the bed using box cores to collect, identify and count the invertebrates. Matt then uses computational and statistical analysis to characterize the population structure of these areas, particularly seeking to tease out the differences in species distribution between areas with and without ghost shrimp burrows. Ghost shrimp are also relatively large compared to other invertebrates in the area, so their arrival provides a significant potential food source for larger marine life like sturgeon and even gray whales. In the rest of his PhD, Matt hopes to model this trophic impact in the long term.

To hear more about Matt’s research and how his travels to the Great Barrier Reef and Southeast Asia helped him discover his love for science, tune into KBVR 88.7 tonight at 7pm or listen soon after wherever you get your podcasts.

Trophic ecology studies how energy flows through food webs; basically who is eating whom in an ecosystem. Understanding the structure of feeding relationships among species in a system helps us to understand why populations may fluctuate in terms of abundance or distribution at different times. These dynamics are particularly important to consider in the face of a changing climate as conditions like increasing temperatures make resources less predictable. Our guest this week is Luke Bobay, who is trying to do exactly this for anchovy in the Pacific Ocean off the US West Coast.

Luke, a 3^rd year PhD student in Integrative Biology, is researching the potential influences of climate change on anchovy abundance by studying its ecological effects on their early life stages. Anchovy are forage fish, which means they are eaten (aka foraged upon) by a lot of larger animals such as birds, marine mammals, other predatory fish, and humans. They are also short-lived and therefore we expect their population dynamics to respond pretty quickly to things that are happening in the environment.

For his research, Luke is looking at the larval stage of anchovy. He uses samples and plankton imagery data collected on weeks-long research cruises that Plankton Ecology Lab has conducted during the past six years, as well as samples collected by the National Oceanic and Atmospheric Administration (NOAA) since 1996. The samples that Luke uses are collected using large nets with a very fine mesh that enables the collection of tiny plankton. The imagery data are collected using a sampling technology unique to Luke’s lab called the In Situ Ichthyoplankton Imaging System (ISIIS). ISIIS uses a high-resolution camera to take images of the water column at a very high spatial and temporal scale, allowing the lab to basically take one long continuous image of what’s happening in the top 100 m of the ocean. These images are then run through an AI image classification model that automatically identifies and measures each individual plankter that is recorded. Both the net and the ISIIS also record data about the environment, such as temperature, salinity, and depth. By examining relationships between environmental conditions, the abundance of other plankton, and the abundance and other characteristics of anchovy larvae, Luke explores the factors that may contribute to variability in anchovy abundance.

In Situ Ichthyoplankton Imaging System (ISIIS)

To hear more about the day in the life of an anchovy, as well as Luke’s journey from OSU to another OSU, tune in this Sunday, November 5^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!

Northern anchovy (credit: Monterey Bay Aquarium)

We have a special guest this week on Inspiration Dissemination, our own Dr. Grace Deitzler (she/they) who is graduating this term with a PhD in Microbiology! Grace was on an episode of ID earlier in her degree and has served as a host since 2021. In this episode, we will mostly cover the remainder of Grace’s PhD work and give them a send-off both from OSU and from ID.

In the early part of her PhD, Grace worked on mice models of autism and examined the effects of bacterial infection on autism-like behaviors. Since then, her research has focused on a much different species – honeybees. A connective thread between these two disparate phases of research is the “double-hit hypothesis”. This refers to the idea that two concurrent stressors on an organism can increase vulnerability to or severity of disease, beyond the impact of either stressor individually. In mice, the two stressors were a simulated maternal infection during gestation and a subsequent infection of the offspring. In honeybees, the double-hit of interest to Grace is treatment with probiotics after an infection, in this case by a microsporidian fungus.

In comparison with mice or humans, honeybees have a very homogeneous microbiome, with just 8-10 bacterial species accounting for around 95% of the total. The minimalism of the honeybee microbiome and its conservation across individuals suggests that the insect and its bacteria have co-evolved for millions of years. As pollinators, honeybees are of vast ecological and economic importance, with $20 billion in agricultural activity sustained by managed colonies in the US. Beekeepers are understandably interested in protecting their colonies from infection by pathogens such as fungi and foreign bacteria. Much like the probiotic shakes marketed for human consumption, companies have developed probiotic products for honeybees and marketed them towards keepers.

Grace’s research findings cast this practice into doubt. They exposed the pupae to Nosema, a common fungal pathogen that targets the bees’ gut. Then they treated some bees with probiotics. Somewhat counterintuitively, infected individuals treated with probiotics died more quickly than those not fed probiotics! Premature death due to probiotic administration was even observed among healthy bees not exposed to the pathogen. This surprising result spurred Grace to investigate possible mechanisms for probiotic-induced mortality. The Nosema infection damages the bee’s microbiome, eliminating many species from the gut. Grace found that although the probiotic partially restores some of these bacterial species, it leads to more subtle disequilibria in the microbiome at the level of specific bacterial strains. She hypothesizes that this imbalance induces stress that is enough to worsen the bee’s ability to survive. Their results also raise questions about the efficacy of current honeybee probiotics, which appear to do more harm than good. After final analyses are complete, these results will be available in a forthcoming paper.

To hear more about the details of bees and bacteria as well as Grace’s experiences in science communication, tune in this Sunday, June 11^th, at 7PM on 88.7 KBVR. 

This week’s guest is Alexander Butcher, a second-year master’s student in the Department of Crop and Soil Science. Alexander has a wide variety of interests related to minimizing food waste and improving global food security, but his current research focuses on protecting potato crops from insect pests.

Typical chemical pesticides are effective deterrents against invading insects but can cause significant harm to the environment and to humans. Such substances can present health risks to the farm workers that apply the pesticides as well as the consumers who purchase and eat the treated crops. Runoff from agriculture can also cause damage to surrounding ecosystems. In light of these downsides, scientists are interested in finding safer alternatives to conventional pesticides. Alexander studies an alternative class of chemicals called elicitors, which act as signals to activate defense mechanisms of plants. Plants have evolved numerous chemical and structural defenses for fending off insect and microbial attackers as well as competing against other plant species. One such product of this evolutionary arms race is the caffeine that you might enjoy in your morning cup of coffee. Elicitors can selectively turn these defenses on or off. This gives farmers and plant breeders a lot more possibilities for using plant defenses to manage insects.

Alexander’s research focuses on potatoes, which are an important agricultural product in northeastern Oregon along the Washington border. One of the biggest insect pests of potato is the Colorado potato beetle. Alexander is testing strategies for using two synthetic chemical analogs of natural plant signal hormones– salicylic acid and jasmonic acid — to stimulate the natural defenses of potato plants. Jasmonic acid is a phytohormone that promotes defenses against insects that chew, like the Colorado potato beetle. Some of Alexander’s research shows that these defenses can lower the weight of beetles. He thinks that this is due to protease inhibitors, which disrupt the enzymes insects use to digest proteins. Similarly, salicylic acid plays a major signaling role in plant development and defenses against insects that pierce into the plant and suck out fluids, like aphids. While these natural products have the potential to serve as affordable and effective pesticides, their sublethal effects lag behind the efficacy of more lethal chemicals. To help close this gap, Alexander has been researching how potato defenses induced by elicitors can impact the behavior of the beetle and its ability to reproduce.

Alexander first came to an interest in agriculture through his passion for food. He was classically trained in French cuisine and worked as a chef for twelve years, where he experienced first-hand the amount of waste that happens in the food system. His travels in countries affected by food insecurity helped solidify a desire to return to school, and he attended Portland State for a degree in biology. Despite his day job defending crops from insect invaders, he maintains a significant interest in bugs, founding an entomology club at Oregon State. Alexander will be transitioning into the PhD degree in the fall and switching topics towards defending vineyards from vine mealybugs. He eventually hopes to pursue a career in academic research and education.

To hear more about Alexander’s story, including why he advocates for insects as a sustainable protein source, tune in this Sunday, May 28th, at 7PM on KBVR 88.7 FM.