Category Archives: Ecology

Zebrafish sentinels: studying the effects of cadmium on biology and behavior

Cadmium exposure is on the rise

There’s a good chance you might have touched cadmium today. A heavy metal semi-conductor used in industrial manufacturing, cadmium is found in batteries and in some types of solar panels. Fertilizers and soil also contain cadmium because it is present in small levels in the Earth’s crust. The amount of cadmium in the environment is increasing because of improper disposal of cell phone batteries, contaminating groundwater and soil. This is a problem that impacts people all over the world, particularly in developing countries.

Plants take up cadmium from the soil, which is how exposure through food can occur. Leafy greens like spinach and lettuce can contain high levels of cadmium. From the soil, cadmium can leach into groundwater, contaminating the water supply. Cadmium is also found in a variety of other foods, including chocolate, grains and shellfish, as well as drinking water.

Cadmium has a long half-life, reaching decades, which means that any cadmium you are exposed to will persist in your body for a long time. Once in the body, cadmium ends up in the eyes or can displace minerals with similar chemical properties, such as zinc, copper, iron, and calcium. Displacement can cause grave effects related to the metabolism of those minerals. Cadmium accumulation in the eyes is linked to age-related macular degeneration, and for people in the military and children, elevated cadmium is linked to psychosocial and neurological disorders.

Read more about cadmium in the food supply:

Cadmium in chocolate: https://thechocolatejournalist.com/cadmium-chocolate/

Chocolate cadmium economic debate: https://www.ictsd.org/bridges-news/bridges/news/eu-regulation-on-cadmium-in-chocolate-fuels-wto-debate-on-health

Cadmium – Chocolate California: https://www.confectionerynews.com/Article/2018/03/08/California-Superior-Court-settles-heavy-metal-chocolate-lawsuit

Using zebrafish to study the effects of cadmium

Delia Shelton, a National Science Foundation post-doctoral fellow in the Department of Environmental and Molecular Toxicology, uses zebrafish to investigate how cadmium exposure in an individual affects the behavior of the group. Exposing a few individuals to cadmium changes how the group interacts and modifies their response to novel stimuli and environmental landmarks, such as plants. For example, poor vision in a leader might lead a group closer to predators, resulting in the group being more vulnerable to predation.

Zebrafish

As part of her post-doctoral research, Delia is asking questions about animal behavior in groups: how does a zebrafish become a leader, how do sick zebrafish influence group behavior, and what are the traits of individuals occupying different social roles? These specific questions are born from larger inquiries about what factors lead to individual animals wielding inordinately large influence on a group’s social dynamic. Can we engineer groups that are resilient to anthropogenic influences on the environment and climate change?

Zebrafish

Zebrafish are commonly used in biomedical research because they share greater than 75% similarity with the human genome. Because zebrafish are closely related to humans, we can learn about human biology by studying biological processes in zebrafish. Zebrafish act as a monitoring system for studying the effects of compounds and pollution on development. It is possible to manipulate their vision, olfactory system, level of gene expression, size, and aggression level to study the effects of pollutants, drugs, or diseases. As an added benefit, zebrafish are small and adapt easily to lab conditions. Interestingly, zebrafish are transparent, so they are great for imaging. Zebrafish have the phenomenal ability to regenerate their fins, heart and brain. What has Delia found? Zebrafish exposed to cadmium are bolder and tend to be attracted more to novel stimuli, and they have heightened aggression.

Read more about zebrafish:

ZFIN- Zebrafish Information Network – https://zfin.org/

Zebrafish International Research Center in Eugene Or – http://zebrafish.org/home/guide.php

What led Delia to study cadmium toxicity in zebrafish?

As a child, Delia was fascinated by animals and wanted to understand why they do the things they do. As an undergrad, she enjoyed research and pursued internships at Merck pharmaceutical, a zoo consortium, and Indiana University where she worked with Siamese fighting fish. She became intrigued by social behavior, social roles, and leadership. Delia studied the effects of cadmium in grad school at Indiana University, and decided to delve into this area of research further.

Delia began her post-doctoral work after she finished her PhD in 2016. She was awarded an NSF Postdoctoral Fellowship to complete a tri-institute collaboration: Oregon State University, Leibniz Institute for Freshwater Ecology and Inland Fisheries in Berlin, Germany, and University of Windsor in Windsor, Ontario. She selected the advisors she wanted to work with by visiting labs and interviewing past students. She wanted to find advisors she would work well with and who would help her to accomplish her goals. Delia also outlined specific goals heading into her post-doc about what she wanted to accomplish: publish papers, identify collaborators, expand her funding portfolio, learn about research institutes, and figure out if she wanted to stay in academia.

Research commercialization and future endeavors

During her time at OSU, Delia developed a novel assay to screen multiple aspects of vision, and saw an opportunity to explore commercialization of the assay. She was awarded a grant through the NSF Innovation Corps and has worked closely with OSU Accelerator to pursue commercialization of her assay. Delia is now wrapping up her post-doc, and in the fall, she will begin a tenure track faculty position at University of Tennessee in the Department of Psychology, where she will be directing her lab, Environmental Psychology Innovation Center (E.P.I.C) and teaching! She is actively recruiting graduate students, postdocs, and other ethnusiatic individuals to join her at EPIC.

Please join us tonight as we speak with Delia about her research and navigation of the transition from PhD student to post-doc and onwards to faculty. We will be talking to her about her experience applying for the NSF Postdoctoral Fellowship, how she selected the labs she wanted to join as a post-doc, and her experience working and traveling in India to collect zebrafish samples.

Tune in to KBVR Corvallis 88.7 FM or stream the show live on Sunday, April 7th at 7 PM. You can also listen to the episode on our podcast.

Stream ecosystems and a changing climate

Examining the effect of climate change on stream ecosystems

Oak Creek near McDonald Dunn research lab. The salamander and trout in the experiments were collected along this stretch of creek.

As a first year Master’s student in the lab of Ivan Arismendi, Francisco Pickens studies how the changing, warming climate impacts animals inhabiting stream ecosystems. A major component of stream ecosystem health is rainfall. In examining and predicting the effects of climate change on rainfall, it is important to consider not only the amount of rainfall, but also the timing of rainfall. Although a stream may receive a consistent amount of rain, the duration of the rainy season is projected to shrink, leading to higher flows earlier in the year and a shift in the timing of the lowest water depth. Currently, low flow and peak summer temperature are separated by time. With the shortening and early arrival of the rainy season, it is more likely that low flow and peak summer temperature will coincide.

A curious trout in one of the experimental tanks.

Francisco is trying to determine how the convergence of these two events will impact the animals inhabiting streams. This is an important question because the animals found in streams are ectothermic, meaning that they rely on their surrounding environment to regulate their body temperature. Synchronization of the peak summer temperature with the lowest level of water flow could raise the temperature of the water, profoundly impacting the physiology of the animals living in these streams.

How to study animals in stream ecosystems?

Salamander in its terrestrial stage.

Using a simulated stream environment in a controlled lab setting, Francisco studies how temperature and low water depth impact the physiology and behavior of two abundant stream species – cutthroat trout and the pacific giant salamander. Francisco controls the water temperature and depth, with depth serving as a proxy for stream water level.

Blood glucose level serves as the experimental readout for assessing physiological stress because elevated blood glucose is an indicator of stress. Francisco also studies the animals’ behavior in response to changing conditions. Increased speed, distance traveled, and aggressiveness are all indicators of stress. Francisco analyzes their behavior by tracking their movement through video. Manual frame-by-frame video analysis is time consuming for a single researcher, but lends itself well to automation by computer. Francisco is in the process of implementing a computer vision-based tool to track the animals’ movement automatically.

The crew that assisted in helping collect the animals: From left to right: Chris Flora (undergraduate), Lauren Zatkos (Master’s student), Ivan Arismendi (PI).

Why OSU?

Originally from a small town in Washington state, Francisco grew up in a logging community near the woods. He knew he wanted to pursue a career involving wild animals and fishing, with the opportunity to work outside. Francisco came to OSU’s Department of Fisheries and Wildlife for his undergraduate studies. As an undergrad, Francisco had the opportunity to explore research through the NSF REU program while working on a project related to algae in the lab of Brooke Penaluna. After he finishes his Master’s degree at OSU, Francisco would like to continue working as a data scientist in a federal or state agency.

Tune in on Sunday, June 24th at 7pm PST on KBVR Corvallis 88.7 FM, or listen live at kbvr.com/listen. Also, check us out on Apple Podcasts!

A very Hungry Caterpillar, a very Tenacious Scientist

Tyria jacobaeae (cinnabar moth) caterpillars chowing down on Senecio triangularis at Marys Peak summer 2014

Tyria jacobaeae (cinnabar moth) adult Photographer: Eric Coombs

Our guest this week is Madison Rodman who recently finished her Master’s degree in Botany and Plant Pathology. Growing up as the daughter of crime lab scientist and an ecologist in North Dakota, Madison told us that there was not a singular moment when she knew she wanted to do science; she always loved the outdoors. It is no surprise that Madison is a go-getter and a very organized scientist herself, but her science story is less than typical. Madison’s first research experience involved hiking through the jungles of Thailand surveying for tigers! While wildly adventurous, this trip taught Madison that field work is not all rainbows and tiger stripes, but that there are venomous snakes in the jungle and tigers are good at hiding. What drew Madison to this field trip was the opportunity to see the organism in its habitat, but she also realized that all the lovely jungle plants were hiding in plain sight and waiting to be surveyed as well.

Madison Rodman poses with her research organism Senecio triangularis summer 2016

Upon returning to Minneapolis to continue her undergraduate studies at the University of Minnesota, Madison focused on Plant Biology and realized that plant-insect interactions were something that interested her. She applied for a Research Experience for Undergraduates (REU) at the University of Michigan, and spent the summer investigating the impact of atmospheric CO₂ levels on plant chemistry and how changes in leaf defense chemistry affects herbivores. This was the pièce de résistance of a science project combining: whole organism science, plant-insect interactions, and climate change biology. Things were really coming together for Madison, and she knew she wanted to go on to graduate school and continue studying plant-insect interactions.

Manipulative experiment in action near Big Lake summer 2015

She did just that, and much much more, at Oregon State. Madison defended her Master’s thesis this winter, through which she studied the risk of a biocontrol agent, the cinnabar moth, on a native plant, Senecio triangularis, or arrow-leaf groundsel. These biocontrol caterpillars, will chomp the European tansy ragwort, an invasive weed, to the ground and look pretty cute doing it, but in some parts of Oregon they have recently switched to feeding on the native arrow-leaf groundsel. The good news: the tansy buffet is in low supply; the bad news: arrow-leaf groundsel is on the menu. How risky is the annual feeding of cinnabar moth caterpillars on arrow-leaf groundsel populations? Can caterpillar feeding have negative effects on the reproduction and survival of arrow-leaf groundsel? Both the arrow-leaf groundsel and the cinnabar moth are here to stay, but this native plant might be in trouble as annual temperatures continue to rise. You’ll have to tune in to hear more about the cinnabar moth and Madison’s field work in the high Cascades and Coast Range of Oregon. We promise it is all rainbows and moths…

Madison in her native habitat near Mount Hood summer 2016

Also at Oregon State, Madison has also been able to practice and boost her teaching skills through the Graduate Certificate in College and University Teaching (GCCUT) program. She has always loved communicating science, from being an undergraduate teaching assistant at U of MN to intern at Wind Cave National Park. Madison hopes to stay involved in teaching and community outreach after grad school when she relocates to Minnesota. We’re so excited to present her perspective on graduate school and share her science story.

Tune in to KBVR Corvallis 88.7FM this Sunday February, 5 at 7 pm PST to hear Madison’s story and learn about plant-insect interactions. You will not want to miss her take on graduate school, biocontrol, and beyond.

Not a local listener? Don’t fret, you can stream this episode live at www.kbvr.com/listen.

Inspiration Dissemination is happy to announce its addition to the KBVR archive as a podcast! Listen to this episode whenever and where ever you have internet access. Link TBA.

Birds to bacteria and kickstarting research boundaries

Did you know us humans have a background army of microbes that work to keep us healthy, turns out these microbial cells outnumber human cells 10 to 1 in a healthy human body! The human microbiome is beginning to be elucidated that shows most of these microbes have a mutualist relationship such as helping us to digest food or producing anti-inflammatories that our human genome can’t produce. Similar to humans, other mammals are expected to have a similar microbiomes that can contribute to a healthy species. However this area of research is in it’s infancy, our guest is spearheading this effort and pushing the boundaries of avian-microbe interactions in tropical environments that can help us understand what contributes to a healthy bird population.

Felipe after sampling a baby trogon (Trogon melanocephalus). This species only nest inside termite nests.

Felipe found his way to these avian-microbe questions while pursing a masters degree at a Chamela biological field station in Mexico. He noticed that some young birds he found in termite-associated nests were dirty and grimy, but they were very healthy! How could this be? His curiosity continued to drive his motivation to pursue a PhD in the Biology Department at the University of Oregon. Yes that’s right he’s a duck, but science holds no grudges because all that really matters is what kind of knowledge this research can produce.

His passion for the outdoors started young while growing up visiting small towns in the seasonal dry jungles of Mexico. He recalls playing with his siblings but would always stop and look at cool rocks, or to show his friends all the creepy crawly insects he found! Only recently did he discover his siblings thought this was annoying because he was more focused on observing his surroundings than playing games with them; sound like a scientist in the making!

Felipe is teaching two field assistants (Rosi and Jesus) how to take body measurements of chicks.

He is now in his 5th year of his project but has run into a sort of barrier; his research interests are the boundaries of where other researchers have ventured. If he is successful he will be one of few who will assess how nesting behavior influence bird-biomes in a tropical setting. Pushing boundaries may sound glamours but it comes at a cost, literally, because few agencies are willing to fund such a new exploration he’s chosen to pursue other means of obtaining funding.

Experiment.com is a way of combining a grant submission easily understandable to the public, and they can fund your work similar to a kickstarter. As Bill Gates said, “This solution helps close the gap for potential and promising, but unfunded projects.” Felipe’s campaign to raise enough money to help process 500 samples collected from the Mexican jungles has just started and will continue until the end of November. You can learn more about his project on his Facebook page. If you’re interested in this ‘crowd-sourced’ version of research funding you can read about how the process works.

Flycatcher chick after being sampled and measured.

You’ll have to tune in to hear the current state of his research as well as how this new funding venture could provide him the avenue to finish his PhD! You can listen October 30th 2016 at 7PM on the radio at 88.7FM KBVR Corvallis, or stream live.

Mosquito soup in the Brazilian rainforest

Fieldwork in the Brazilian Amazonia meant continuously trying to outsmart their savviest opponents…ants!

Deforestation in Brazil due to cultivation of monoculture crops, such as soybean, has profoundly impacted wildlife populations. In the lab of Taal Levi in the Department of Fisheries and Wildlife, wildlife biologist Aimee Massey has adopted a quantitative approach to studying this impact. During her first and second year of graduate school, Aimee traveled to Brazil for fieldwork and data collection, collaborating with researchers from Brazil and the UK. During this trip, she collected 70,000 biting flies, including mosquitoes and sandflies, by engineering 200 fly traps constructed from 2-liter soda bottles, netting, and rotting beef. Aimee installed biting traps throughout 40 individual forest patches, which are regions delineated by their physical characteristics, ranging approximately in size from the OSU campus to the state of Rhode Island.

Who knew fieldwork could be such a balancing act?!…especially when trying to avoid poisonous insects and thorns. Let’s hope the next branch Aimee reaches for is not of the slithering snake kind!

Subsequent DNA analysis on biting flies provides a relatively unbiased source of wildlife tracking, since mosquitoes serve as a repository of DNA for the wildlife they have feasted upon. DNA analysis also provides information regarding diseases that may be present in a particular patch, based on the bacterial and viral profile. For example, sandflies are carriers of protozoa such as leishmania, which cause the disease leishmaniasis. To analyze DNA, Aimee uses bioinformatics and metabarcoding, which is a technique for assessing biodiversity from an environmental sample containing DNA. Different species of animals possess characteristic DNA sequences that can be compared to a known sequence in an online database. By elucidating the source of the DNA, it is possible to determine the type of wildlife that predominates in a specific patch, and whether that animal may be found preferentially in patches featuring deforestation or pristine, primary rain forest.

Learning about human/wildlife interactions while drinking tea with camel’s milk in Laikipia, Kenya.

Aimee completed her undergraduate studies at University of Maine, where she quickly discovered she wanted to study biology and chemistry in greater depth. She planned to attend med school, and was even accepted to a school in her junior year; however, an introductory fieldwork course in Panama spent exploring, doing fieldwork, and trekking made a deep impression on her, so she decided to apply to graduate school instead. Aimee completed a Masters degree in environmental studies at the University of Michigan, during which time she spent 4 months at the Mpala Research Centre in the middle of the Kenyan plateau, just north of the Masai Mara. Following completion of her Masters degree, Aimee spent a year as a research assistant at the University of New Hampshire working with small mammals. Before beginning her PhD studies at OSU, Aimee spent two months in Haines, Alaska doing fieldwork with her future PI, Taal Levi. After she finishes her PhD, Aimee plans to focus on conservation work in New England where she is originally from.

Having fun after fieldwork; Aimee’s eulachon fish catch of the day in Haines, Alaska. One is better than none!

Tune in on October 23rd, 2016 at 7PM on the radio at 88.7FM KBVR, or stream live, to hear more about Aimee’s adventures in Brazil, and why her graduate work is shaping our understanding of how deforestation impacts biodiversity.

Are You Listening? For Whale’s Sake, Keep it Down!

Our guest tomorrow night, Selene Fregosi PhD student in Fisheries and Wildlife, investigates noises produced by marine mammals and in particular, whales. Selene employs an under water microphone to record the bioacoustics produced by marine mammals over large spatial and temporal scales. Attached to remote controlled marine gliders, these microphones can record bioacoustics of marine mammals, some of which produce sounds of inaudible frequencies. Marine gliders limit the time and expense of whale monitoring from the deck of a marine vessel. This cost effective alternative allows Selene to collect oceanographic measurements like temperature and salinity and her audio recordings remotely through satellite transmitted programing. Selene’s explorations through her project will provide information about the effectiveness of this technology for future research with marine mammals.

Selene getting the glider ready with the help of Alex Turpin.

In addition to the practical aspects of this research, Selene is interested in how noise pollution from ships, submarines, and other vessels affects the behavior of charismatic mega fauna. By examining the sound spectra of an audio recording, Selene can identify each species by their characteristic sound patterns. After deciphering bioacoustics obtained from the microphoned-gliders, Selene can understand whale behavior during different times of year or different locations around the world. In fact, some of Selene’s recordings are the first ever to record whale behavior and movement off the coast of Guam!

Characteristic sound pattern of a beaked whale.

Selene hopes that in the future, her work will aid the conservation of whales and other marine mammals. Deciphering bioacoustics can allow for the identification of when and where specific species are breeding, and conservationists can then work to reduce noise pollution. As our oceans become noisier from human activities, Selene’s research could provide accurate and specific information to limit disruption of crucial population maintenance and growth.

Learn more about Selene’s and other interesting research from the Klinck lab at OSU by visiting their blog.

Join us Sunday, November 22 at 7 pm to hear more about Selene’s research and her unique journey to graduate school. Tune in to KBVR Corvallis 88.7 FM or stream the show live!