Author Archives: Xitlali Ramirez

Interviewing Jonathan Behrens, PhD candidate

Jonathan Behrens, or Jonny, is my graduate student mentor at the Bernhardt Lab. This summer, he’s taught me valuable field work methods and skills. I was excited to learn that he spent 3.5 years as a community organizer when he was an undergraduate. As a fellow organizer, I was thrilled to find somebody else who’s had experience in organizing and wants to use that knowledge to help make science accessible and people-serving. He says he enjoyed the critical thinking skills that organizing requires. Additionally, it helped him build connections with the community and understand his own passions.

Jonny majored in chemistry and minored in environmental studies at UChicago. He worked at a laboratory during his time as an undergraduate, but he didn’t think about pursuing a PhD after graduating. Instead, he worked for a science policy thinktank for the federal government. As Jonny worked, he realized that systemic issues couldn’t be fixed overnight. He wanted to combine his interests in chemistry, environmental science, and community organizing to learn how contaminants get into waterways and find methods to meaningfully address these issues.

Jonny searched for researchers that were answering the questions he was interested in. That is how he met Emily Bernhardt, the lab’s PI. They hit it off well and Jonny became a new member of the Bernhardt lab, where we are now working together! In the future, Jonny says he wouldn’t mind being a professor, but he would prefer being a scientist working for the federal government to help inform policy.

Overall, Jonny is a grounded, results-driven scientist who wants to use his research to address systemic issues such as climate change and environmental degradation.

 

 

Urban Stream Ecology: Watershed development negatively impacts aquatic insect diversity and ecosystem health in urban rivers

Author: Xitlali Ramirez

Mentors: Jonathan Behrens, Emily Bernhardt, PhD

Department of Biology

Impervious surfaces in urban development dramatically increase river discharge and contaminant presence in urban rivers, thereby creating a turbulent environment for aquatic insects and the river ecosystem. Durham’s Ellerbe Creek (EC) and New Hope Creek (NHC) watersheds vary significantly in urbanization, with EC being % developed and NHC being 7.9% developed, however the effects of this urbanization on aquatic insects and river ecosystem health have yet to be measured in Durham. I hypothesize that overall aquatic insect biodiversity and the abundance of pollution-sensitive orders will be lower at EC than at NHC.  I calculate the biodiversity and abundance of aquatic insects at two EC sites and one NHC site using sticky traps and make a qualitative water quality assessment. I compare that data to precipitation and discharge data collected by the USGS and our sensors.  EC’s Glenn Stone site has the highest aquatic insect abundance among the three sites. However, NHC’s site shows more diversity and more resilient species among the sites, suggesting that pollution is highly likely at EC and highly unlikely at NHC. Further quantitative assessments of water quality and river ecosystem health at these sites are needed to inform urban river conservation in Durham.

Microbiomes in pitcher plants!

This week, I enjoyed listening to everyone as they presented and communicated their projects. One chalk talk that caught my interest was delivered by Ali and is titled “life in a pitcher.” This talk was about carnivorous pitcher plants and their relationship with the microorganisms that live in the water that accumulates in the plants. These organisms often take a bite out of the animals that land in the pitcher plant, but to my understanding they leave some leftovers for the plant. The plant also secretes digestive enzymes to help break down the animals. I was specifically intrigued by one of Ali’s research questions. I believe it was along the lines of “how does a pitcher plant’s latitudinal placement affect its enzyme secretion? The hypothesis is that the higher the latitude, the more energy the plants would have to conserve to stay alive. This makes sense because there is less sunlight available in higher latitudes compared to lower or mid-latitudes. Therefore, pitcher plants may decrease or completely stop secreting digestive enzymes to conserve energy. This would increase their dependency on microorganisms to break food down, even if those organisms take some food for themselves. 

 

I personally find this intriguing because the study of microbiomes and their relationships with the host is an exciting, emerging field. I think that it may be true that higher latitude pitcher plants may secrete less enzymes to conserve energy, but I wonder if having microorganisms that take some of their food is actually beneficial for them or if it’s a nuisance. Perhaps they prefer to conserve energy at higher latitudes by some other means and instead secrete more digestive enzymes. Perhaps the presence of these microorganisms is negligible for pitcher plants. Whatever the case is, I think it’s a very interesting topic to look into as it increases our understanding of microbiome-host relations. 

My exciting life in the field was interrupted by surgery

My daily life in the lab took quite the untraditional turn when I developed lower abdominal pain on Tuesday, May 25th. It started off as a pain that was barely there–it didn’t restrict my movement at all. I was able to make it to the BSURF faculty talk, learn about mating signals, and then talk to friends on the bus without noticing much pain. However, the pain became more intense right as I was about to sit down and read some papers for my lab.

On any regular weekday before this pain started, I would’ve sat down to read papers and practice learning how to use R studio for 2-3 hours. Then, I would’ve met with my graduate student mentor Jonny Bherens and a senior lab assistant to go out and do field work. Much of our work involved taking samples of aquatic insects at different levels of the river ecosystem. First, we’d take samples at the riverbed, then we’d set emergence traps right above the water, and finally we’d set up sticky traps in the branches. We did this for all of our river sites. We even went out to collect the spiders that eat these insects. On one of these spider-catching trips, we canoed up the Flat River, stopped about a hundred meters below the dam, and collected our specimens throughout a 60 meter area along the river channel. This work is perfect for me and I loved every second of it. Here are a few pictures from my field work:

Emergence traps at Ellerbe Creek

Hard at work: Me setting a stake in Ellerbe Creek! 🙂

A beautiful picture of the Flat River from my canoe

Unfortunately, May 25th was not a regular weekday. I tried my best to focus on the paper I was reading, but my pain got in the way. I wanted to believe it was something to do with needing to go to the bathroom, but that didn’t help at all. The time came for my regularly-scheduled field work and I wanted to tough it out because I love being in the field and I wanted to make the most out of my time. That’s why I decided to ignore my stomach pain and walk to the River Center to meet Jonny.

To make a long story short, the pain didn’t subside, so Jonny took me back to my dorm to rest. It wouldn’t go away no matter what I tried, so I went to the ER at 1 AM and had an emergency surgery. I could barely walk for a few days, but now I walk well on stable, horizontal surfaces. I missed out on almost two weeks worth of research which makes me feel overwhelmed when I think about catching up. However, I’m looking forward to presenting an awesome chalk talk despite my setbacks.

As for how my daily life in the lab will look like, I will not be able to do field work for the remainder of my research. This is pretty sad but I’m still excited knowing that I’ll be able to do field work again in the fall! From now on, I’ll either be in the lab or working from home and focusing on walking better each day.

I’m not bugging around!

I was never a fan of insects and spiders, but sometimes you have to face your fears for the sake of science. This summer, I’m working with the Bernhardt Lab to help gather data for our Bass Connections project: ‘A City and Its River: Durham’s Ellerbe Creek Watershed.’ This project combines the fields of chemistry, biology, and social science to seek to understand if/how wealth and social status affect the state of the environment for Durham’s Ellerbe Creek watershed residents. So you may be asking, where do the bugs come in?

I’m working alongside a graduate student to look at 3 river sites in Durham. The developed Northgate and Glen Stone sites are in Ellerbe Creek and our third site, also known as our reference site, is New Hope Creek in the Duke forest. We’re using different techniques to catch samples of fly larvae within the water, right above the water, and then far above the water. I will be taking the sticky traps that we use to catch flies far above the water and using them to measure weekly biodiversity and abundance across all three sites. Then, I will use physical data such as stream temperature, precipitation, storm surges, etc. to see if they have any correlation with biodiversity and abundance. Basically, my general aim is to see why biodiversity and abundance differs across all three sites. I hypothesize that urban stream sites will see lower biodiversity due to storm surges and higher temperatures, but this is yet to be seen. My work will involve counting and identifying insects on the sticky traps each week. I’m not particularly fond of bugs, but I am fond of my research question, so I just have to pull through!

My Field Frog

This week, I virtually met everyone I’m working with at the Bernhardt Lab, AKA Duke’s Aquaterrestrial Biogeochemistry Lab! It’s quite a mouthful. and a bit overwhelming to hear at first, but so far I’m enjoying the lab. At the lab’s weekly zoom meetings, everyone is encouraged to state their “weekly frog.” This frog is a weekly goal that we set for ourselves in front of everyone so we can be held accountable for these goals for at the next meeting. I enjoyed hearing the impressive goals that people set for themselves–I’m bad at remembering names however one wonderful person is collecting data to see how the United States’ rivers have changed temperature since the 1950s. I have the opportunity of taking thermal images of rivers! I’m very excited to learn about all the different field methods and techniques that environmental science has to offer 🙂

My weekly frog is to be in the field as much as possible and learn everything I can about my work. So far I’ve been in the field twice and I loved it! My project involves sampling aquatic and terrestrial bugs at three different river sites in Durham to see what the differences in biodiversity are between each site. We are currently focusing on fly larvae. We will use our knowledge of which Orders of flies are sensitive to pollution and our data to show the quality of each site. Then, we will grind the bugs up to see if there is any bioaccumulation of contaminants in their food webs. I’m excited to go into the field and learn more about the work I’m doing.

I’m specifically excited about working with the Bernhardt lab this summer because I will also be working with them in the following fall and spring through Bass Connections. Coming into this project early will allow me to get the hang of the work quickly so I can have more time to explore my interests. All in all, I’m grateful for the for the opportunity of working in the Bernhardt Lab and I look forward to what this summer has to offer.