Research

Testing Ecological Theories

My research aims to test ecological theories using empirical evidence (data gathered in the field or through modeling). Ecological theories allow us to attempt to understand systems we do not have much data on, which is especially helpful since many large, dynamic systems are difficult to study and we do not have unlimited resources to study every ecosystem on Earth. For example, I've tested the efficacy of riverine theories to the structuring of large, anthropogenic rivers and trophic theory regarding extinction risk of organisms. I use the empirical evidence to determine if theories are accurate or should be updated to better reflect ecosystem structuring. I also apply research results to management and conservation actions for real-world applicability.

Ecosystem-based fisheries management of Lake Erie

Lake Erie is a highly managed and disturbed system with productive percid fisheries. We are evaluating qualitative/semi-quantitative ecosystem conceptual models regarding ecological components' effects on yellow perch, walleye, and lake whitefish in Lake Erie. Check back for more details to see how this project progresses.

Resource use of fish in the Upper Mississippi River System

Quantifying ecological patterns in large rivers is difficult for a variety of reasons, leading to little empirical evidence on how rivers function and how organisms interact with their environments. I am quantifying life-long, seasonal, and daily resource use of twelve native fishes in the Upper Mississippi River system (Mississippi River north of Cairo, IL and the Illinois River) using otolith microchemistry, stable isotopes, and diets. Combined with concurrent studies on vital rates (growth, mortality, and recruitment) and genetics, we aim to determine stock delineation, management needs, and the level of ecosystem functioning in this highly managed but ecologically poorly understood large river.

Streamlining natal origin assignment

Hard part microchemistry analyses are used to assign organisms like fish to a natal origin (birth place). These analyses rely on analyzing the chemical composition of metabolically inert aging structures such as fish otoliths using a mass spectrometer and laser (LA-ICPMS). Resulting data files are clunky and hard to work with, so I have created repeatable R scripts to streamline the data wrangling process. After data processing, organisms are assigned to a natal origin based on the aging structure's chemistry compared to water chemistry. In many instances, origin classifications rely on a lot of collected data that may not be available and are assigned through a long and not easily reproducible process. With the help of collaborators, including Dr. Jimena Golcher-Benavides, we are working to streamline the process of assigning organisms to natal origin by co-opting established tools in other areas of ecology.

Intra and inter individual variation in resource use

Organisms choose their resources based on availability and individual preferences, which leads to phenotypic plasticity or simply put that organisms choose different resource from one another. However, identifying the resources select across their lives is difficult because we cannot reliably recapture individual organisms. Using chronologically and integrated tissues like otoliths and eye lenses of fish, we can compare resource use among individuals and within an individual's lifetime. My former undergraduate mentee, Azareah Carson, used the eye lenses of bowfin and largemouth bass to compare their life-long resource use between and among individuals. The analyses and write-up of this research is ongoing. Highlight: she won an award for best poster presentation on this research at SIUC's student research symposium.

Vertebrate extinction risk

Earth is in the sixth mass extinction, which is the only extinction event caused by humans. Extinctions are generally not random, and it was believed that predatory animals had the highest extinction risk, but no empirical evidence existed for this claim. We quantified the extinction risk of all mammals, birds, and reptiles and found that herbivores from each group consistently had highest extinction risk and extinctions at both global and regional scales.

Lake sturgeon ecology and aquaculture

Lake sturgeon are a long-lived and culturally important species in the Midwest United States. They have much lower population sizes due to overharvest, pollution, and habitat degradation, so conservation efforts have attempted to rebuild their populations as well as understand their ecology to improve management. I was part of the great lakes sturgeon long-term research project through Michigan State University and the Michigan DNR. I conducted a few research projects that involved quantifying growth of reared larvae fed different diets, gut microbiota composition during diet shifts, and predator-prey experiments to understand how predators respond to lake sturgeon and other prey.

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