Current: University of Maine

At the University of Maine, I am pursuing a PhD in Ecology and Environmental Science and am studying sedimentary DNA (sedDNA), which is DNA that has been shed by an organism into the environment and has since been preserved in the sediment record. Specifically, I hope to detect fish and zooplankton sedDNA to help understand historic species distributions and community shifts over time.

Sedimentary DNA is a relatively new and emerging field of environmental DNA that looks to isolate and amplify target DNA preserved in sediment, which can persist for thousands of years. This research can be species specific and can be used to determine a species presence/absence through time, or it can be applied to whole communities to help researchers better understand the biodiversity at a specific point in time.

Fish sedDNA Review (In Progress)
Detecting fish DNA from lake sediments has been more challenging than detecting other aquatic taxa, such as plants or microbes. Additionally, the taphonomy of fish environmental DNA is poorly understood, which limits the ability to effectively sample for and interpret data. Together with research teams in Europe, Japan, Australia and New Zealand, we are writing a comprehensive review of factors, processes, and methodological uncertainties surrounding fish sedimentary DNA, along with workflows to overcome potential challenges encountered from sample collection to data interpretation.

Spatial Variation in Fish sedDNA Concentration (In Progress)
I hope to understand how fish DNA concentrations vary spatially in lake surface sediments across different depths and habitats, investigate whether fish sedDNA variability is associated with habitat-specific shedding or degradation rates, and determine the optimal sampling location to detect historic fish sedimentary DNA.

Alewife (Alosa pseudoharengus) Presence/Absence (In Progress)
Alewife are a culturally, ecologically, and economically important species to the state of Maine that has undergone drastic population declines in the last century. I hope to correlate the presence/absence of alewife DNA found in a sediment column to known historical records of this species distribution. My goal is to implement sedDNA as a reliable survey tool for researchers and conservationists to use to determine the historic presence/absence and distribution of target species, in the absence of known historical records.

Sedimentary DNA Community Analysis (Upcoming)
Along with the alewife-specific research, I hope to use sedDNA to broaden my understanding of historical fish and zooplankton communities, and understand how they shifted due to the removal or reintroduction of an influential species such as alewife. Using Next-Generation Sequencing (DNA metabarcoding), DNA found in sediment samples will be compared to a database of known species to determine which species are present in any given sample. A better understanding of how historic communities responded to change will help contemporary researchers predict how current or future communities will shift due to various pressures such as climate change or the introduction of an invasive species. Additionally, sedDNA can allow us to understand how communities and general biodiversity have changed over the years.