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James A. Nelson

I am an interdisciplinary scientist most interested in the fish related components of marine ecosystems.  I use a combination of field surveys, experimental approaches, stable isotope analysis, and mathematical modeling to quantify the functional role of marine organisms in mediating energy flow, biogeochemical cycles, and community structure. 

Full C.V. 

Current Lab Members

Jackie Valladares

Lab Manager - Full C.V.

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I received my B.S. in Environmental Biology from the University of Delaware in 2018. Since then I have worked for Americorp as an Invasive Plant Technician, a Naturalist for the Department of Natural Resources and Environmental Regulation at the Aquatic Resources Education Center, and a tutor for students 1st-12th grade.  I am joining the Nelson Lab as a research technician and I am excited to explore some new facets of research including working in the Broussard Assimilation Wetland and helping out on the Ship Shoal project to help me further explore which niches really pique my interests as a scientist.

Email: Jacqueline.Valladares[at]


Alex Thomas

MS Student - Full C.V.


After completing my B.S. in Marine Science from the University of Delaware in 2018, I began working for the State of Delaware as a Wetlands Field Technician. I then worked for Americorp; first as a trail builder in Upstate New York and then as an Oyster Aquaculture Technician on the Eastern Shore of Maryland.  After working for the Nelson Lab as the Assimilation Wetland technician, as of Fall 2022, I have transitioned to a MS student for the Port Fourchon Career project, focusing on mapping the chancing ecosystem using drone imagery. 



Emelie Foster

MS Student - Full C.V.


My research interest primarily focus on understanding how anthropogenic disturbances are affecting coastal populations. During my time here in the Nelson Lab, I plan to use stable isotopes to better understand how trophic systems in the Gulf of Mexico are responding to the alteration of habitat structure, caused by sand dredging. I've recently earned a B.S. in Biology from the University of Louisiana at Lafayette. In the future, I hope to become a part of the link that connects science with the community.

Email: emelie.foster1[at]

Twitter: @FosterEmelie

Olivia Floyd

MS Student - Full C.V.

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I first became associated with the Nelson lab as a summer REU with the Marine Biological Laboratory studying fish ecology and salt marsh food web dynamics at the Plum Island LTER site. I have since earned a B.S. in Environmental Science from Western Washington University and will transition into biogeochemistry for my M.S. I plan to study the impacts of sand dredging on microphytobenthic communities with the BOEM Ship Shoal project. My generalized interests include the economic implications of ecosystem damage and failure for the human industry in addition to the applications of ecosystem science beyond the scope of strictly academic research.

Email: olivia.floyd1[at]

Alexander Douwes

MS Student - Full C.V.


I joined the Nelson lab in August 2021 as a M.S. student at the University of Louisiana at Lafayette with Dr. Roberts and Dr. Nelson as my co-advisors. I earned a BS degree in Marine Sciences with a concentration in Marine Biology from the University of Delaware in 2018. After graduating, I worked at Mote Marine Laboratory as a crustacean ecologist and coral health technician. My Master's research will focus on the changing nutrient fluxes of the Ship Shoal area during and after dredging has occurred.

Email: alexander.douwes1[at]

Herbert Leavitt

PhD Student - Full C.V.


I grew up in the wetlands of south Louisiana and developed an interest in coastal ecology early on. After working for coastal restoration crews nearly every summer of high school, I got my degree in Marine Science and Environmental Studies at Eckerd College in St. Petersburg, FL. My research with the Nelson Lab is focused on understanding how trophic systems respond and adapt to change, particularly how coastal ecosystems respond climate-driven encroachment of mangroves in south Louisiana. I am interested in studying how habitat changes effect far-reaching trophic cascades that impact valuable ecosystem functions. I believe that a better understanding of cross-habitat energy flow and trophic connections will be a crucial part of managing Louisiana’s resources to best address the environmental challenges of the coming century.



Jess Courson

MS Student - Full C.V.


I first joined the lab as an undergraduate assistant and quickly became the go-to person for helping with fieldwork. I have since graduated with a BS in chemistry and joined the Nelson lab as a MS student. I will use my time at the Nelson lab to study the freshwater habitats of microbes that reduce methane emissions. Specifically, my project will explore how insect bioirrigation influences oxygen availability in sediments, and the rate of methane removal. Methane removal due to insect activity may be an overlooked sink of the greenhouse gas. I am passionate about the adaptive mechanisms of wetland ecosystems and excited to be part of a lab that regularly deepens my appreciation for the web of life.

Email: Jessica.Courson1[at]

Former Lab Members 
Graduate Students

Skyler Flaska, M.S.

Justin Lesser, PhD

Post-doc at University of Vermont


Mason Harris, M.S.

Environmental Scientist, Wetland & Stream Restoration


David Behringer, M.S.

North Carolina WRC

W. Ryan James, PhD

Post-doc at FIU

Undergraduate Students

Laura McDonald


Tori Furka


Jada Wilson


Emma Weiser

Staff Members

Kristen Fellows, M.S.

Former Lab Manager

Currently a Research Investigator with DuPont

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