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Dr. Rosanna J. Milligan


Rosanna (Zan) Milligan is an Assistant Professor in the Dept. of Marine and Environmental Sciences, Halmos College of Natural Sciences & Oceanography at Nova Southeastern University, Florida where she currently leads the Seascape Ecology Lab. She received her PhD in 2015 from the University of Glasgow, UK.

My research interests lie in understanding how the distributions and biodiversity patterns of deep-sea animals are shaped by their environment across multiple spatiotemporal and organisational scales. My lab has a strong focus on data analysis, and we use a variety of statistical and data-driven analytical approaches to better understand dynamic spatial distributions and diversity patterns in deep-sea animals and their driving processes in open ocean and deep-sea ecosystems. I am particularly interested in the role that mobile fauna (particularly fishes) may play in connecting spatially and temporally disconnected ecosystems. As we gain a better understanding of the "natural" drivers of change within these ecosystems, we will be better able to understand and predict the effects of increasing human impacts at all ocean depths. ​

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My ResearcherID: J-3058-2014

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Current Students


Sidney Trimble: Grad. Student Research Associate

Sidney R. Trimble (Current M.S. Marine Science student, Nova Southeastern University; B.S. Biology, Kentucky Christian University, Grayson, Ky) 


Abbie Kerr

BS in Biology from University of Tennessee at Chattanooga


Meta Hughes

Meta Hughes (Current M.S. Marine Science student, Nova Southeastern University, B.S. Biology, University of Texas)

I am currently a Master of Marine Science Student at Nova Southeastern University (NSU) studying fishes in the Seascape Ecology Lab under Dr. Rosanna Milligan. My thesis work focuses on the distribution of fishes in relation to varying light levels in the northern pelagic Gulf of Mexico (GOM). Daytime light levels will be calculated using a light attenuation model that utilizes satellite PAR measurements and will be extrapolated down to 1000m, while nighttime light levels will use moon phase as a proxy. Fish data will come from the data collected during the DEEPEND project. The main goal of this study is to see if fish distribution correlates with varying light intensity. 


Nathan Andrews

Lab Alumni & Former Staff

Ian Areford: Grad. Student Research Associate


I am currently a Master of Science student at Nova Southeastern University (NSU) studying the spatial distributions of deep-sea fishes in the Seascape Ecology Lab under Dr. Rosanna Milligan. My thesis project is focused on analyzing mesopelagic fish biomass patterns in the northern Gulf of Mexico in response to major oceanographic features such as the Loop Current, mesoscale eddies, and freshwater runoff from the Mississippi River. The overall goal is to determine whether these oceanographic features significantly affect the horizontal and/or vertical biomass distributions of these fishes in the northern Gulf of Mexico. 

Ryan Byrne

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Ryan Byrne (Current M.S. Marine Science student, Nova Southeastern University, B.S. Marine Science, University of South Carolina)

I am currently a second year Masters of Marine Science student at Nova Southeastern University (NSU) under Dr. Rosanna Milligan. I am interested in using image-based analyses to help in determining where myctophid specimens may fall in their clade. My thesis project aims to utilize digital image analyses to offer insight into where an unidentified Diaphus specimen may fall within the genus. This is to be done with an examination of the lateral and orbital photophores of various myctophid specimens (mainly Diaphus spp.). Prior to NSU I received my Bachelor of Science in Marine Science at the University of South Carolina.  


Mikayla Twiss (Current M.S. Marine Science student, Nova Southeastern University,

B.S. Marine Biology and Captive Wildlife Care and Education, Unity College)


The overall aim of my current research is to broaden our understanding of fish morphology by relating body shapes with established traits (e.g., vertical distribution patterns and diel vertical migration behaviors) using computer-aided morphometric techniques.


Krista N. Scheuerman (B.S. Southwestern College, Winfield, Kansas, M.S. Marine Biology, Nova Southeastern University)

Graduated: Summer 2022

My research involves analyzing data from the DEEPEND Project, specifically looking at fish biodiversity and  community structure in the deep Gulf of Mexico. I am interested in the diversity of species that were collected in deep water trawls and the distribution of those specimens involving a depth gradient and time of day. The data gathered focused on the previously unknown and generally unstudied mesopelagic fishes of the northern Gulf. I am currently in my first year at Nova Southeastern University and beginning the framework for my thesis research with Dr. Milligan in the Seascape Ecology Lab. 

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Adam Warren (M.S. Marine Biology, Nova Southeastern University)

Graduated: Summer 2022

My current research involves examining the patterns of diel and ontogenetic vertical migration, vertical abundance, and distribution in the mesopelagic lanternfish in the northern Gulf of Mexico through detailing their size structuring and life history. My thesis aims to get a better understanding of one of the dominant fish in the highly complex and variable ecosystem structure of the Gulf of Mexico.

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Thomas Ingalls (B.S Marine Biology, M.S. Marine Biology, Nova Southeastern University)

Graduated: Winter 2021

I am interested in age and growth of commercial sciaenids from the Gulf of Mexico. My thesis focuses on how the shape and structure of otoliths change with age and environment. I will be using a combination of image analyses and increment analysis to study how the morphology of otoliths change with age, and if we can use shape and structure as a novel predictor of age.

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Nina Pruzinsky: Research Assistant (Oct 2020-Feb 2022)

M.S. Marine Biology, Nova Southeastern University, B.S. Environmental Science, University of Delaware

Nina’s Masters thesis focused on the identification, faunal composition, and spatiotemporal distributions of larval and juvenile tunas in the northern Gulf of Mexico. The findings from the spatiotemporal distribution analyses are highlighted in her recent publication entitled, “Pelagic habitat partitioning of late-larval and juvenile tunas in the oceanic Gulf of Mexico,” in Frontiers in Marine Science (doi: 103389/fmars.202000257). In Dr. Milligan’s lab, Nina conducts statistical analyses on biological and environmental data collected during the NRDA ONSAP and DEEPEND cruises in the Gulf of Mexico. Her recent research interests have focused on analyzing vertical distributions of deep-pelagic fishes on fine-scale depth ranges and differing solar cycles. She has also worked on identifying life history traits that can be used to create functional groups of deep-sea fishes for ecosystem management purposes. 

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