Date of Award

Spring 5-2023

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Ocean Science and Engineering

Committee Chair

Dr. Xiaodong Zhang

Committee Chair School

Ocean Science and Engineering

Committee Member 2

Dr. Kristina Mojica

Committee Member 2 School

Ocean Science and Engineering

Committee Member 3

Dr. Christopher Hayes

Committee Member 3 School

Ocean Science and Engineering


The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different for distinct groups, largely differentiated by external membrane (Diatoms, Coccolithophores, Dinoflagellates, and Ciliates). Additionally, differences between species were seen in the volume portions of different structures, further necessitating the use of different bulk RIs for different species of phytoplankton. The bulk RI for diatoms shows strong agreement with previous data, validating this method as a way to directly measure the RI of phytoplankton moving forward.



Included in

Oceanography Commons