In partial fulfillment of the requirements for the degree of

Doctor of Philosophy in Ocean Science & Engineering
In the
School of Earth and Atmospheric Sciences

Luisa Fernanda Lopera Garcia

Will defend her dissertation

CONNECTIVITY AMONG MESOPHOTIC CORAL ECOSYSTEMS IN THE NORTHERN GULF OF MEXICO AND THE ROLE OF SUBMESOSCALE CIRCULATIONS

29TH May 2026
2:00 pm EST
Ford ES&T 3235 – The ocean room
https://gatech.zoom.us/j/92021737062

Thesis Advisor:
Annalisa Bracco, Ph.D
CMCC Foundation
School of Earth and Atmospheric Sciences
Georgia Institute of Technology

Committee Members:
Joseph Montoya, Ph.D.
School of Biological Sciences
Georgia Institute of Technology

Takamitsu Ito, Ph.D.
School of Earth and Atmospheric Sciences
Georgia Institute of Technology

Kevin Haas, Ph.D.
School of Civil and Environmental Engineering
Georgia Institute of Technology

Santiago Herrera, Ph.D.
Department of Biological Sciences
Lehigh University
ABSTRACT:

Connectivity, defined as the exchange of genetic material among geographically separated ecosystems, is a key process for maintaining biodiversity and supporting reef resilience. Understanding connectivity patterns is crucial for marine planning, particularly in the design of marine protected areas and restoration plans. This thesis investigates how ocean circulation, model resolution, and biological traits influence potential connectivity among mesophotic coral ecosystems in the northern Gulf of Mexico. Using high-resolution ocean simulations coupled with a Lagrangian particle tracking tool, this work evaluates passive and biologically informed dispersal across multiple seasons and years. Results show that connectivity among mesophotic reef environments is generally weak, even among geographically close sites, but episodic shelf-break transport can create intermittent pathways between otherwise isolated reefs. Connectivity magnitude is enhanced during winter and spring, while directionality is strongly affected by intraseasonal variability. This thesis also shows that passive-particle simulations alone can misrepresent ecological connectivity, as species-specific traits such as vertical migration and pelagic larval duration substantially modify transport pathways. Preliminary resolution-sensitivity experiments suggest that sub-kilometer simulations reveal additional weak or episodic connections, although the dominant connectivity patterns remain broadly similar to those captured at 1 km. Overall, this work demonstrates that reliable connectivity assessments require both biologically informed particle-tracking experiments and ocean models capable of representing the physical processes that shape transport in complex shelf-break environments.