Defense Date

12-5-2022

Document Type

Thesis

Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

Timothy Swain, Ph.D.

Second Advisor

Robert Smith, Ph.D.

Third Advisor

Joana Figueiredo, Ph.D.

Abstract

Increasing global ocean temperatures and frequency of marine heatwaves pose dire consequences for coral reefs. High temperatures often lead to disruptions in coral symbiosis resulting in coral bleaching, increasing the mortality of corals. However, corals can potentially avoid bleaching peril by associating with thermally tolerant symbionts. Here we provide a tool for understanding symbiosis network stability of Caribbean reef-building corals. We created a network of Caribbean hermatypic corals and their associated Symbiodiniaceae phylotypes. A bleaching model was applied to this network to test for resilience and robustness (R50) to thermal stress. It was also layered with trait data for coral life history strategy, conservation attention and population status, as well as network measures including betweenness and eigenvector centrality. We found that the Caribbean network exhibits a narrow window in which it can resist bleaching but that it remains relatively robust to thermal stress. We identified one coral, Dichocoenia stokesii, to be heat tolerant, network-critical, and in need of conservation attention. Additionally, we found potential evidence of phylogenetic inertia exhibited by Madracis decactis as well as evidence for high connectance of invasive Symbiodiniaceae phylotypes, D1 and D1-4, amongst Caribbean hermatypic corals. The latter of which poses potential for a trade-off in biological function for increased thermotolerance. The resilient, network stabilizing corals identified in this study should be the focus of continued restoration effort in the Caribbean. It is vital to future-proof Caribbean reefs to protect the economic, cultural, and biological value they provide.

ORCID ID

0000-0002-8654-0782

CaribNetwork_R Files.zip (118 kB)
R files and data associated with analysis

CaribNetwork_Supplemental D1.docx (15 kB)
CTAB Extraction Protocol

CaribNetwork_Supplemental T1.xlsx (761 kB)
Association Records

CaribNetwork_Supplemental T2.xlsx (24 kB)
Master List with Coral Traits

Share

COinS