PhD Dissertation Defense: JP Rippe

The PhD Dissertation Defense of John Patrick “JP” Rippe will be presented by the University of North Carolina at Chapel Hill Department of Marine Sciences. The main location of this event will be in seminar room G201 on the ground floor of Murray Hall on UNC main-campus in Chapel Hill, NC. The defense will be streamed live to room 222 of UNC’s Institute of Marine Sciences in Morehead City, NC and online via Zoom (Meeting ID: 199-773-221). This event will be held on Monday, April 8th at 2:00 pm.

Title: Resilience and connectivity of coral reefs at multiple spatial scales throughout the wider Caribbean basin

Abstract: As reports of coral reef decline across the globe continue to mount, it is critical that coastal managers and researchers understand not only the environmental factors that jeopardize coral health, but also the biological and evolutionary forces that strengthen their resilience. Warming oceans are often cited as the most pressing threat to coral reefs, as high temperatures degrade the delicate symbiosis between corals and their single-celled algal partners. This symbiotic breakdown inhibits coral growth and, in severe cases, can lead to widespread mortality. Additionally, rising ocean temperatures have also been shown to significantly increase the virulence and distribution of coral pathogens, which have caused several major coral mortality events throughout the Caribbean region over the past three decades.
Adopting an interdisciplinary approach that incorporates coral skeletal analysis, disease ecology and population genetics, this research explores the physiological resilience of corals in the wider Caribbean basin to these compounding climate threats and evaluates the patterns by which population connectivity may bolster the long-term evolutionary resilience of corals across a cascade of spatial scales. First, we compared the differential response of inner and outer reef corals across the Florida Keys Reef Tract to a major ongoing coral disease outbreak (Chapter 1). Recent research has shown that inner reef corals are better suited to cope with environmental stress due to their exposure to dynamic nearshore conditions, and indeed we found significantly lower disease incidence and mortality at inner reef sites. We then investigated the extent to which this enhanced resilience translates to differences in growth patterns between inner and outer reef corals on the Florida Keys Reef Tract (Chapter 2) and across the western Caribbean basin (Chapter 3) and, in doing so, characterized the environmental drivers behind the observed coral growth trends. Lastly, we explored the genetic structure of a foundational coral species across the wider Caribbean and Gulf of Mexico region to infer a network of population connectivity that may enhance the exchange of adaptive genetic variation throughout the species range (Chapter 4).