Seminar: Dr, Dustin Kemp, UAB

UNC Marine Sciences’ Assistant Professor Karl Castillo hosts a seminar presented by Dustin Kemp, Ph.D.

Seminar Title: Modern challenges for coral reefs: Functional traits and genetic diversity of Indo-Pacific and Caribbean coral

Presenter Affiliation: University of Alabama at Birmingham Department of Biology

Summary: Coral reef ecosystems built by photosynthetic corals have endured large fluctuations in temperatures for millions of years, yet, their obligate mutualisms with microalgae (Symbiodinium spp.) are sensitive to environmental perturbation. Flexibility in host-symbiont pairings may help to reconcile this apparent paradox, as symbiont physiological adaptations can determine, in part, how these symbioses rapidly respond to climate change. However, enhanced thermal tolerance is likely aided by the trophic status and unique qualities of each host in which a resilient symbiont resides. Moreover, it is commonly assumed that stress-tolerant symbionts garner large metabolic costs and their role in response to climate change is perceived as negative to the host coral. This paradigm that thermal tolerance comes with metabolic trade-offs may not be ubiquitous. Recent experiments on corals in Palau (West Indo-Pacific) indicate that symbionts within Clade D (S. trenchii) perform well under high temperatures that elicit coral bleaching, and their host corals receive similar amounts of translocated carbon and calcify at rates similar to offshore conspecifics with Clade C Symbiodinium. As seawater warming increases over the next 100 years, increased spread of these symbioses could maintain healthy and productive coral communities. This seminar will discuss the relative importance of acclimatization, adaptation of both partners and shifts in the dominant symbiont, by featuring a series of experiments designed to examine the relative flexibility and functionality of various coral-symbiont pairings exposed to normal and stressful temperatures.