Abstract: 

Ocean warming and acidification are challenging the tolerance limits of scleractinian corals. However, beneficial acclimation and stress-hardening via phenotypic plasticity may be pathways to buffer some negative phenotypic effects and improve thermal tolerance. In my thesis, I explored and experimentally tested the response of different life stages of the coral Acropora loripes to two different levels of combined temperature and pCO2 predicted for this century. The assessment included a range of phenotypic traits evaluated on the coral host and associated symbionts (Symbiodiniaceae and bacteria). I found strong evidence for beneficial acclimation and hardening of photosynthetic efficiency, but not in coral growth rate. Photosynthetic efficiency declined in climate change conditions, but was restored in juvenile and adult fragments that had previously experienced climate change conditions. Furthermore, prior exposure to climate change conditions induced thermal hardening that enhanced tolerance to extreme temperatures in both juveniles and adult fragments.. Coral host, rather than experimental treatment, explained the majority of variation in the community structure of symbionts. My thesis highlights both the potential and limitations of the acclimatory response of corals facing climate change conditions under laboratory conditions, and provides insights for its potential applicability to enhance future reef model projections and restoration strategies.

Biography:

Jose was born in Rio de Janeiro – Brazil but grew up in Quito – Ecuador. He finished his B.Sc. in Biotechnology Engineering (Hns) in Ecuador in 2013 in collaboration with the University of Florida (i.e., hybridization occurring in endemic trees in the Andes region). He then decided to take a new challenge in Marine Science, which brought him to Townsville. For his M.Sc. (2014-2016) Jose worked on a molecular protocol to target ssRNA viruses infecting Symbiodiniaceae), under the supervision of Prof. Madeleine van Oppen, Dr. Karen Weynberg and Prof. Bette Willis. He started his Ph.D. with AIMS and the Centre of Excellence for Coral Reef studies in 2016, working under the supervision of Dr. Line Bay, Prof. Madeleine van Open, Prof. Philip Munday and Dr. Nicole Webster.