Do high heat resistant corals have lower recovery rates from bleaching


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


33-8  Sat Jan 2  Do high heat resistant corals have lower recovery rates from bleaching? Walker, NS*; Palumbi, SR; Stanford University, Hopkins Marine Station; Stanford University, Hopkins Marine Station niasw@stanford.edu

Global coral bleaching has focused attention on interventions to increase heat resistance. However, a key feature of climate resilience is the ability to recover from bleaching—as well as resist it. Here, we tested individual Acropora hyacinthus colonies’ heat resistance and recovery capabilities. We subjected 27 colonies, found in Palau, to acute heat stress until they moderately bleached (~50% symbiont reduction). These colonies were then split into low, moderate, and high resistance categories based on number of days to bleach and transferred back to the reef via a common garden. We measured recoverability on the order of weeks to 4 months post-heat stress. As expected, mortality was highest among low resistant colonies (60%) and lowest in high resistant colonies (30%). However, our current data show a dramatic result: after experiencing the same level of bleaching, moderately resistant corals grew the fastest. Moderately resistant corals grew 4 times faster than the highest and lowest resistant corals. The best future corals may have moderate resistance and higher recoverability. These results suggest that high heat resistance may come along with a tradeoff in growth potential that changes how reefs are viewed and managed. It may be critical to better understand resilience to improve long-term conservation initiatives.

the Society for
Integrative &
Comparative
Biology