No apparent trade-offs associated with heat tolerance in a reef-building coral

Liam Lachs*, Adriana Humanes, Daniel R. Pygas, John C. Bythell, Peter J. Mumby, Renata Ferrari, Will F. Figueira, Elizabeth Beauchamp, Holly K. East, Alasdair J. Edwards, Yimnang Golbuu, Helios M. Martinez, Brigitte Sommer, Eveline van der Steeg, James R. Guest

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
14 Downloads (Pure)


As marine species adapt to climate change, their heat tolerance will likely be under strong selection. Yet trade-offs between heat tolerance and other life history traits could compromise natural adaptation or assisted evolution. This is particularly important for ecosystem engineers, such as reef-building corals, which support biodiversity yet are vulnerable to heatwave-induced mass bleaching and mortality. Here, we exposed 70 colonies of the reef-building coral Acropora digitifera to a long-term marine heatwave emulation experiment. We tested for trade-offs between heat tolerance and three traits measured from the colonies in situ – colony growth, fecundity, and symbiont community composition. Despite observing remarkable within-population variability in heat tolerance, all colonies were dominated by Cladocopium C40 symbionts. We found no evidence for trade-offs between heat tolerance and fecundity or growth. Contrary to expectations, positive associations emerged with growth, such that faster-growing colonies tended to bleach and die at higher levels of heat stress. Collectively, our results suggest that these corals exist on an energetic continuum where some high-performing individuals excel across multiple traits. Within populations, trade-offs between heat tolerance and growth or fecundity may not be major barriers to natural adaptation or the success of assisted evolution interventions.
Original languageEnglish
Article number400
JournalCommunications Biology
Issue number1
Publication statusPublished - 12 Apr 2023

Cite this