Heritable variation and lack of tradeoffs suggest adaptive capacity in Acropora cervicornis despite negative synergism under climate change scenarios

Knowledge of multi-stressor interactions and the potential for trade-offs among tolerance traits is essential for developing intervention strategies for the conservation and restoration of reef ecosystems in a changing climate. Thermal extremes and acidification are two major co-occurring stresses predicted to limit the recovery of vital Caribbean reef-building corals. Here we conducted an aquaria-based experiment to quantify the effects of increased water temperatures and pCO2 individually and in concert on 12 genotypes of the endangered branching coral, Acropora cervicornis, currently being reared and outplanted for large-scale coral restoration. Quantification of 11 host, symbiont, and holobiont traits throughout the 2-month long experiment showed several synergistic negative effects, where the combined stress treatment often caused greater reduction in physiological function than the individual stressors alone. However, we found significant genetic variation for most traits and posi...