Effects of future climate on coral-coral competition

Results Elevated temperature and CO2 significantly changed competitive interactions between M. cavernosa and P. astreoides (Fig 1A, climate x contact, p = 0.027). Under present climate condi- tions, contact with M. cavernosa for 7 days reduced P. astreoides Fv/Fm by 37.5%, but under future temperature and OA, contact reduced Fv/Fm by 100%. For M. cavernosa, direct contact Fig 1. Effects of climate and coral-coral competition on endosymbiont photosynthetic efficiency (Fv/Fm). Maximum quantum yield (means ± SE) for (A) Porites astreoides in contact with Montastraea cavernosa at the location of direct contact (Contact Location) vs. 3 cm away from area of direct contact (No Contact Location) and (B) M. cavernosa in contact with P. astreoides at the Contact Location vs. No Contact Location. Maximum quantum yield values (means ± SE) for (C) P. astreoides in contact with M. cavernosa at points 3 cm away from site of direct contact (No Contact Location) vs. a control P. astreoides fragment not in direct contact with M. cavernosa (No Contact Coral) and (D) M. cavernosa in contact with P. astreoides at points 3 cm away from direct contact (No Contact Location) vs. a control M. cavernosa fragment not in direct contact with P. astreoides (No Contact Coral). Analyses by two-way ANOVA comparing contact and climate for each coral species. Dots show individual data points. The p-value contrasting values between “Contact Location” and “No Contact Location” under future conditions is from one-way ANOVA (N = 6). https://doi.org/10.1371/journal.pone.0235465.g001 PLOS ONE

Climate change alters coral-coral competition PLOS ONE | https://doi.org/10.1371/journal.pone.0235465 August 13, 2020 6 / 16