Fig 1.
Temperature profile over the course of the experiment in the four treatments (dark grey = ambient; light grey = ambient+MHW; coral = future; dark red = future+MHW).
Dots indicate the different timepoints (t) where various measurements were conducted (for further details see specific sections). Horizontal bars indicate different experimental phases (pre-impact t0–t4, impact t4–t6 and recovery period t6–t8).
Fig 2.
Standardised photosynthetic efficiency (Fv/Fm) of Corallina/Arthrocardia “robust”, Corallina complex 1, Corallina complex 2 and Phymatolithopsis complex during the impact (a) and the recovery (b) phase in the different treatments. Points show individual values. Solid line indicates the median, box shows the interquartile range (IQR) and the whiskers are 1.5×IQR. Colours indicate treatments (dark-grey = ambient [16°C]; light-grey = amb.+MHW [16°C+2.7°C at t5], coral = future [18.7°C], dark-red = fut.+MHW [18.7°C+2.7°C at t5]). “Pre”, “imp” and “rec” denotes the three experimental phases (pre-impact, impact and recovery). Note: standardisation was achieved by subtraction of the respective Fv/Fm values from the pre-impact phase. Thus, 0 = no change, <0 = lower efficiency and >0 = higher efficiency.
Fig 3.
Maximum relative electron transport (rETRmax) in Corallina/Arthrocardia “robust”, Corallina complex 1, Corallina complex 2 and Phymatolithopsis complex before the impact phase (t4) (a), immediately after the impact phase (t6) (b) and at the end of the recovery phase at t8 (c). Points show individual values. Solid line indicates the median, box shows the interquartile range (IQR) and the whiskers are 1.5×IQR. Colours indicate treatments (dark-grey = ambient [16°C]; light-grey = amb.+MHW [16°C+2.7°C at t5], coral = future [18.7°C], dark-red = fut.+MHW [18.7°C+2.7°C at t5]). “Pre”, “imp” and “rec” denotes the three experimental phases (pre-impact, impact and recovery).
Fig 4.
Chlorophyll a (a), phycocyanin (b) and phycoerythrin (c) content in Corallina/Arthrocardia “robust”, Corallina complex 1, Corallina complex 2 and Phymatolithopsis complex during the impact phase (t5). Points show individual values. Solid line indicates the median, box shows the interquartile range (IQR) and the whiskers are 1.5×IQR. Colours indicate treatments (dark-grey = ambient [16°C]; light-grey = amb.+MHW [16°C+2.7°C at t5], coral = future [18.7°C], dark-red = fut.+MHW [18.7°C+2.7°C at t5]). “Pre”, “imp” and “rec” denotes the three experimental phases (pre-impact, impact and recovery).
Fig 5.
Standardised calcification rates (mgCaCO3 cm-2 d-1) of Corallina/Arthrocardia “robust”, Corallina complex 1, Corallina complex 2 and Phymatolithopsis complex during the impact (a) and the recovery (b) phase in the different treatments. Points show individual values. Solid line indicates the median, box shows the interquartile range (IQR) and the whiskers are 1.5×IQR. Colours indicate treatments (dark-grey = ambient [16°C]; light-grey = amb.+MHW [16°C+2.7°C at t5], coral = future [18.7°C], dark-red = fut.+MHW [18.7°C+2.7°C at t5]). “Pre”, “imp” and “rec” denotes the three experimental phases (pre-impact, impact and recovery). Note: standardisation was achieved by subtraction of the respective calcification rates from the pre-impact phase. Thus, 0 = no change, <0 = slower calcification and >0 = faster calcification.
Fig 6.
Skeletal magnesium content (a) and residual FWHM (proxy for ΩCF) (b) of Corallina/Arthrocardia “robust”, Corallina complex 1, Corallina complex 2 and Phymatolithopsis complex during the impact phase at t5. Points show individual values. Solid line indicates the median, box shows the interquartile range (IQR) and the whiskers are 1.5×IQR. Colours indicate treatments (dark-grey = ambient [16°C]; light-grey = amb.+MHW [16°C+2.7°C at t5], coral = future [18.7°C], dark-red = fut.+MHW [18.7°C+2.7°C at t5]). “Pre”, “imp” and “rec” denotes the three experimental phases (pre-impact, impact and recovery).