Fig. 5: Growth and thermal tolerance of corals from LB and DB lineages based on analysis of individual coral cores distinguished by habitat region.

Outer reef (OR) and Rock Island (RI). In a–c, line segments denote statistically significant differences (p < 0.05) between groups based on post hoc Tukey tests. An asterisk over a single group denotes that group is different (p < 0.05) from all others. a Boxplots of mean skeletal density of samples from each lineage and region. The DB lineage in the outer reefs shows higher density than all other groups (ANOVA, F = 9.212, df = 3, p < 0.001). DB density in RI habitats is significantly lower than in the ORs (1.05 vs. 1.298 g cm⁻³; Post hoc Tukey p < 0.001). Density in LB corals does not differ among habitats. However, they are lower than the DB outer reef coral density in both habitats (p < 0.05). b Boxplots of mean calcification rate of each lineage. There are significant differences among lineages and habitats (ANOVA, F = 5.498, df = 3, p < 0.01). The DB lineage shows significantly lower calcification in the Rock Island habitats compared to the ORs (1.35 vs. 0.82 g cm⁻² year⁻¹; Post hoc Tukey p < 0.01). DB corals in the ORs also have significantly higher calcification than LB corals in the RI (p = 0.04). LB corals in the ORs also have higher calcification than DB corals in the RI (p = 0.04). c Boxplots of mean extension rate of samples from each lineage. ANOVA showed significant differences among lineage and habitats (F = 3.229, df = 3, p = 0.03), but there were no significant pairwise differences in the post hoc test (difference between outer reef LB and Rock Island DB was marginal, p = 0.053). d Stress band prevalence by lineage in 1998. The DB lineage shows a trend toward lower stress band prevalence in the RI habitats (X² = 0.34, df = 1, p = 0.56). The LB lineage does not show any significant difference in stress band prevalence (X² = 0, df = 1, p = 1).