Figure 5
From: Giant clam (Tridacna) distribution in the Gulf of Oman in relation to past and future climate
Long-term environmental variability. (a) Differences in the δ18O and δ13C signatures of T-Tiwi1 and T-Fins. Arrows indicate the directions of isotope ratio changes with increasing temperature/precipitation and upwelling strength. (b) Variations and trends in annual mean, maximum and minimum sea surface temperature (SST). (1, 2) Recent annual SST variability at Tiwi based on (1) a long-term (2003–2019) satellite-based daily SST dataset (Supplementary Fig. S3) and (2) monthly averages of the daily SST data. MIS3 stadial and interstadial SSTs were calculated from δ18Oshell values using the equations for T. maxima41 (Eq. 1) and giant clams41 (Eq. 2). The horizontal blue solid line marks the lower temperature threshold for coral reefs46 and the horizontal blue dashed lines indicate the lower temperature threshold interval for non-framework forming high-latitude coral communities47.
