Figure 1.
Location of sample sites, Andaman Sea, Thailand.
A) Map of the study area in the Andaman Sea off-shore the west coast of Thailand with inset showing the Andaman Sea from the Nicobar Islands Arc to the southeast Asian mainland of Burma and Thailand (Mainland: Wessel and Smith [79], Bathymetry: Smith and Sandwell [80]). B–F) Close-up maps of the study islands (Surin, Tachai, Bon, Similan, Miang and Racha) with sampling sites (UNEP Coral Millennium Project). Crosses: core sampling sites with high-resolution temperature monitoring and framework height determination (at Miang W and Surin W additional CTDs were deployed) ; triangles: sites where only framework height was measured (Tachai E and Racha E the present study, Similan E and W framework height derives from [16]). Scale bar represents 1 km.
Figure 2.
Reef framework height above bottom.
Reef framework height (mean ± SE) measured at all study sites. Open bars are E sites (a), black bars W sites (b), showing significant differences (Welch's t-test: t = 10.66, df = 131, p<0.001). Framework height is arranged from left to right with lowest to strongest LAIW (large amplitude internal waves) intensity (intensities were estimated for sites where no temperature record were available (Tachai E, Racha E)).
Figure 3.
Temperature record for the 6 core sampling sites (cf. Fig. 1) showing median (black lines) and quantil ranges in shades of grey (light gray: 0–1, intermediate gray: 0.05–0.95 and dark grey: 0.25–0.75). Sites are arranged from top to bottom (Miang E, Racha W, Bon W, Surin W, Miang W and Tachai W) with lowest to strongest LAIW (large amplitude internal waves) intensity.
Figure 4.
Negative temperature anomaly, sedimentation rate and grain size variation.
All parameters are displayed for the study period November 2009 to December 2011 for the core sampling sites (cf. Fig. 1). A) Negative temperature anomalies calculated as cumulative degree days (DD) per month. B) Temporal evolution of sedimentation rates (mean ± SE) as dry sediment mass per cm2. Deployment periods are indicated by the grey broken line parallel to the time axis. C) Grain size phi (mean ± SE) or diameter (mean ± SE [mm]). Grey shaded area corresponds to the SW-monsoon season May-November.
Table 1.
Spearman's rank correlation analyses of conductivity, pH and oxygen with temperature derived from CTD records at Miang W and Surin W (cf. Fig. 1) during December 2009 and March 2010 deployments.
Figure 5.
Reef framework height as a function of environmental parameters.
Reef framework displayed as a function of A) temperature anomaly (DD = degree days), B) grain size phi and C) sedimentation rate. Environmental parameters represent mean values for an entire year - 12.2009–12.2010 derived for the core sampling sites (cf. Fig. 1): A–C) Miang W, Miang E, Bon W, Tachai W, Surin W, Racha W and for A) additionally from Similan E and W [16]. Temperature anomaly values for Similan W and E were set equal to Miang E and W, respectively; justification see [16]. All values are given as mean ± SE.
Figure 6.
Reef framework height versus 2010 and 2011 dry season negative temperature anomaly.
Reef framework height plotted as a function of dry season temperature anomaly (DD = degree days) reflecting the negative temperature anomalies experienced during the peak large amplitude internal waves (LAIW) period for 2010 (grey error bars and regression line) and 2011 (black error bars and regression line) for core sampling sites (cf. Fig. 1) plus Similan E and W (temperature anomaly values were set equal to Miang E and W, respectively; justification see Schmidt et al. [16]). All values are given as mean ± SE.