Table 1. Environmental predictor variables assessed in a multivariate multiple regression analysis (DISTLM) at sites within three sediment plume exposure categories determined by MODIS satellite imagery: low (0 to 9 plume exposure days, n = 6 sites), moderate (40 to 68 plume exposure days, n = 3 sites) and high (296 to 347 plume exposure days, n = 2 sites); and results of an analysis of variance (ANOVA) for each predictor variable among dredge plume exposure groups.
| Factor | Sediment plume Exposure Category | ||||||
| Low (n = 6 sites) | Moderate (n = 3 sites) | High (n = 2 sites) | ANOVA | Assessed in | |||
| mean (SE) | mean (SE) | mean (SE) | F(2,11), p | DISTLM? | Source | ||
| Dredging: | Sediment plume exposurea daysa | 2.0 (1.5) | 62.3 (11.5) | 321.5 (25.5) | 285.7, <0.001* | Yes | [30] |
| Predation: | COTS scarsb | 0.0 (0.0) | 1.6 (1.1) | 0.0 (0.0) | 1.5, 0.29 | Yes | This study |
| Drupella scarsc | 3.6 (0.6) | 11.7 (3.3) | 1.4 (0.9) | 2.9, 0.11 | Yes | This study | |
| Coral cover: | Total hard coral coverd | 36.0 (15.0) | 53.5 (21.1) | 26.0 (20.4) | 1.7, 0.24 | Yes | This study |
| Thermal stress: | Peak SSTe | 30.7 (0.2) | 30.8 (0.3) | 30.9 (0.0) | 0.2, 0.81 | Nok | [34] |
| Peak SSTAf | 2.8 (0.1) | 2.7 (0.2) | 2.7 (0.0) | 0.07, 0.94 | Nok | [34] | |
| Hot Snapg | 2.0 (1.7) | 1.8 (1.4) | 2.2 (0.4) | 0.04, 0.96 | Yesk | [34] | |
| Winter Conditionsh | 10.3 (0.7) | 9.0 (0.1) | 8.0 (0.2) | 2.2, 0.18 | Yes | [34] | |
| MPSAi | 0.3 (0.1) | 0.2 (0.03) | 0.3 (0.01) | 1.2, 0.35 | Yes | [35] | |
| Modeled disease: | Predicted disease abundancej | 101 (94) | 88 (39) | 52 (57) | 0.3, 0.75 | No | [35] |
Number of days the sediment plume was recorded over a site for the duration of dredging operations (days).
Prevalence of coral colonies with crown-of-thorns seastar lesions determined by in situ coral health surveys (%).
Prevalence of coral colonies with Drupella lesions determined by in situ coral health surveys (%).
Total hard coral cover on transects determined by line intercept method (%).
Maximum sea surface temperature recorded during dredging operations (May 2010 to November 2011) (°C).
Maximum excursion of sea surface temperature from the long-term climatological value during dredging operations (May 2010 to November 2011) (°C).
Accumulation of thermal anomalies greater than the long-term summer mean temperature plus one standard deviation (°C-weeks).
Accumulation of winter anomalies (+ and −) from the long-term winter mean temperature (°C-weeks).
Average of summer temperature anomalies greater than zero calculated from the monthly mean temperature plus one monthly standard deviation.
Modeled numeric prediction of disease abundance based upon MPSA and total coral cover (disease cases per 1,500 m2).
Peak SST and Peak SSTA were excluded from the DISTLM due to a strong correlation with Hot Snap (r = 0.87 and 0.79, respectively).