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. 2018 Jul 18;8:10869. doi: 10.1038/s41598-018-29238-4

Table 2.

Relationship between environmental, microbiological, biochemical and biometrical parameters and the mortality-free time (D0) of oysters by univariate Cox proportional hazards models.

N Variable Estimate SE χ2 p Odds ratio
1 18:1n-9/18:1n-7last 0.117 0.020 32.91 <0.001 1.124
2 Distance to inshore oyster farms −0.741 0.134 30.49 <0.001 0.476
3 Turbiditymean 0.229 0.042 30.21 <0.001 1.257
4 16:1n-7/16:0mean −0.180 0.035 26.78 <0.001 0.835
5 TAG/STlast −0.685 0.140 23.91 <0.001 0.504
6 Bathymetry −0.324 0.069 22.01 <0.001 0.723
7 PUFA/SFAlast −0.035 0.008 20.45 <0.001 0.966
8 Flesh mass −0.400 0.091 19.54 <0.001 0.670
9 Branched +15:0 + 17:0last 2.512 0.569 19.47 <0.001 12.326
10 Turbiditylast 0.373 0.086 18.91 <0.001 1.451
11 TAGlast −0.101 0.024 18.23 <0.001 0.904
12 Fluorescencelast −0.174 0.041 18.00 <0.001 0.840
13 Shell mass −0.246 0.059 17.33 <0.001 0.782
14 Salinitylast 0.544 0.131 17.18 <0.001 1.722
15 PUFA/SFAmean −0.056 0.014 16.84 <0.001 0.945
16 Bacteria in seawaterlast 0.000 0.000 16.75 <0.001 1.000
17 Total body mass −0.285 0.070 16.54 <0.001 0.752
18 Fluorescencemean −0.655 0.164 15.92 <0.001 0.520
19 16:1n-7/16:0last −0.103 0.027 14.21 <0.001 0.902
20 Oxygenlast −0.083 0.023 12.85 <0.001 0.920
21 18:2n-6 + 18:3n-3last 1.385 0.395 12.33 <0.001 3.997
22 Carbohydrate last −0.014 0.004 12.14 <0.001 0.986
23 20:5n-3/22:6n-3mean 0.032 0.009 11.61 0.001 1.032
24 Branched + 15:0 + 17:0mean 3.798 1.210 9.84 0.002 44.606
25 Shell length −0.044 0.014 9.48 0.002 0.957
26 Temperaturemean −0.799 0.269 8.84 0.003 0.450
27 TAG/STmean −0.519 0.191 7.38 0.007 0.595
28 Vibrio in oystermean −0.192 0.071 7.21 0.007 0.825
29 Carbohydratemean −0.017 0.007 6.28 0.012 0.984
30 18:1n-9/18:1n-7mean 0.080 0.032 6.14 0.013 1.083
31 TAGmean −0.071 0.032 4.82 0.028 0.931

When a variable was acquired more than once between deployment and D0, mean value (mean) and the value recorded before the onset of mortality (last) were used, except for the biometrical parameters where the overall growth rates were used. Only the significant parameters are presented and sorted in ascending order of χ2. Values of 18:1n-9/18:1n-7, 16:1n-7/16:0, PUFA/SFA and 20:5n-3/22:6n-3 were multiplied by 100 and concentrations of bacteria and vibrio in seawater and oysters were divided by 1000 to obtain manageable odds ratio.