Table S1 Generalized additive model with autocorrelation structure results and the associated Akaike information criterion (AIC) and adjusted r2 values for the hourly minimum (MinDepth) and maximum (MaxDepth) depth data calculated from the archived dataset for shark HG02. Covariates are: SamplingDate = chronological order of observation from April 1, 2011 at midnight; TimeOfDay = dawn, day, dusk or night factor. s=nonparametric smoothing function. The degrees of freedom (df), F-statistic and associated P value is provided for each smoother term. The t-value and associated P value is provided for covariates. Bold denotes models with lowest AIC value and statistically significant (P<0.05) model terms; all models exhibited autocorrelation patterns indicating that lagged dependence between observations could not be fully accounted for

Model and terms / AIC / r2 / term / df / F-statistic (P) of smoother / t-value (P) of covariate
MinDepth
s(SamplingDate) / 55679.38 / 0.54 / smoother / 8.845 / 652.6 (<0.001) / --
s(SamplingDate, by TimeOfDay) / 55472.72 / 0.57 / dawn smoother
day smoother
dusk smoother
night smoother / 7.689
8.739
8.350
8.618 / 104.4 (<0.001)
281.1 (<0.001)
73.7 (<0.001)
300.8 (<0.001) / --
--
--
--
s(SamplingDate) + TimeOfDay / 55561.04 / 0.55 / smoother
dawn coefficient
day coefficient
dusk coefficient
night coefficient / 8.847
--
--
--
-- / 663 (<0.001)
--
--
--
-- / --
74.33 (<0.001)
4.134 (<0.001)
2.934 (0.003)
-2.809 (0.005)
MaxDepth
s(SamplingDate) / 55670.06 / 0.55 / smoother / 8.819 / 689.1 (<0.001) / --
s(SamplingDate, by TimeOfDay) / 55564.8 / 0.57 / dawn smoother
day smoother
dusk smoother
night smoother / 7.397
8.656
8.099
8.560 / 88.31 (<0.001)
345.25 (<0.001)
69.92 (<0.001)
271.50 (<0.001) / --
--
--
--
s(SamplingDate) + TimeOfDay / 55554.1 / 0.56 / smoother
dawn coefficient
day coefficient
dusk coefficient
night coefficient / 8.822
--
--
--
-- / 699.1 (<0.001)
--
--
--
-- / --
90.194 (<0.001)
6.590 (<0.001)
1.313 (0.189)
0.103 (0.918)