Figure 1 : Location of sites used in the study. (A) Governor
Island NTR and Trap Reef with inset showing study region; (B) Cape Lodi;
and (C) Butlers Point. Underlying bathymetric mapping layer shown in
colour. Black lines show locations of repeated AUV transects. All sites
were surveyed by AUV in 2011, 2013 and 2016; the Governor Island NTR was
also surveyed in 2014.
Figure 2 : Percent barrens at each of the sites through time.
Percent barrens were calculated as the precent of total images scored
that were classified as barrens. For Governor Island NTR images for all
transects were pooled at each time step. Note that the control sites
were not surveyed in 2014. Error bars are standard errors.
Figure 3 : Expected probability of barrens presence for (A)
depth and (B) rugosity. Expected probabilities were calculated by taking
5000 posterior draws from the fitted spatio-temporal model and holding
all other fixed effects constant while exploring a range of values for
the relevant covariate. Lines are posterior means and shaded areas 95%
credible intervals. We chose the NTR in 2016 to calculate the expected
probability and set the spatial random effects to zero. The mean value
in the NTR for rugosity was used when exploring depth, and the mean
value for depth and depth-squared in the NTR was used when exploring
different rugosity values.
Figure 4 : Posterior densities for the (A) spatial range and (B)
spatial standard deviation.