Recruit abundances of <i>Austrominius modestus</i> over time.

<p>(a) Mean recruit abundance (± SE) in 25 cm² control and cumulative plots every 2 wk (<i>n</i> = 10), (b) mean recruit abundance (± SE) in plots of difference area (cm²) (<i>n</i> = 10), and (c) mean recruit density per cm² in cumulative plots in plots of different sizes (<i>n</i> = 40). Letters over bars (a–d) indicate post-hoc comparison outcomes with the same letter indicating no significant difference between recruit abundance/density. All plots irrespective of initial clearance size are pooled in (b). The period when all cumulative plots were 100% colonised is shown (dotted line).</p

Comparative recruit density in cumulative and control plots.

<p>Change in recruit abundance in 25 cm² control and cumulative plots. Recruitment was estimated every 2 wk using non-destructive photographic sampling and image analysis. Control plots were disturbed (cleared) every 2 wk and estimates are compared to its paired cumulative plot on the same statue. Cumulative plots were undisturbed following the initial clearance. Significant regression is shown (solid line; <i>R</i>² = 0.89) and dashed lines indicate 95% confidence intervals. 45^o line indicates the point where recruitment is the same in control and cumulative plots.</p

Location of the 100 Antony Gormley statues (numbered) at Crosby Beach, Liverpool.

<p>Locations of the statues are shown in relation to Great Britain. Also showing the direction of sampling positions used to assess barnacle abundance on the statues (north, south, sea, or shore) (Ordnance Survey © Crown copyright 2011).</p

Mean total abundance of barnacles (25 cm⁻²) per sampling position

<p><b>on each of the 100 statues.</b> In total 14 sampling positions were chosen to represent a range of environmental conditions experienced by the statues and were located at the same points on each of the 100 statues sampled at Crosby Beach, Liverpool (for statue locations see Fig. 2). Boxplots show the medians (thicker black line) and upper and lower quartiles of abundance values at each sampling point, with whiskers extending to the extremes of data points not considered to be outliers.</p

Predicted changes in log barnacle abundance (25 cm⁻²) in relation to shore height and direction.

<p>Sampling positions faced four different directions: north, south, sea, shore. Values are based on those predicted from a generalized linear mixed model output using the median value of Location (first principal component of latitude and longitude), the mean level of Rugosity of the sampling positions and exposed or sheltered levels of Exposure.</p

Goodness of final model fit

<p><b>used to assess barnacle abundance on the statues at Crosby.</b> Goodness of fit of the final generalized linear mixed model is illustrated through assessment of the fitted values of the selected final model against the residuals of the model (red line indicates loess smoother).</p

Examples of the life-size cast-iron statues at Crosby Beach, Liverpool.

<p>Images show two of the 100 statues that form the art installation ‘Another Place’; one at the higher end of shore height sampled (left) and one at a lower shore height (right). The statues stretch over approximately 3 km of the foreshore and are distributed at a range of tidal heights.</p

Generalized linear mixed models (GLMMs) of barnacle abundance (numbers 25 cm⁻²) in relation to important environmental variables at Crosby Beach, Liverpool.

<p>Model selection was based on Akaike’s Information Criterion (AIC) with additional interactions being kept if they reduced AIC by >2. The most parsimonious adequate model on this basis is shown in bold. <i>n</i> = 1400 quadrats; d.f., degrees of freedom; <i>l</i>, log-likelihood; Δ AIC, the difference in AIC from that of the most parsimonious adequate model.</p

Predicted mean abundances of barnacles (25 cm⁻²) per statue position

<p><b>in relation to their location.</b> Predicted mean abundances are based on predicted values from a generalized linear mixed model output, with contours indicating actual shore height of the statues.</p

Parameter estimates for the final generalized linear mixed model (GLMM) assessing the influence of various factors on the abundance of barnacles.

<p>Parameter estimates for the final generalized linear mixed model (GLMM) assessing the influence of various factors on the abundance of barnacles.</p