Temporal variations (2000–2013) in fish and macrocrustacean density along the Sainte Cécile intertidal sandy beach using a centred PCA.

<p>A. Average position of the species in the two first principal components (PC1 and PC2). Contribution of each axis to total variance is shown in %. Scales of the axes are given in the boxes. Species associations were defined from hierarchical cluster analysis by Ward’s method of the species coordinates. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117220#pone.0117220.t001" target="_blank">Table 1</a> for species labels. B. Temporal variations in PC1 and PC2. Note that temporal trend in PC1 was highly significant (r² = 0.68, p < 0.005), and the absence of sampling in the years 2001–2002 and 2008.