Changes in Abiotic Drivers of Green Sea Urchin Demographics following the Loss of a Keystone Predator

Figure 7

Principal component analysis (PCA) of environmental variables, coded by island group: Near Islands (circles), Rat Islands (diamonds), Delarof and Andreanof Islands (squares), Island of Four Mountains (down triangles), and Fox Islands (up triangles). The vectors depict the direction of change and strength of correlation with each axis.