Results of 3 PERMANOVA analyses testing drivers of community dissimilarity in a) high, b) mid, and c) low intertidal zones in Oregon and northern California from 2006–2021.

We tested the effects of site (nested within cape) as a random factor and the effects of climate variables for mean Pacific Decadal Oscillation index (mean PDO), mean North Pacific Gyre Oscillation index (mean NPGO), mean El Niño Southern Oscillation index (mean ENSO), mean and standard deviation of the Biologically Effective Upwelling Transport Index (mean and SD BEUTI, respectively), mean daily sea surface temperature (Mean SST), mean daily maximum air temperature (Max Air Temp), and years since the sea star wasting disease epidemic (Yr Since SSWD). Communities were analyzed at the quadrat level in the mid and high zones (0.5 x 0.5m) and the transect level in the low zone (the average of ~10 0.5 x 0.5m quadrats). Bold statistics indicate that >10% of variation was explained by a given factor.