Resistance of rocky intertidal communities to oceanic climate fluctuations

communities are widely expected to be particularly sensitive to a changing climate [99]. Sec- ond, other studies in this system have detected sensitivity of ecological processes to ocean cli- mate fluctuations like PDO, NPGO, ENSO upwelling, and temperature [20,54,62,64,100]. Third, there were multiple notable climate-related events during this time frame that we cap- tured in our analysis (Figs 2 and 3). Most notably, there were several concurrent and intercon- nected shifts in 2014–2016 that included a severe marine heat wave (“the blob”), a strong El Niño event, and a shift to less windy NPGO and warmer PDO conditions [46,47,101]. While Fig 8. Bivariate regressions between the percent cover of focal functional groups (significant functional groups in Table 2b with the 8 focal climate variables in the mid zone. Each data point is the average abundance of a functional group for a site and year. Environmental drivers included Pacific Decadal Oscillation (mean PDO), North Pacific Gyre Oscillation (mean NPGO), Multivariate El Niño Southern Oscillation Index (mean ENSO), Biologically Effective Upwelling Transport Index (mean BEUTI), the standard deviation in BEUTI (SD BEUTI), the maximum daily air temperature by site (Max Air Temp), the mean daily water temperature by site (Mean SST) and the years since the initial sea star wasting disease outbreak (Yrs since SSWD). Colors correspond to functional groups, with Endocladia muricata in red, mussels (Mytilus spp.) in blue, gooseneck barnacles (Pollicipes polymerus) in cyan, limpets in dark purple, and

predatory snails in light purple. Units are in percent cover except limpets and predatory snails are in density m-2. https://doi.org/10.1371/journal.pone.0297697.g008 PLOS ONE Resistance of rocky intertidal communities PLOS ONE | https://doi.org/10.1371/journal.pone.0297697 May 29, 2024 20 / 34