Subtidal community shifts in the western Strait of Juan de Fuca from kelp dominated systems to urchin barrens following sea star wasting disease

Abstract

As the effects of climate change continue to induce environmental disturbances, it is important to understand how communities change in response. Research has established that environmental perturbations to the environment can result in community shifts. In this study, I describe shifts in kelp-dominated rocky reef systems associated with sea star wasting disease (SSWD). I used video transect data from five sites in the western Strait of Juan de Fuca collected over a 9-year period (2011-2019) to test whether community assemblages differed before and after the onset of SSWD. Results indicated significant temporal and spatial changes in community structures, with notable shifts occurring in 2016 at 4 of the 5 sites studied. Benthic communities at one site remained relatively unchanged over the study period. Marine mammal survey data indicates that sea otters (Enhydra lutris) are routinely present at this site, suggesting that the presence of sea otters can potentially dampen the effects of SSWD on subtidal communities.