Seasonality and disturbance recovery of the epibenthic community on a warm-temperate hard bottom

Abstract

Hard bottom communities are variable systems controlled by physical environmental factors, and can be altered by disturbances. Biological factors such as competition, predation, and recruitment can also exert control on the structure of hard bottom communities. Community composition and recovery were measured at three sites on a nearshore hard bottom community in Onslow Bay, North Carolina. Seasonality and recovery of macroalgae and sessile invertebrates were evaluated at a frequency that would allow for an effective assessment of temporal change over a consecutive 16 months (24 May 2016 to 15 Sep 2017). Temporal communities were designated by grouping consecutive sampling days that did not differ (p ≥ .05). Community composition was significantly different between established temporal communities and sites (p < .001). Recovery within experimentally disturbed quadrats differed from corresponding controls depending on the state of the community before the disturbance. Specific taxa were identified as ‘important’ in differentiating temporal communities and sites for community composition. Seasonal temperature changes help explain the temporal patterns, and patchiness can justify the spatial variation. The transition through temporal communities can be related to consistent physical environmental factors, like temperature, but disturbances can introduce variability.