Impact of mechanical disturbance timing on early succession of seaweed assemblages in intertidal rock pools

Disturbances strongly impact macroalgal communities in intertidal rock pools. The timing of disturbance is a key factor that affects community characteristics. However, the effect of disturbance can differ strongly between locations and sites, stressing the need for local research. Moreover, prior studies have mostly considered disturbances on large time scales. Therefore, this experimental study investigated the effect of the timing of mechanical disturbances at intervals of less than a month on early recolonization of seaweed assemblages in intertidal rock pools of a Mediterranean rocky shore (Passetto di Ancona, Adriatic Sea). Additionally, the composition and structure of undisturbed seaweed assemblages in the same pools were studied over a 5-month period. In the recolonization process, the most apparent pattern in species composition consisted of differences between pools, but at $\pm$40 days after disturbance, a difference in community dissimilarity and total coverage between treatment times was found. In addition, there were some differences between treatment times in terms of diversity and abundance of individual species. In the descriptive sampling, there were clear differences between pools in terms of seaweed community composition, species diversity and coverage of single taxa within most sample dates. This variation was not consistent and varied over time.