Published online by Cambridge University Press: 17 July 2014
Community structure, species composition, and changes over time after disturbances are frequently studied using common descriptors. We used rank abundance distribution plots (RADs), Rényi entropy plots, common theoretical community models, ordination analysis of similarities (ANOSIM and Clusters), and abundance spectra analyses to study the effects of a gradual natural population decline and an anthropogenic punctuated disturbance on the structure of octocoral communities in Panama, considered a hot spot area for octocoral diversity in the Tropical Eastern Pacific. Over a 17-month period, no significant change was found in community structure after a natural yearly population decline of 25.2%. After a disturbance, however, different recovery trajectories were observed in various coral communities. Possible physical and biological explanations for the observed differences include initial local species diversity and abundance, species life history patterns, colony morphology, and the geographical location of the community. Differences in community structure between study sites were best described using a combination of community descriptors, RADs, and abundance spectra. Rényi plots were useful in identifying changes in community structure, whereas the extent of the changes was best evaluated using ANOSIM and cluster analysis.