Rockpool complexity data from the Illawarra Australia (2020)

With the world currently in a state of environmental decline and habitat degradation, it is imperative that the influence of complex habitats on the assemblages of organisms is studied before they are lost. Many hypotheses have been proposed to explain the relationship between habitat complexity and organism abundances, such as the ‘greater niche hypothesis’ and the ‘species -area relationship’. Rockpools are discrete and ecologically dynamic environments, making them ideal candidates for studying habitat complexity. The primary aim of this study was to investigate the relationship between habitat complexity and the rockpool fish assemblages of south-eastern Australian. A total of 54 pools across 5 sites along the Australian Illawarra coastline were sampled using a mini baited underwater video system. Habitat complexity was quantified using both traditional manual measuring methodologies (pool width, depth, number of benthic rocks equal or greater than 10cm in size, algal cover and dominant substrate) and remote-sensing (rugosity). Maximum depth, width and the number of benthic rocks were significant predictors of species richness and total abundance. However, rugosity did not significantly predict species richness or total abundance. Therefore, these results highlight the role of habitat complexity in structuring animal assemblages, and the utility of multiple methodologies in quantifying complexity in small discrete habitat patches. This knowledge can be used to aid preserving complex areas to maximise abundance and diversity.