Spatial and temporal variation in rocky intertidal communities along the main Hawaiian islands
Thirteen benthic rocky intertidal communities were quantitatively assessed on Maui, Moloka'i, O'ahu, and Hawai'i Island between the years 2004 and 2007. Our goals were to test for differences in invertebrate and macroalgal abundance and composition to understand how these tropical communities are organized. Percentage cover surveys revealed a diverse intertidal system with 49 macroalgal, 1 cyanobacterial, and 31 invertebrate taxa. Shores were frequently dominated by a few macroalgae and mollusks, and at two sites these organisms were distributed in discrete vertical bands. Common intertidal taxa included the introduced alga Acanthophora spicifera; species in the macroalgal genera Padina, Sargassum, and Laurencia; turf forms of algae; and the mollusks Siphonaria normalis, Nerita picea, and species of littorine snails. Multivariate statistics found community structure to vary among sites and years, but there was lack of evidence for island-specific or substratum-specific assemblages. SIMPROF analysis revealed support for 11 different types of structure. This first description of community-level patterns at multiple intertidal sites along the Main Hawaiian Islands documents substantial spatial variation both among and within shores, as well as substantial temporal variation for select sites. These findings are in contrast to the characterization of a homogeneous tropical system and thus suggest that biotic and abiotic factors in the Main Hawaiian Islands act on a local scale to drive structure.
Cox, T. E., Philippoff, J. K., Baumgartner, E., Zabin, C., & Smith, C. M. (2013). Spatial and temporal variation in rocky intertidal communities along the main Hawaiian islands. Pacific Science, 67(1), 23–45.