Zonation in a cryptic Antarctic intertidal macrofaunal community
Despite the general view that the Antarctic intertidal conditions are too extreme to support
obvious signs of macrofaunal life, recent studies have shown that intertidal communities can survive over
annual cycles. The current study investigates distribution of taxa within a boulder cobble matrix, beneath
the outer, scoured surface of the intertidal zone at Adelaide Island, west Antarctic Peninsula. The intertidal
zone at the study sites comprised compacted, flattened cobble pavements, which have been shown to be
highly stable over time. Community structure was investigated using univariate and multivariate
approaches. Virtually no macrofauna were present on the outer surface, but richness, diversity, abundance
and size of animals increased with depth into the rock matrix. Abundance of taxa increased by an order of
magnitude between the outer surface and the lowest level sampled. These findings show that the Antarctic
intertidal is not always the uninhabitable environment currently perceived, and that under these highly
variable environmental conditions at least some species have the capacity to survive.