 Despite Heard Island's isolation, species richness is considered to be moderate, rather than depauperate, although the number of endemic species reported is low.The large macro-alga "Durvillaea antarctica" supports a diverse array of invertebrate taxa and may play an important role in transporting some of this fauna to Heard Island.The rocky shores of Heard Island exhibit a clear demarcation between fauna of the lower kelp holdfast zone and the upper shore zone community, probably due to effects of desiccation, predation and freezing in the higher areas.