Fauna associated with morphologically distinct macroalgae from Admiralty Bay, King George Island (Antarctica)

There are important gaps to understand the composition of the fauna associated with macroalgae, such as, how distinct algal morphology and environmental features, like turbulence or circulation patterns, may affect the distribution of them. In this study, macroalgae and associated fauna samples were undertaken between 4 and 12-m depth at three sites within the Admiralty Bay, King George Island, during the austral summer of 2000/2001. Previous physical oceanography data from the bay showed that each of these sites featured different circulation regimes. Differences and similarities in composition and density of the fauna associated with five species of macroalgae with different morphologies were analyzed: foliose (Monostroma hariotii and Palmaria decipiens); mixed (Myriogramme mangini); and branched (Desmarestia menziesii and Phaeurus antarcticus). Results showed differences in density, dominance of taxa, and richness among taxonomic groups of the associated fauna were related to algal morphology and circulation patterns. The dominance of epifaunal groups among macroalgae (e.g., D. menziesii, M. hariotii, and M. mangini) showed an adaptive response to different water flow settings within the bay, particularly in the community under the most intense flow. Further studies on associated fauna, should consider other environmental physical features and take our study like baseline to understand how major processes (e.g., climate change, seawater properties and circulation) may affect the communities, especially in more vulnerable shallow water zones.