%0 Journal Article
%T TROPHIC STRUCTURE AND BIOMASS DISTRIBUTION OF MACROBENTHOS ON SHELTERED AND SEMI-EXPOSED ROCKY SHORES OF TSITSIKAMMA MARINE PROTECTED AREA.
%A Nicholas Hanekom
%J African Zoology
%D 2012
%I 
%X The trophic structure and biomass of macrobenthos on both wave sheltered, rocky intertidal shores and semi-exposed ones at seven localities in the Tsitsikamma Marine Protected Area were compared. In the Cochlear zone and entire intertidal (Cochlear- and Balanoid zones combined) biomass values of invertebrates and filter-feeders were significantly (P < 0.05) higher at semi-exposed shores, while grazer biomass was greater at sheltered sites: a negative relationship (P < 0.01) and a moderate to weak correlation (r > 0.42) was also recorded between filter-feeder biomass and grazer biomass. This negative relationship reflected changes in standing biomass of the two dominant filter-feeders (Octomeris angulosa and Perna perna) against that of the dominant grazers (Scutellastra cochlear). On sheltered shores the biomass of trophic groups varied significantly (P < 0.05) across the intertidal gradient studied, with values of grazers and algae decreasing with increased aerial exposure. Similar, but less substantial (P > 0.05) variations were recorded at semi-exposed sites, where the median shell length of the brown mussel P.  perna decreased upshore (P < 0.05). Multivariate analyses of square-root transformed biomass values separated most of the sheltered Cochlear zone stations from semi-exposed ones. This study supported the concept that the structure of low-shore communities is determined largely by differences in wave action.
%K rocky shore
%K invertebrate
%K algae
%K communities
%K wave exposure
%K biomass
%K trophic structure
%U http://africanzoology.journals.ac.za/pub/article/view/108