The effects of excluding limpets from the lower balanoid zone of rocky shores in Transkei, South Africa

Abstract

The effect of season (summer v. winter) on colonization by algae and barnacles in the lower balanoid zone following exclusion of grazers was investigated on two rocky shores in Transkei. Copper-based paint was used to establish exclusion and partial exclusion quadrats and these were compared with paint-free controls. Rapid regrowth of Enteromorpha and Ulva was observed in the exclusion areas irrespective of season. Greater temporal variability in algal cover was observed when the experiment was started in summer than in winter. There was little growth of algae in the partial exclusion or control treatments. Settlement of the barnacle Tetraclita serrata was enhanced in the exclusion areas, but barnacles settled sporadically in the other treatments. Seasonal effects were insignificant in colonization of areas from which grazers were excluded. © 1995 Taylor & Francis Group, LLC.