Experimental clearings in macroalgal (Ascophyllum nodosum) stands were established in 1996 to determine if mussel beds and macroalgal stands on protected intertidal shores of New England represent alternative community states. Circular clearings 1, 2, 4 and 8 m in diameter were made in Ascophyllum stands at 12 sites on Swan’s Island, Maine. Each site also had an uncleared control. The sites are nested within four bays. The purpose of this data set is to provide access to data on densities and percent cover in the 60 experimental plots from 1996 to 2002. Data include densities of mussels (Mytilus edulis and Modiolus modiolus), an herbivorous limpet (Tectura testudinalis), herbivorous snails (Littorina littorea, Littorina obtusata), a predatory snail (Nucella lapillus), a barnacle (Semibalanus balanoides), and fucoid algae ( (Ascophyllum nodosum and Fucus vesiculosus), and percent cover by mussels, barnacles, and fucoids. Published analyses of the data set show that succession depends on clearing size and not on site-specific differences.
Key words: alternative stable states; community ecology; Gulf of Maine; LTREB data; marine algae; marine invertebrates; mussels; rocky intertidal shores; succession.