Dataset: Rock Wall Experiment

The experiment was conducted on a vertical rock wall in the mid-high intertidal zone of Bodega Marine Reserve, Bodega Bay, CA, USA. Grazer diversity and substrate heterogeneity were factorially manipulated in 20cm x 20cm plots. Grazers were manipulated via direct removals from plots in order to generate monocultures of each of three gastropod taxa, the limpets, Lottia digitalis and Lottia scabra, and the snails Littorina spp. (L. plena and L. scutulata), along with an unmanipulated polyculture with all three gastropod grazers. Substrate heterogeneity was manipulated by scraping barnacle covered areas from the rock surface. Three barnacle treatments were used: two homogeneous treatments (full = no barnacle removal, none = all barnacles removed) and one heterogeneous treatment (half = barnacles removed from one half of plot but left intact on the other half). Grazer and substrate treatments were maintained over time by counting and removing unwanted grazers from plots and by removing new barnacle recruits from previously cleared areas. On each survey date, grazer abundance and visually-assessed percent cover of algal taxa were recorded.

Reference:
Matthew A. Whalen, Kristin M. Aquilino, John J. Stachowicz. 2016. Grazer diversity interacts with biogenic habitat heterogeneity to accelerate intertidal algal succession. Ecology. in press.