OSBORN, Dawn: Rock type: Does it matter for intertidal community ecology?

The importance of substrate type on community ecology has been studied infrequently, partly because geologic differences generally occur over large spatial scales and transplantation studies are difficult. The extensive anthropogenic armoring of the shorelines provides an unusual opportunity to determine the effect of differing rock types on intertidal community assemblages and sets the stage for experiments in the field. Along the populated coastline of California, there is the opportunity to compare native rock types and introduced rocks from quarries. The geology of the coastline has been changing as these structures modify the coastal substrate, adding a mixture of metamorphic and igneous rock to the sandstone and mudstone cliffs. At the same time, public concern is growing about the impacts to the shoreline that result from anthropogenic input. The effects of these changes have not been directly looked at in the Monterey Bay National Marine Sanctuary with respect to the rocky intertidal communities of plants and animals. The goals of this project are: 1.) to determine if rock type influences zonation patterns, 2.) to determine if there is a difference in community assemblages relating to different rock types, 3.) to demonstrate the mechanism responsible for these differences, and 4.) to link those patterns to life history characteristics.