UC Marine Council

Despite its significance and protected status, the intertidal region is being increasingly impacted by human activities such as harvesting, trampling, disposal of effluents and development. Major coastal engineering projects in Santa Cruz County armor eroding cliffs to stabilize the shoreline, reducing sand production and the amount of native substrate available for intertidal flora and fauna. 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. 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) attempt to link those patterns to life history characteristics. My approach is to characterize physical attributes of the different rock types including porosity, rugosity, and thermal capacity. I will perform series of clearings to see how recruitment varies on different rock types.

The importance of substrate type on community structures has been studied infrequently, partly because geologic differences generally occur over large spatial scales and transplantation studies (translocating rock types) are difficult. 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 Monterey Bay National Marine Sanctuary with respect to the rocky intertidal communities of plans and animals.