The effects of armoring the coastline on intertidal flora and fauna

We study the effects of armoring the coastline on intertidal flora and fauna. The extensive anthropogenic armoring of the shoreline along the California coast provides an unusual opportunity to determine the effects of variation in substrate type on settlement and post settlement processes of sessile intertidal flora and fauna. Armoring is the addition of hard substrate, boulders or seawalls, to a zone where ephemeral rocks and sand once existed. Armoring is a biological disturbance, covering up native rocks and associated organisms. The interactions between intertidal organisms and substrates might play a significant role in structuring benthic communities influencing not only initial settlement, but also subsequent species assemblages. A series of clearings on basalt, sandstone and mudstone rocks and counting all invertebrates and weighing dried algae from the cleared substrates is performed. The goal of this paper is to determine if there is a difference in community assemblages relating to different rock types and if so, as seems likely, to demonstrate the mechanism responsible for these differences, and to link those patterns to life history characteristics.