Department of Marine Science
Geomorphic Controls over Littoral Communities in California
It has been suggested that the distribution of many species, and structure of many habitats, is constrained initially by broad scale variability in coastal geomorphology and geology. Thus the spatial characteristics of rock types can be an important determinant of the types of organisms that can settle, grow, and survive in a given location. A faulted rock substratum creates crevasses that can be colonized by marine organisms such as abalone. Harder, weather resistant rocks form promontories that can affect local circulation, the locations of coastal upwelling centers and ultimately the formation of the large intertidal communities that occupy these headlands. At scales below which ecologists traditionally study these systems, the microscopic scale, rock micro-textures can also effect the benthic community that emerges in a single location. For instance, rocks can be rugose and hard at the microscale but appear to be smooth and friable when observed at larger scales. Consequently, the controls that rocks can exert on intertidal ecologic processes such as recruitment, growth and survival vary with varying sizes and types of organisms and with the spatial scale at which rock-organism interactions occur. Hence a strong geological habitat/species relationship may exist across multiple spatial scales and these relationships are strongly dependent on the scale of observation.
As part of a collaboration with Moss Landing Marine Lab we are developing high resolution, three dimensional models of intertidal communities in California that can be used to quantitatively assess the relationship between geomorphology and community structure in the rocky intertidal. This project will result in the development of new interdisciplinary methodological approaches and tools to study California’s coastal environments. Funding for this project is provided by the California State University Council on Ocean Affairs Science and Technology.