(full paper is archived in the Miller Library)
Title: Community structure, environmental stress, and spatial variability in the intertidal zone at Hopkins Marine Station
Student Author(s): Asbeck, Lynn
Faculty Advisor(s): Denny, Mark
Location: Final Papers biology 175H
Date: June 2003
Abstract: Marine ecologists have traditionally used wave exposure to divide the intertidal zone into communities (Ricketts and Calvin 1985). This project used species abundance data from a horizontal transect at Hopkins Marine Station, combined with physical data about these sites to study horizontal variation in community structure. Cluster analysis upholds traditional ecological descriptions of population structure, in that clusters of species can be attributed to areas of certain wave exposure. However, regression analysis reveals that some species commonly found together had different physical parameters driving their distribution. For example, Lottia giagantea is positively correlated with wave force, but shows no correlation with temperature, azimuth and altitude angles, or the presence of crevices in the rocks. L. giagantea’s clustermate and prey, Hidenbrandia spp., has a negative correlation with altitude angle, but no correlation with wave force, azimuth angle, temperature, or presence of crevices. A smooth horizontal gradient of species does not exist at Hopkins Marine Station. The complex shape of the shoreline causes physical parameters at each site to be uncorrelated with those at neighboring sites and as a result, the horizontal distribution of species at HMS is patchy.