Fall 2012

Document Type

Master's Thesis (Open Access)

Degree Name

Master of Science (M.S.)


Science & Environmental Policy


Habitat composition and complexity can play an important role in structuring populations of marine organisms. However, the interactions between the physical and biological landscape and their combined effect on marine population dynamics are not well understood. In this study, I explored the role of habitat complexity (three-dimensional habitat structure) on habitat composition (abundance and distribution of habitat types) and their combined role in structuring genetic variation in populations of the black surfperch Embiotoca jacksoni, within Monterey Bay, California. Black surfperch have no pelagic larval stage, limited adult dispersal, and associate strongly with benthic habitat making them an excellent model system for this study. Structural complexity of subtidal habitat was calculated using digital elevation models of the sea floor. Habitat composition was estimated from photoquadrats of the subtidal benthos and collections of benthic algal samples, which were sampled for the surfperch’s major prey sources in order to calculate prey biomass and distribution. Surfperch were collected for tissue samples and their stomach contents were analyzed for prey categorization (species and size distribution). We used 10 microsatellite markers to generate allele frequencies. GIS and spatial statistics were used to visualize and analyze the relationship between subtidal landscape variables and genetic diversity in black surfperch populations. This approach can provide rigorous quantitative estimates on the relationship between subtidal landscape complexity and genetic diversity in nearshore marine organisms.