Date of Award

Winter 2006

Project Type


Program or Major


Degree Name

Master of Science

First Advisor

Michael P Lesser


Historical concepts of top-down control (predator-prey interactions) on rocky intertidal community structure have transitioned to studies on bottom-up effects (nutrient supply and larval transport) as significant factors affecting rocky intertidal community structure. Studies performed on rocky intertidal locations along the Gulf of Maine (GOM) at multiple sites and seasons in 2004 and 2006 examined the ecology of Mytilus edulis populations by measuring size frequency distributions, diet quality (stable isotope composition) and physiological performance of individuals using condition indices and RNA/DNA ratios. Data were correlated to satellite imagery for sea surface temperature and chlorophyll a concentration and individuals were genetically tested to look for lineage sorting. Populations of M. edulis in the GOM were found to be genetically homogenous, consuming a mixed diet of phytoplankton and detritus, with shell size and physiological performance tied to chlorophyll a concentration and temperature, providing strong evidence for community structure being linked to environmental variability.