Wind Forcing of Sediment Flux and Post-Larval Transport in a Patchy, Biogenically Structured Intertidal System

Sondra E. Winders, Gettysburg College

Environmental Studies Honors Thesis

Faculty Advisor: Professor John Commito


The blue mussel (Mytilus edulis) is a soft-bottom ecosystem engineer, influencing sediment and ambient community dynamics. Mussel beds, however, are not composed solely of live mussels. Four mussel bed cover types were identified in a Maine mussel bed: bare sediment, live mussels, whole shells, and fragmented shells. GIS analysis of the areal extent of each cover type revealed the live mussels covered only 1% of the study site, while bare sediment covered 65% and shell hash (whole shell and fragmented shell) covered 34%. Bottom traps were deployed to measure sediment flux, and absolute, relative, and bulk dispersal rates of macrofauna and meiofauna. Wind direction and wind velocity data were plotted using wind roses. Sediment flux and animal dispersal varied significantly across cover types and wind condition. While most studies focus only on live mussels as ecosystem engineers, this study demonstrates that to understand the important role mussels play in carbon sequestration and storm-surge protection, more attention must be paid to the biogenically structured cover types within bivalve beds and their effects on ecosystem processes.