Meeting Abstract

68.1  Jan. 7  Modeling the Mottling, How Mussel Beds are Prone to Patchiness AVENI-DEFORGE, K.*; WETHEY, D. S.; Univ. of South Carolina, Columbia kyled@biol.sc.edu

Mussels are dominant space competitors in the rocky intertidal. Solitary mussels produce byssal threads, extra-celluluar, shock absorbing fibers, to the substrate in order to resist dislodgement by the forces of lift and drag. The mussels� ability to deal with intense hydrodynamic forces is facilitated by the formation of dense aggregations, in which mussels not only reduce the hydrodynamic forces impinging on their shells by changing orientation, but also reduce the individual investment in byssal thread production, by attaching threads to neighboring shells as well as to the substrate. The number of neighbors with which a mussel interacts, and the number of byssal threads involved in those interactions generate a network through which forces are distributed, and the mussel bed is tied together. The clearing of patches is thought to be initiated by the loss of an individual, or clump of mussels, destabilizing the immediate neighborhood of the loss, and resulting in a chain reaction of dislodgement, creating a gap in the bed. Here we present an interacting particle model that incorporates empirically determined parameters for thread production, shell orientation, and interaction between aggregation members. The model demonstrates that mussel beds are intrinsically prone to patchiness, affirming that the loss of an individual can substantially destabilize a small neighborhood of mussels. However, the model also shows that there are check-points within aggregations that may help to prevent the spread of gaps.