Meeting Abstract

S7-2.1  Saturday, Jan. 5  Ecomechanics of marine mussels: do they really go with the flow? CARRINGTON, E; University of Washington ecarring@u.washington.edu

Common features of many temperate rocky coasts are dense aggregations of bivalve mollusks, or mussel beds, which exclude other space occupiers and provide refuge habitat for a diverse assemblage of organisms. One key to the mussel�s ability to dominate primary substrate is a strong attachment formed by numerous byssal threads. These extensible tethers are molded one-at-a-time in the mussel foot, a process that can be repeated every few minutes. Byssal threads have a limited lifetime (1-2 months), thus the attachment strength of an individual mussel reflects the balance of thread production and decay. Mussels therefore have the potential to finely �tune� their tethers to match their flow environment (increasing strength when higher flow generates forces that threaten dislodgment). Indeed, attachment strength is one phenotypic trait that is well known to be highly variable both spatially and temporally in mussels. In this study, the extent to which mussels are appropriately tuned to their flow environment is evaluated. Across broad flow gradients, several adaptations to reduce dislodgment risk in high flow are apparent; species inhabiting the most extreme wave-exposed shores are proportionally smaller and stronger than their wave-sheltered congeners. However, several cases are presented where mussel attachment strength does not appear to �go with the flow� and possible explanations for these mismatches between physiological tolerance and environmental challenge are discussed.