AVENI-DEFORGE, Kyle*; WETHEY, David S; University of South Carolina, Columbia: Fortuna dubia: Byssal function in marine mussel adaptation to seasonal changes in wave energy

Mussels are dominant space competitors on intertidal rocky shores. They occupy space on rock by attaching extra-cellular shock absorbing fibers to their surroundings. Continuous force records during mussel dislodgement from substratum demonstrate that low wave energy adapted animals have low attachment strength and piecewise failure of the byssal apparatus. High wave energy adapted mussels have high attachment strength and exhibit catastrophic failure of the byssus. The period of transition between seasons of low wave energy to seasons of high wave energy is predicted to have the greatest probability of individual dislodgment by hydrodynamic forces. Here we use forces measured on mussels in breaking waves in concert with the continuous force records of mussel extraction to explore the importance of byssus structure on seasonal wave force adaptation, and to estimate the seasonality of risk of dislodgement.