Project
 
Title: Effects of wave period and force on tenacity of Acmaea mitra, the Whitecap limpet.

Abstract: Wave exposure is highly influential in the intertidal and shallow subtidal zone of rocky shores, impacting the structure, species distribution and biodiversity of ecosystems.  Waves affect the growth rates, reproductive success, and energy expended by individual organisms trying to maintain position in spite of omnipresent hydrodynamic forces.  Despite its biological importance, wave exposure is poorly understood and poorly defined.  Laboratory experiments involving the simulation of hydrodynamic forces on intertidal gastropods were conducted to examine the affects of substrata, angle of applied force, magnitude of force and period between forces on tenacity of the intertidal and shallow subtidal limpet Acmaea mitra.  Morphometric measurements were taken to allow prediction of how relative hydrodynamic forces change throughout the lifecycle of the limpets.  Acmaea mitra was found to be more tenacious on rugose surfaces than on smooth substrata, and more tenacious when force was applied at 90^o to the substratum than when it was applied at other angles. The average tenacity of A. mitra decreased proportionately with period and inversely with force.  Period, force, and the interaction of period and force all had significant affects on tenacity, with period affecting tenacity more at higher simulated fluid velocities than at lower velocities. Acmaea mitra were found to grow allometrically, with wet mass, frontal area and height growing faster than would be predicted by growth that was isometric with shell length.  Regression analysis produced a model to predict tenacity within the range of laboratory simulated conditions tested, Y = 1.697P -3.321F + 25.705 , where Y is tenacity in minutes cm^-2 of limpet pedal area, P is period and F is force.