Abstract
Fragmentation is a common reproductive and dispersal strategy used by marine macroalgae, and can facilitate the dispersal and establishment of species in the environment. Whereas some disturbances, such as storms, currents, and crashing waves can harm to algae, fragmenting algae can benefit from disturbances that spread their fragments to new areas. Water movement, sometimes in the form of wave surges and strong currents, can create large drag forces causing tension or bending stresses, primarily at the base of the stipe, leading to bending fractures and the ultimate fragmentation of an individual. Morphological traits, namely size, and its relation to physical properties such as tensile strength and flexibility are fundamental aspects of algae that may influence fragmentation, yet have remained understudied in marine algae. Further, few studies have examined size and plant-flow interactions and how they affect fragmentation in marine algae. Therefore, the objective of this study is to a) quantify the strength and flexibility of three species of algae using biomechanical tests, b) test how fragmentation varies with water flow in three macroalgae using lab experiments, and c) test how strength, flexibility, and fragmentation in flow vary with size (length of thallus, including the holdfast) within species.