Death By Small Forces:
However, this prediction is at odds with reality: many intertidal seaweeds experience consistent and substantial seasonal breakage and dislodgment. To resolve the disparity between prediction and reality, researchers have suggested that seaweeds break not due to maximum hydrodynamic stresses but due to the accumulated effects of repeated loading over time.
Video of puller in action:
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Why do seaweeds break? Surprisingly, this seemingly straightforward question remains unanswered. Biomechanists have long studied how wave-swept macrolagae thrive in the extreme water velocities imposed by pounding surf. In particular, traditional tests have measured strength of intertidal seaweeds by pulling specimens until they break, mimicking loading by individual waves. Comparison of measured strengths to maximum wave-induced stresses leads to the unexpected prediction that seaweeds should seldom break in the field. 
I study the slow breakage, or fatigue, of seaweeds. Because many building materials fail by fatigue, a variety of engineering methods exists for examining failure by repeated forces. Using fracture mechanics and fatigue analysis techniques, I characterize fatigue behavior of seaweeds, by repeatedly loading samples and then using collected “baseline” data to predict fatigue lifetimes (time to breakage) in the field. 
