The stress and strain of life – how differences in the mechanical properties and cellular composition enable the kelp Laminaria digitata to thrive in different hydrodynamic environments

Sessile organisms such as macroalgae located in the intertidal and shallow subtidal zones are subject to a hydrodynamically diverse environment, controlling variation of intraspecific morphology distribution. Kelp forests experience both waves and/or currents, yet, how kelp blade material mechanically differs between these various hydrodynamic environments what drives strength extensibility not fully understood. Here, mechanical properties, cellular composition tissue thickness meristematic region distal tips Laminaria digitata blades were quantified compared seasons among three environments: wave dominated, current dominated benign environment. Kelps associated with energetic environments, generally tended be stronger yet more extensible than those growing Higher was at whereas tip blade. Linking results suggest enhancement medulla cells increases extensibility, potentially protecting thallus during increased storm activity while wave/current exposed habitat. Investment cortex towards suggests an increase region, which is susceptible breakage. However, lack proportion layers distinct revealed that potential overall strategy for avoiding breakage investing energy into tissue.