Interactions between water flow and aquatic vegetation strongly depend on morphological and biomechanical characteristics of vegetation. Although any physical or numerical model that aims to replicate flow-vegetation interactions requires these characteristics, information on morphology and mechanics of vegetation living in coastal waters remains insufficient. The present study investigates the mechanical properties of blades of Saccharina latissima, a seaweed species spread along the shores of the UK and North East Atlantic. More than 50 seaweed samples with lengths spanning from 150 mm to 650 mm were collected from Loch Fyne (Scotland) and tested. Seaweed blades had a natural ‘stretched droplet’ shape with bullations in the central fascia and ruffled edges in the area close to the stipe. Their morphological features showed high variability for samples longer than 400 mm. The blades were almost neutrally buoyant, their material was found to be very flexible and ductile, being stiffer in longer blades. The laboratory tests showed that estimates of tensile Young's modulus appeared to be similar to bending Young's modulus suggesting a reasonable degree of isotropy in studied seaweed tissues.
Bibliographical noteThe work described in this publication was conducted during the Ph.D. study of D. Vettori, funded by the Northern Research Partnership and the University of Aberdeen, Scotland, UK. The authors thank Olivia McCabe for her contribution to conducting morphological and mechanical tests, David Attwood and Hamish Biggs for their assistance during seaweed collection and transport to the University of Aberdeen.
- Brown alga
- Mechanical properties
- Organism morphology
- Saccharina latissima