The influence of hydrodynamics on the growth, erosion and biomechanical properties of Laminaria digitata
type: CreativeWork
description: Kelp forests are described as one of the most productive marine habitats globally which cover approximately 25% of the world’s coastline supporting a diverse range of flora and fauna. There is also now a growing awareness that macroalgae may be significant contributors to blue carbon as it is estimated that ~90% of carbon fixed by macroalgae is transported by water motion and sequestered in coastal or offshore sediments. Macroalgae such as the kelp Laminaria digitata are found in temperate waters growing in the low intertidal region along energetic coastlines exposed to a range of hydrodynamic environments. The influence of water motion on fundamental processes such as growth, erosion and the mechanical properties of kelp has received some research, however, teasing apart the effect of waves and currents on the biology of kelp is unknown. Here a combination of field and laboratory experiments were conducted to establish the influence of wave and current motion on L. digitata (i) relative growth rate of the meristematic region and the entire blade; (ii) erosion rate from the distal end; (iii) mechanical properties of blade tissue (breaking stress and strain) (iv) and mechanism underlying the associated mechanical properties of L. digitata at three hydrodynamically different regimes: low current and low wave (LCLW), high current and low wave (HCLW) and high wave and low current (HWLC). Results suggest that differences in L. digitata relative growth rates were not attributed to the seawater nutrient concentrations or temperature but to the hydrodynamic environment. At the high current condition, kelp growth rate of the meristematic region was enhanced by 45% compared to the high wave condition. When including the entire blade growth rate, an average increase of 25% was observed between the high current and high wave condition. Potentially, the division in growth ii rate observed between the wave and current motion could be related to the frequency and magnitude at whic…
abstract: Kelp forests are described as one of the most productive marine habitats globally which cover approximately 25% of the world’s coastline supporting a diverse range of flora and fauna. There is also now a growing awareness that macroalgae may be significant contributors to blue carbon as it is estimated that ~90% of carbon fixed by macroalgae is transported by water motion and sequestered in coastal or offshore sediments. Macroalgae such as the kelp Laminaria digitata are found in temperate waters growing in the low intertidal region along energetic coastlines exposed to a range of hydrodynamic environments. The influence of water motion on fundamental processes such as growth, erosion and the mechanical properties of kelp has received some research, however, teasing apart the effect of waves and currents on the biology of kelp is unknown. Here a combination of field and laboratory experiments were conducted to establish the influence of wave and current motion on L. digitata (i) relative growth rate of the meristematic region and the entire blade; (ii) erosion rate from the distal end; (iii) mechanical properties of blade tissue (breaking stress and strain) (iv) and mechanism underlying the associated mechanical properties of L. digitata at three hydrodynamically different regimes: low current and low wave (LCLW), high current and low wave (HCLW) and high wave and low current (HWLC). Results suggest that differences in L. digitata relative growth rates were not attributed to the seawater nutrient concentrations or temperature but to the hydrodynamic environment. At the high current condition, kelp growth rate of the meristematic region was enhanced by 45% compared to the high wave condition. When including the entire blade growth rate, an average increase of 25% was observed between the high current and high wave condition. Potentially, the division in growth ii rate observed between the wave and current motion could be related to the frequency and magnitude at whic…
author: Millar, Rachel
language: eng
keywords: Macroalgae, Waves, Currents, Kelp, Hydrodynamics, Erosion
date published: 2020-7
date modified: 2026-07-24T03:55:18Z
provider: Queen's University Belfast
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Queen's University Belfast