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Effects of a small-bladed macroalgal canopy on benthic boundary layer dynamics: implications for nutrient transport


Kregting, L and Stevens, C and Cornelisen, C and Pilditch, C and Hurd, CL, Effects of a small-bladed macroalgal canopy on benthic boundary layer dynamics: implications for nutrient transport, Aquatic Biology, 14 pp. 41-56. ISSN 1864-7782 (2011) [Refereed Article]

Copyright Statement

Copyright 2011 Inter-Research

DOI: doi:10.3354/ab00369


Field and laboratory velocity profiles were used to quantify boundary layer dynamics within communities of a small (< 0.2 m tall), dense canopy-forming seaweed Adamsiella chauvinii (Rhodophyta) in a soft-sediment habitat and to examine the role of hydrodynamics in modulating nutrient supply. At the ‘canopy scale’ there was a mixing layer at the fluid−canopy interface where turbulent kinetic energy was greatest, potentially enhancing nutrient uptake in this region. In the lower half of the canopy, a drag-dominated area of very low water velocity (< 0.01 m s−1) occurred. Spectral analysis revealed a reduction in energy within the canopy of around 1 Hz. The hydrodynamic parameters obtained from flume measurements were in good agreement with those recorded in the field. To understand the implications of the hydrodynamic environment on nutrient uptake, a flushing ratio was developed that compares the time for macroalgae to remove all nutrients from the canopy volume relative to the timescale for flushing. Results suggest that when nutrient demand is low, the canopy is well flushed and not mass-transfer limited. However when nutrient demand is high, the canopy can deplete nutrients more quickly than they can be replenished by ambient flows and are potentially mass-transfer limited.

Item Details

Item Type:Refereed Article
Keywords:seaweed, canopy dynamics, boundary layer, hydrodynamics, nitrogen uptake
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Phycology (incl. marine grasses)
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Adaptation to climate change
Objective Field:Ecosystem adaptation to climate change
UTAS Author:Hurd, CL (Professor Catriona Hurd)
ID Code:91470
Year Published:2011
Web of Science® Times Cited:18
Deposited By:IMAS Research and Education Centre
Deposited On:2014-05-20
Last Modified:2017-10-31

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