Effect of a seagrass (Posidonia oceanica) meadow on wave propagation
نویسنده
چکیده
We demonstrate the utility of using the equivalent bottom roughness for calculating the friction factor and the drag coefficient of a seagrass meadow for conditions in which the meadow height is small compared to the water depth. Wave attenuation induced by the seagrass Posidonia oceanica is evaluated using field data from bottom-mounted acoustic doppler veloci meters (ADVs). Using the data from one storm event, the equivalent bottom roughness is calculated for the meadow as ks ~ 0.40 m. This equivalent roughness is used to predict the wave friction factor ƒw, the drag coefficient on the plant, CD, and ultimately the wave attenuation for other storms. Root mean squared wave height (Hrms) is reduced by around 50% for incident waves of 1.1 m propagating over ~ 1000 m of a meadow of P. oceanica with shoot density of ~600 shoots m−2.
منابع مشابه
Field observations of wave-induced streaming through a submerged seagrass (Posidonia oceanica) meadow
[1] This paper reports the findings of a 2week field campaign designed to study wave-induced flows within a meadow of Posidonia oceanica at water depth 9m. Previous laboratory experiments suggest that waves induce a mean mass drift in the direction of wave propagation (“streaming”) through submerged canopies of vegetation. This paper provides the first field measurements of this wave-induced st...
متن کاملResponse of the non-indigenous Caulerpa racemosa ̊ (Forsskal) J. Agardh to the native seagrass Posidonia oceanica (L.) Delile: effect of density of shoots and orientation of edges of meadows
Caulerpa racemosa is a tropical green alga introduced into the Mediterranean as an immigrant from the Red Sea which has successfully fast-spread in the south-eastern and in the north-western part of the basin. C. racemosa occurs mostly in shallow but also in deep subtidal habitats colonising hard and soft substrata where turfs, erect algae and even seagrasses are present with the potential to p...
متن کاملOrganic Carbon Metabolism and Carbonate Dynamics in a Mediterranean Seagrass (Posidonia oceanica) Meadow
We measured monthly dissolved oxygen (DO) changes in situ benthic incubations from March 2001 to October 2002 in a Posidonia oceanica meadow and unvegetated sediments of Magalluf Bay (Mallorca Island, Spain) to determine gross primary production (GPP), community respiration (R), and net community production (NCP). From June 2001 to October 2002, we also measured fluxes of dissolved inorganic ca...
متن کاملExperimental evidence of reduced particle resuspension within a seagrass (
Dried leaf fragments of the Mediterranean seagrass Posidonia oceanica were used as tracer particles to test if seagrass leaf canopies reduce particle resuspension. Half Petri dishes containing a known mass of tracer particles were deployed for 24 h, five times during the summer period inside a 15-m deep P. oceanica meadow and on an adjacent sandy bottom devoid of vegetation. The loss of tracer ...
متن کاملThresholds of irradiance for seagrass Posidonia oceanica meadow metabolism
Meadows of the endemic seagrass Posidonia oceanica are threatened in the Mediterranean due to a general deterioration of the light environment that becomes critical when light irradiance is insufficient to meet the carbon requirements of the system. Here, we conduct a 3 wk, in situ shading experiment (8 levels plus controls) to determine the threshold of irradiance for balanced metabolism in a ...
متن کامل