Details
| Original language | English |
|---|---|
| Article number | 802343 |
| Journal | Frontiers in Marine Science |
| Volume | 9 |
| Publication status | Published - 29 Mar 2022 |
Abstract
Seagrasses represent an essential part of the coastal environment and are hence the target of many coastal restoration projects. Artificial seagrass (ASG) mats may facilitate seagrass growth, making them a captivating option for restoration projects. However, little is known about the forces occurring on mats deployed in marine environments and especially on how these forces are transmitted to the anchoring points. Here, we present a study of prototype biodegradable coconut-mesh mats as base layer for ASG meadows and investigate the forces that occur at the anchors. We test the performance of three mesh types under wave forcing using two different anchor configurations without ASG and subsequently test ASG mats of one mesh type under wave forcing and a 4-anchor configuration to assess the effect of the ASG on anchor loading as a function of incident orbital velocities. We found that the mat composition plays a more important role than the number of anchors in anchor load reduction. The anchor forces were 2–4 times higher at front anchors compared to rear anchors, relative to wave propagation direction, and were also considerably higher in that direction compared to the opposite direction. With ASG, the forces increased compared to the highest measured forces without ASG. The forces on the anchors were almost fully dominated by the drag on the ASG based on material properties, ASG reconfiguration and flow conditions. We derive a relation between horizontal orbital velocities and expected forcing on the anchor based on ASG properties and the corresponding area of each anchor and discuss relevant criteria for the design of ASG mats. This should help to assess the loading on anchors deployed for restoration under specific site conditions and chosen materials.
Keywords
- anchors, artificial seagrass, coir, ecosystem restoration, geotextiles, wave forcing
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Oceanography
- Environmental Science(all)
- Global and Planetary Change
- Agricultural and Biological Sciences(all)
- Aquatic Science
- Environmental Science(all)
- Water Science and Technology
- Environmental Science(all)
- Environmental Science (miscellaneous)
- Engineering(all)
- Ocean Engineering
Sustainable Development Goals
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In: Frontiers in Marine Science, Vol. 9, 802343, 29.03.2022.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Anchor Forces on Coir-Based Artificial Seagrass Mats
T2 - Dependence on Wave Dynamics and Their Potential Use in Seagrass Restoration
AU - Villanueva, Raúl
AU - Paul, Maike
AU - Schlurmann, Torsten
N1 - Funding Information: This study was part of the collaborative project “SeaArt – Long term establishment of SEAgrass ecosystems through biodegradable ARTificial meadows,” funded by the Niedersächsisches Vorab and Ministry of Science and Culture (MWK) of the Federal state of Lower Saxony under Grant No. ZN3187.
PY - 2022/3/29
Y1 - 2022/3/29
N2 - Seagrasses represent an essential part of the coastal environment and are hence the target of many coastal restoration projects. Artificial seagrass (ASG) mats may facilitate seagrass growth, making them a captivating option for restoration projects. However, little is known about the forces occurring on mats deployed in marine environments and especially on how these forces are transmitted to the anchoring points. Here, we present a study of prototype biodegradable coconut-mesh mats as base layer for ASG meadows and investigate the forces that occur at the anchors. We test the performance of three mesh types under wave forcing using two different anchor configurations without ASG and subsequently test ASG mats of one mesh type under wave forcing and a 4-anchor configuration to assess the effect of the ASG on anchor loading as a function of incident orbital velocities. We found that the mat composition plays a more important role than the number of anchors in anchor load reduction. The anchor forces were 2–4 times higher at front anchors compared to rear anchors, relative to wave propagation direction, and were also considerably higher in that direction compared to the opposite direction. With ASG, the forces increased compared to the highest measured forces without ASG. The forces on the anchors were almost fully dominated by the drag on the ASG based on material properties, ASG reconfiguration and flow conditions. We derive a relation between horizontal orbital velocities and expected forcing on the anchor based on ASG properties and the corresponding area of each anchor and discuss relevant criteria for the design of ASG mats. This should help to assess the loading on anchors deployed for restoration under specific site conditions and chosen materials.
AB - Seagrasses represent an essential part of the coastal environment and are hence the target of many coastal restoration projects. Artificial seagrass (ASG) mats may facilitate seagrass growth, making them a captivating option for restoration projects. However, little is known about the forces occurring on mats deployed in marine environments and especially on how these forces are transmitted to the anchoring points. Here, we present a study of prototype biodegradable coconut-mesh mats as base layer for ASG meadows and investigate the forces that occur at the anchors. We test the performance of three mesh types under wave forcing using two different anchor configurations without ASG and subsequently test ASG mats of one mesh type under wave forcing and a 4-anchor configuration to assess the effect of the ASG on anchor loading as a function of incident orbital velocities. We found that the mat composition plays a more important role than the number of anchors in anchor load reduction. The anchor forces were 2–4 times higher at front anchors compared to rear anchors, relative to wave propagation direction, and were also considerably higher in that direction compared to the opposite direction. With ASG, the forces increased compared to the highest measured forces without ASG. The forces on the anchors were almost fully dominated by the drag on the ASG based on material properties, ASG reconfiguration and flow conditions. We derive a relation between horizontal orbital velocities and expected forcing on the anchor based on ASG properties and the corresponding area of each anchor and discuss relevant criteria for the design of ASG mats. This should help to assess the loading on anchors deployed for restoration under specific site conditions and chosen materials.
KW - anchors
KW - artificial seagrass
KW - coir
KW - ecosystem restoration
KW - geotextiles
KW - wave forcing
UR - http://www.scopus.com/inward/record.url?scp=85128404291&partnerID=8YFLogxK
U2 - 10.3389/fmars.2022.802343
DO - 10.3389/fmars.2022.802343
M3 - Article
AN - SCOPUS:85128404291
VL - 9
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
SN - 2296-7745
M1 - 802343
ER -