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Estuaries and Coasts

, Volume 41, Issue 3, pp 724–733 | Cite as

Particle Retention in a Submerged Meadow and Its Variation Near the Leading Edge

  • Elizabeth FollettEmail author
  • Heidi Nepf
Article
  • 254 Downloads

Abstract

The retention of particles within meadows of submerged aquatic vegetation impacts the fate of organic matter, pollen, and larvae. Because flow conditions near the leading edge differ from those over the bulk of the canopy, particle retention is likely to differ as well. In particular, near the leading edge of a wide meadow, flow deceleration generates a vertical updraft, which impacts particle fate. In the fully developed region of the meadow, shear layer vortices at the top of the meadow may also influence particle fate. In this study, the retention of particles was measured along the length of a 10-m model meadow (height h = 0.1 m) and was connected to the evolving flow field. Two particle sizes, with settling velocity w s50 = 0.00075 , 0.018 m s−1, were released at two heights within the model meadow \( \left(\frac{Z_{rel}}{h}=0.31,0.81\right). \) The retention of particles was measured using microscope slides distributed along the flume bed. Retention increased with distance from the leading edge, associated with the decrease in vertical updraft. Retention was also greater for the particles with higher settling velocity. In the fully developed region of the meadow, particle retention was lower for particles influenced by the shear layer vortices at the top of the meadow (\( \frac{Z_{rel}}{h}=0.81 \)).

Keywords

Particle transport Leading edge Capture Initial adjustment region Velocity ratio 

Notes

Acknowledgements

This material is based upon work supported by the National Science Foundation under Grant No. AGS-1005480. Any opinions, findings, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

References

  1. Agawin, N.S.R., and G.M. Duarte. 2002. Evidence of direct particle trapping by a tropical seagrass meadow. Estuaries and Coasts 25: 1205–1209.CrossRefGoogle Scholar
  2. Belcher, S.E., N. Jerram, and J.C.R. Hunt. 2003. Adjustment of a turbulent boundary layer to a canopy of roughness elements. Journal of Fluid Mechanics 488: 369–398.CrossRefGoogle Scholar
  3. Chen, Z., A. Ortiz, L. Zong, and H. Nepf. 2012. The wake structure behind a porous obstruction and its implications for deposition near a finite patch of emergent vegetation. Water Resources Research 48: W09517. doi: 10.1029/2012WR012224.Google Scholar
  4. Chen, Z., C. Jiang, and H. Nepf. 2013. Flow adjustment at the leading edge of a submerged aquatic canopy. Water Resources Research 49: 5537–5551. doi: 10.1002/wrcr.20403.CrossRefGoogle Scholar
  5. Cotton, J.A., G. Wharton, J.A.B. Bass, C.M. Heppell, and R.S. Wotton. 2006. The effects of seasonal changes to in-stream vegetation cover on patterns of flow and accumulation of sediment. Geomorphology 77: 320–334.CrossRefGoogle Scholar
  6. Denn, M.M. 1980. Process Fluid Mechanics. Upper Saddle River, NJ: Prentice Hall.Google Scholar
  7. Folkard, A. 2005. Hydrodynamics of model Posidonia oceanica patches in shallow water. Limnology and Oceanography 50: 1592–1600.CrossRefGoogle Scholar
  8. Folkard, A. 2011. Flow regimes in gaps within stands of flexible vegetation: laboratory flume simulations. Environmental Fluid Mechanics 11: 289–306.CrossRefGoogle Scholar
  9. Fonseca, M. 1998. Exploring the basis of pattern expression in seagrass landscapes. University of California - Berkeley, Ph.D. thesis.Google Scholar
  10. Gacia, E., and C.M. Duarte. 2001. Sediment retention by a Mediterranean Posidonia oceanica meadow: the balance between deposition and resuspension. Estuarine, Coastal, and Shelf Science 52: 505–514.CrossRefGoogle Scholar
  11. Gacia, E., T.C. Granata, and C.M. Duarte. 1999. An approach to the measurement of particle flux and sediment retention within seagrass (Posidonia oceanica) meadows. Aquatic Botany 65: 255–268.CrossRefGoogle Scholar
  12. Ghisalberti, M. 2009. Obstructed shear flows: similarities across systems and scales. Journal of Fluid Mechanics 641: 51–6.Google Scholar
  13. Ghisalberti, M., and H. Nepf. 2002. Mixing layers and coherent structures in vegetated aquatic flows. Journal of Geophysical Research 107: 3011.CrossRefGoogle Scholar
  14. Ghisalberti, M., and H. Nepf. 2004. The limited growth of vegetated shear layers. Water Resources Research 40: W07502. doi: 10.1029/2003WR002776.CrossRefGoogle Scholar
  15. Ghisalberti, M., and H. Nepf. 2006. The structure of the shear layer in flows over rigid and flexible canopies. Environmental Fluid Mechanics 6 (3): 277–301.Google Scholar
  16. Green, E.P., and F.T. Short. 2003. World atlas of seagrasses. Oakland: University of California Press.Google Scholar
  17. Gurnell, A.M., G.E. Petts, D.M. Hannah, B.P.G. Smith, P.J. Edwards, J. Kollmann, J.V. Ward, and K. Tockner. 2001. Riparian vegetation and island formation along the gravel-bed Fiume Tagliamento, Italy. Earth Surface Processes and Landforms 26: 31–62.CrossRefGoogle Scholar
  18. Hughes, A.R., and J.J. Stachowicz. 2004. Genetic diversity enhances the resistance of a seagrass ecosystem to disturbance. Proceedings of the National Academy of Sciences 101: 8998–9002.CrossRefGoogle Scholar
  19. Irvine, M., B. Gardiner, and M. Hill. 1997. The evolution of turbulence across a forest edge. Boundary Layer Meteorology 84: 467–496.CrossRefGoogle Scholar
  20. Lamb, J.B., J.A.J.M. van de Water, D.G. Bourne, C. Altier, M.Y. Hein, E.A. Fiorenza, N. Abu, J. Jompa, and C.D. Harvell. 2017. Seagrass ecosystems reduce exposure to bacterial pathogens of humans, fishes, and invertebrates. Science 355: 731–733.CrossRefGoogle Scholar
  21. Lawson, S.E., K.J. McGlatherty, and P.L. Wiberg. 2012. Enhancement of sediment suspension and nutrient flux by benthic macrophytes at low biomass. Marine Ecology Progress Series 448: 259–270.CrossRefGoogle Scholar
  22. Liu, C., and H. Nepf. 2016. Sediment deposition within and around a finite patch of model vegetation over a range of channel velocity. Water Resources Research 51 (1): 600–612. doi: 10.1002/2015WR018249.CrossRefGoogle Scholar
  23. Lowe, R.J., J.R. Koseff and S.G. Monismith. 2005. Oscillatory flow through submerged canopies: 1. Velocity structure. Journal of Geophysical Research 110: C10016.Google Scholar
  24. Luhar, M., S. Coutu, E. Infantes, S. Fox, and H. Nepf. 2010. Wave-induced velocities inside a model seagrass bed. Journal of Geophysical Research 115: C12005.Google Scholar
  25. Luhar, M., J. Rominger, and H. Nepf. 2008. Interaction between flow, transport, and vegetation spatial structure. Environmental Fluid Mechanics 8: 423–439.CrossRefGoogle Scholar
  26. Marbà, N., A. Arias-Ortiz, P. Masqué, G.A. Kendrick, I. Mazarrasa, G.R. Bastyan, J. Garcia-Orellana, and C.M. Duarte. 2015. Impact of seagrass loss and subsequent revegetation on carbon sequestration and stocks. Journal of Ecology 103: 296–302.CrossRefGoogle Scholar
  27. McKone, K. 2009. Light available to the seagrass Zostera marina when exposed to currents and waves. University of Maryland, Ph.D. thesis.Google Scholar
  28. Moore, K.A. 2004. Influence of seagrasses on water quality in shallow regions of the lower Chesapeake Bay. Journal of Coastal Research 20: 162–178.CrossRefGoogle Scholar
  29. Morse, A., B. Gardiner, and B. Marshall. 2002. Mechanisms controlling turbulence development across a forest edge. Boundary Layer Meteorology 103: 227–251.CrossRefGoogle Scholar
  30. Nepf, H., and E.R. Vivoni. 2000. Flow structure in depth-limited, vegetated flow. Journal of Geophysical Research 105: 28547–28557.CrossRefGoogle Scholar
  31. Nepf, H., M. Ghisalberti, B. White, and E. Murphy. 2007. Retention time and dispersion associated with submerged aquatic canopies. Water Resources Research 43: W04422.CrossRefGoogle Scholar
  32. Ortiz, A.C., A. Ashton, and H. Nepf. 2013. Mean and turbulent velocity fields near rigid and flexible plants and the implications for deposition. Journal of Geophysical Research: Earth Surface 118: 2585–2599.Google Scholar
  33. Pan, Y., M. Chamecki, S.A. Isard, and H. Nepf. 2015. Dispersion of particles released at the leading edge of a crop canopy. Agricultural and Forest Meteorology 211-212: 37–47.CrossRefGoogle Scholar
  34. Raupach, M.R., J.J. Finnigan, and Y. Brunet. 1996. Coherent eddies and turbulence in vegetation canopies: the mixing-layer analogy. Boundary-Layer Meteorology 1970-1995: 351–382.CrossRefGoogle Scholar
  35. Sand-Jensen, K. 1998. Influence of submerged macrophytes on sediment composition and near-bed flow in lowland streams. Freshwater Biology 39: 663–679.CrossRefGoogle Scholar
  36. Tanaka, N., and J. Yagisawa. 2010. Flow structures and sedimentation characteristics around clump-type vegetation. Journal of Hydro-Environment Research 4: 15–25. doi: 10.1016/j.jher.2009.11.002.CrossRefGoogle Scholar
  37. Terrados, J., and C.M. Duarte. 2000. Experimental evidence of reduced particle resuspension within a seagrass (Posidonia oceanica) meadow. Journal of Experimental Marine Biology and Ecology 243: 45–53.CrossRefGoogle Scholar
  38. van Katwijk, M., A. Thorhaug, M. Núria, R. Orth, C. Duarte, G. Kendrick, et al. 2016. Global analysis of seagrass restoration: the importance of large-scale planting. Journal of Applied Ecology 53: 567–578.CrossRefGoogle Scholar
  39. van Katwijk, M.M., A.R. Bos, D.C.R. Hermus, and W. Suykerbuyk. 2010. Sediment modification by seagrass beds: muddification and sandification induced by plant cover and environmental conditions. Estuarine, Coastal and Shelf Science 89: 175–181.CrossRefGoogle Scholar
  40. Ward, L.G., W.M. Kemp, and W.R. Boynton. 1984. The influence of waves and seagrass communities on suspended particulates in an estuarine embayment. Marine Geology 59: 85–103.CrossRefGoogle Scholar
  41. Waycott, M., C. Duarte, T. Carruthers, R. Orth, W. Dennison, S. Olyarnik, A. Calladine, J. Fourqurean, K. Heck, A.R. Hughes, G. Kendrick, W.J. Kenworthy, F. Short, and S. Williams. 2009. Accelerating loss of seagrasses across the globe threatens ecosystems. Proceedings of the National Academy of Sciences 106: 12377–12381.CrossRefGoogle Scholar
  42. Zong, L., and H. Nepf. 2010. Flow and deposition in and around a finite patch of vegetation. Geomorphology 116: 363–372.CrossRefGoogle Scholar

Copyright information

© Coastal and Estuarine Research Federation 2017

Authors and Affiliations

  1. 1.Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeUSA

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