Sediment trapping and stabilisation

conceptual diagram of sediment trapping and stabilisation process

 Suspended sediment
Due to their filtering ability, water often tends to leave estuarine wetlands clearer, with less suspended sediment. However, large floods may temporarily reverse this situation (Wolanski, 1995; Furukawa et al, 1997)
Surface water flow from land brings suspended sediment into estuarine wetlands (Wolanski, 1995; Furukawa et al, 1997)
Sediment from rivers and the sea is mixed in estuaries (Noble et al, 2005)
Intertidal vegetation creates eddies and slows down water flow (Furukawa et al, 1997)
Tidal currents, waves and biological activity can ause sediment resuspension (Noble et al, 2005)
Surface water flow leaves the intertidal salt flat, salt marsh and mangrove zone after depositing some of its remaining sediment load (Wolanski, 1995; Furukawa, et al, 1997)
Incoming tides bring suspended sediment into intertidal areas (Furukawa and Wolanski, 1996; Noble et al, 2005)
Slower flowing water deposits sediment (Furukawa et al, 1997)
Outflowing tides with lower tidal energy carry a reduced amount of sediment to sub-tidal areas, partly due to sediment trapping by intertidal vegetation (Mazda, 1995; Furukawa and Wolanski, 1996; Noble et al, 2005)
Roots, rhizomes and algal mats bind and hold sediment (Wolanski, 1995; Miller et al, 1996; Butler and Jernakoff, 1999)    

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References:

  1. Butler, A. & Jernakoff, P. 1999, Seagrass in Australia: Strategic Review and Development of an R&D Plan, CSIRO Publishing, Melbourne.
  2. Furukawa, K., Wolanski, E., Mueller, H., 1997, Currents and sediment transport in mangrove forests, Estuarine, Coastal and Shelf Science Vol. 44, no. 3, pp. 301-310.
  3. Furukawa, K., Wolanski, E., 1996, Sedimentation in Mangrove Forests, Mangroves and Salt Marshes, Volume 1(1) p3 - 10.
  4. Mazda, Y., Kanazawa, N., Wolanski, E., 1995, Tidal asymmetry in mangrove creeks, Hydrobiologia, Volume 295 (1-3) Pages 51 - 58.
  5. Miller, D. C., Geider, R.J., MacIntyre, H.L., 1996, Microphytobenthos: The Ecological Role of the "Secret Garden" of Unvegetated, Shallow-Water Marine Habitats. II. Role in Sediment Stability and Shallow-Water Food Webs, Estuaries, Vol. 19, No. 2, Part A: Selected Papers from the First Annual Marine and Estuarine Shallow Water Science and Management Conference (Jun., 1996), pp. 202-212.
  6. Noble, B., Bell, A., Verwey, P., Tilden, J., Fitzroy in focus: Coastal science for the Fitzroy region, Coastal CRC, Brisbane.
  7. Lynch, J.C., Meriwether, J.R., McKee, B.A., Vera-Herrara, F., Twilley, R.R., 1989, Recent accretion in mangrove ecosystems based on 137Cs and 210Pb, Estuaries 12, 284-299.
  8. Wolanski, E. Mazda, Y. and Ridd, P. 1992, Mangrove Hydrodynamics, Mangrove tropical ecosystems: coastal and estuarine studies, Ed. By A.I. Robertson and D.M. Alongi, p 43-62, American Geophysical Union, Washington D.C.
  9. Wolanski, E. 1995 Sediment transport in mangrove swamps, Hydrobiologia, Volume 295 (1-3) 51 - 58.

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