Estuaries turbidity maximum

With regards to solid phase, most of the estuaries are characterized by a "turbidity maximum". The fresh water flow generates an entrainment from the bottom water, the sea water which is entrained from the lower layer by this flow being compensated by a residual landward flow along the bottom. The river-borne particles which settle in this bottom layer are taken up by the residual landward current and trapped in the middle part of the estuary. This process greatly enhances the residence time of particles, especially in tidal estuaries. 

The estuaries chosen for the studies were the Gironde and Loire estuaries (France) both caracterized by relatively long flushing and residence times (Martin, Mouchel and Thomas, 1984) as well as by a well developped turbidity maximum. Their general characteristics have been described previously (Allen, 1972 Barbaroux, 1980 Elbaz-Poulichet et al., 1982, 1984). 

Columbia estuary, in the estuarine turbidity maximum. (Modified from Klinkhammer and McManus, 2001.)... 

The partitioning of trace metals between the dissolved and particulate fractions in estuaries can be affected by variability in river flow, tidal and wind energy, storms, coagulation, and flocculation in the estuarine turbidity maximum (ETM), resuspension events (of sediments and porewaters), and inputs from wetland and mudflat processes. 

Estuarine turbidity maximum a region where the suspended particulate matter (SPM) concentrations are considerably higher (10-100 times) than in adjacent river or coastal end-members in estuaries. 

Baross, J.A., Crump B., and Simenstad, C.A. (1994) Elevated microbial loop activities in the Columbia River estuarine turbidity maximum. In Changes in Fluxes in Estuaries Implications from Science to Management (Dyer, K.R., and Orth, R.J., eds.), pp. 459 -64, Olsen and Olsen, Fredensborg, Denmark. 

Brenon, I., and Le Hir, P. (1999) Modelling the turbidity maximum in the Seine estuary (France) Identification of formation processes. Estuar. Coastal Shelf Sci. 49, 525-544. 

Geyer, W.R. (1993) The importance of suppression of turbulence by stratification on the estuarine turbidity maximum. Estuaries 16, 113-125. 

Kistner, D.A., and Pettigrew, N.R. (2001) A variable turbidity maximum in the Kennebec Estuary, Maine. Estuaries 24, 680-687. 

Lin, J., and Kuo, A.Y. (2001) Secondary turbidity maximum in a partially mixed microtidal estuary. Estuaries 24, 707-720. 

Nichols, M.N. (1974) Development of the turbidity maximum in the Rappahannock estuary, Summary. Mem. Inst. Geol. Bassin d Aquitaine. 7, 19-25. 

North, E.W. and Houde, E.D. (2001) Retention of white perch and striped bass larvae biological-physical interactions in Chesapeake Bay estuarine turbidity maximum. Estuaries 24, 756-769. 

Uncles, C.M., Lavender, S.J., and Stephens, J.A. (2001) Remotely sensed observations of the turbidity maximum in the high turbid Humber Estuary, UK. Estuaries 24, 745-755. 

Uncles, R.L., Barton, M.L., and Stephens, J.A. (1994) Seasonal variability of fine-sediment concentrations in the turbidity maximum region of the Tamar Estuary. Estuar. Coastal Shelf Sci. 38, 19-39. 

Figure 9 Relationship between estuarine turbidity in NTU and distance from the mouth of St. Lucia Estuary, Natal, on a rising tide on 20 March 1981, showing a clear turbidity maximum 8-12 km from the estuary mouth for both near-bed (bottom) and surface (top) waters. (From Cyrus DP (1988) Turbidity and other physical factors in Natal estuarine systems. Part 1 selected estuaries. Journal of the Limnological Society of southern Africa 14(2) 60-71.)...

Mitchell SB, Lawler DM, West JR, and Couperthwaite JS (2003) Use of continuous turbidity sensor in the prediction of fine sediment transport in the turbidity maximum of the Trent Estuary, UK. Estuarine Coastal and Shelf Science 58 643-650. 

Dodson, J.J., Dauvin, J.C., Ingram, R.G., and D Anglejan, B. (1989) Abundance of larval rainbow smelt (Osmerus mordax) in relation to the maximum turbidity zone and associated macrozooplanktonic fauna of the middle St. Lawrence estuary. Estuaries 12, 66-81. 

Herman, P.M., and Heip, C.H.P. (1999) Biogeochemistry of the MAximum TURbidity zone of Estuaries (MATURE) some conclusions. J. Mar. Syst. 22, 89-104. 

Phenols derived from lignin degradation were used as markers to determine the origin of waters of the Seine estuary in France. Thus, fluvial run-off contains syringic, hydroxyben-zoic and vanillic phenols, whereas upstream penetrating marine waters contain cinnamic phenols derived from the estuarine herbs. In the maximum turbidity zone the vanillic acid (38) to vanillin (39) ratio increases due to aerobic degradation of lignin . ... 

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