Severn Estuary

As the result of a mix-up at a distribution center, two tank track drivers received each other s papers. One of the trucks carried a load of sodium chlorite solution, and the other carried epichlorohydrin. The chlorite truck went to the customer who was expecting epichlorohydrin and was off-loaded into a tank that already contained some epichlorohydrin. The result was an explosion and a serious fire fumes and smoke led to the closure of the bridges over the Severn Estuary. UK [12, 13]. 

Butterworth, J., P. Lester, and G. Nickless. 1972. Distribution of heavy metals in the Severn Estuary. Mar. Pollut. Bull. 3 72-74. 

Hardisty, M.W., S. Kartar, and M. Sainsbury. 1974. Dietary habits and heavy metal concentrations in fish from the Severn Estuary and Bristol Channel. Mar. Pollut. Bull. 5 61-63. 

Rotchell, J.M., Bird, D.J., Newton, L.C. (1999). Seasonal variation in ethoxyresorufin O-de-ethylase (EROD) activity in European eels Anguilla anguilla and flounders Pleuronectes flesus from the Severn estuary and Bristol Channel. Marine Ecology Progress Series, 190 263-270. 

Ruddock, P.J., Bird, D.J., McCalley, D.V. (2002). Bile metabolites of polycyclic hydrocarbons in three species of flsh from the Severn estuary. Ecotoxicology and Environmental Safety, 51 97-105. 

Mantoura, R.F.C. and Woodward, E.M.S., 1983. Conservative behaviour of riverine dissolved organic carbon in the Severn estuary chemical and geochemical... 

Harris, P.T., and Collins, M.B. (1985) Bedform distributions and sediment transport paths in the Bristol Channel and Severn Estuary, UK. Mar. Geol. 62, 153-166. 

Killops S. D. and Howell V. J. (1988) Sources and distribution of hydrocarbons in Bridgewater Bay (Severn Estuary, UK) intertidal surface sediments. Estuar. Coast. Shelf Sci. 27, 237-261. 

Anthropogenic inputs to intertidal environments are often direct, through point-source waste disposal, but they are also indirect, from riverine, marine and/or atmospheric sources. Trace metals are partitioned between each component of the intertidal sediment-water system they are found in solution ( bulk water or interstitial water) and associated with suspended and deposited sediments. This chapter is concerned with the biogeochemistry of trace metals in deposited intertidal sediments. Two main sections follow in the first, an overview of surface sediments and sediment depth profiles is presented, and in the second, a case study is given of the historic record of Zn from saltmarsh sediments in the Severn Estuary, UK. 

Since it is well known that sediment grain-size and organic content influence trace metal concentrations, it would be expected that temporal variability in trace metal concentrations would also be found. This is indeed the case (French, 1993a), but additional controls appear to also exert an influence zinc exhibits a temporal variability even after grain-size correction in Severn Estuary sediments (French, 1993b), probably reflecting... 

The record of zinc pollution in a sediment depth profile at Tites Point, Severn Estuary, UK a case study... 

Figure 2.5 The Severn Estuary and Tites Point setting in southwest England a schematic vertical profile of the saltmarsh cliff (after Rae Allen, 1993).

Early work on trace metals in sediment depth profiles in the Severn Estuary provided an overview of trace metal concentrations in marsh sediments, in order to establish a chemostratigraphy (Allen, 1987c Allen Rae, 1987 Allen, 1988). Later work (Allen et al, 1990) provided a preliminary investigation of the post-depositional behaviour of Cu, Zn and Pb at one location (Tites Point). Subsequent intensive sampling of an adjacent profile has allowed a more detailed appreciation of trace metal concentrations and behaviour. 

Figure 2.6 Variation in the saltmarsh sediment concentration of total zinc with depth in a dated and archaeological evidence) profile from Tites Point, Severn Estuary, UK.

Figure 2.7 Variation in the saltmarsh sediment concentration of zinc with depth in four fractions, defined according to the sequential extraction scheme of Tessier, Campbell Bisson (1979) as F2, carbonate F3, Fe and Mn oxide and hydroxide F4, organic F5, residual. The location of the profile is Tites Point, Severn Estuary, UK.

Allen, J.R.L. (1985b) Intertidal drainage and mass-movement processes in the Severn Estuary rills and creeks (pills). Journal of the Geological Society, London 142, 849-61. 

Allen, J.R.L. (1987a) Dimlington Stadial (late Devensian) ice-wedge casts and involutions in the Severn Estuary, southwest Britain. Geological Journal 22, 109-18. 

Allen J.R.L. (1987b) Late Flandrian shoreline oscillations in the Severn Estuary the Rumney Formation at its typesite (Cardiff area). Philosophical Transactions of the Royal Society, B 315, 157-84. 

Allen, J.R.L. (1987c) Towards a quantitative chemostratigraphic model for the sediments of late Flandrian age in the Severn Estuary, U.K. Sedimentary Geology 53,73-100. 

Allen, J.R.L. (1987d) Reworking of muddy intertidal sediments in the Severn Estuary, Southwestern U.K. - a preliminary study. Sedimentary Geology 50, 1-23. 

Allen, J.R.L. (1990a) The Severn Estuary in southwest Britain its retreat under marine transgression, and fine-sediment regime. Sedimentary Geology 96, 13-28. 

Allen, J.R.L. (1991b) Fine sediment and its sources, Severn Estuary and inner Bristol Channel, southwest Britain. Sedimentary Geology 75, 57-65. 

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