The Distribution of trace metals and fauna in the firth of clyde in relation to the Disposal of Sewage Sludge

Abstract

SummaryTrace metals have been determined in the sediments, waters and fauna of a sewagesludge disposal area in the Firth of Clyde. Enhanced values of organic carbon and several metals were found in the sediments of the immediate deposit area. The results are discussed in relation to local background variations and compared with data from the Solway Firth. Trace-metal concentrations in the waters of the deposit area were higher than those from further off shore in the Clyde.Epifaunal species showed rather erratic variation in trace metal content, unrelated to total or readily extractable trace metals in the underlying sediment. The tracemetal content of demersal fish species was not significantly different from figures reported for elsewhere in the United Kingdom.The distributions of some in-faunal and epifaunal species in the area are described.It is concluded that the effects of sewage sludge disposal in this area are local, gross changes being limited to an area of about 20 km2 of sea-bed. However, little is known of the overall effects of toxic wastes particularly at threshold levels, and further monitoring is required.

Mercury pollution in the Ems estuary

“…High concentrations in the upper sediment layer were found only in the vicinity of Delfzijl {Table 2). Such a local distribution has also been reported elsewhere (Halcrow et al, 1973;Skei, 1978;Jones & Jordan, 1979}. In all these localities the hydrographical conditions allow for significant sedimentation of particulate matter contaminated by mercury.…”

“…When methodological inaccuracies in the estimation of the sedimentation are taken into account, the obtained results, showing the same order of magnitude, do not contradict the conclusion that the mercury-enriched top layers of the Cores 1-3 and 5, and the entire Core 4 sedimented in the period of high mercury discharges, i. e. 1960-1976. A similar agreement between the downward occurrence of enhanced mercury contents and the depth of deposition since the disposal and discharge of mercury-containing waste commenced was found in the Firth of Clyde {Halcrow et al & Thornton, 1973) and in Mobile Bay, Alaska (Lindberg & Harris, 1974).…”

Association of benthic macrofauna with habitat types and quality in the New York Bight

“…Capitella spp. are widely recognized as indicators of organic pollution (Halcrow et al 1973, Pearson & Rosenberg 1978 (Reid et al 1991) C. americanus, N. incisa and N. proxima (Pearson & Rosenberg 1978, Steimle 1985. On the other hand, the amphipod genus Ampelisca (Lee et al 1977, Sanders et al 1980, amphipods and crustaceans in general (Pearson & Rosenberg 1978), and total number of species in a community (Green & Vascotto 1978) are reported to be negatively affected by even low levels of habitat contamination.…”

Effects of zinc on the life-cycle, growth and reproduction of the marine amphipod Corophium volutator

“…Elevated zinc levels can also be due to natural causes, which are exacerbated by historic mining activities. Zinc concentrations in sewage sludge in the form dumped at sea in the UK range from 93 to 1660 pg g-' off Plymouth (Halcrow et al 1973) to 3980 pg g-' in the outer Thames Estuary (Norton et al 1981). In sediments receiving sewage sludge, the concentrations of zinc are known to reach up to 1200 pg g-', e.g.…”