Fate and effects of cadmium in an experimental marine ecosystem

Abstract

Two recirculated marine seawater systems (capacities: 150 and 300 1) were used for the study on cadmium accumulation of biological filter sludge, by the mussel Mytilus edulis and the plaice Pleuronectes platessa for a period of up to 300 days. In the contaminated system Cd concentrations varied from 2.5 to 7.0 #g/1 with a mean of 4.6 + 1.15 #g/1 (control: 1.04 + 0.46 #g/l). Accumulation of Cd by the filter sludge from the control system as well as from the contaminated system was significant. Mean concentrations of control and contaminated sludge over the experimental period were 2.01+0.86 ng Cd/mg dry wt and 9.98+3.55 ng Cd/mg dry wt respectively. Accumulation of Cd by M. edulis both in the control and in the contaminated system was considerable. After 163 days of exposure the whole body burden of mussels rose from 0.3 ng Cd/mg dry wt to around 10 ng Cd/mg dry wt in the controls and to 70 ng Cd/mg dry wt in the contaminated systems. Accumulation of Cd by P. platessa was analysed in backbone, fins, gills, liver, muscle (fillet), otolith and skin (dorsal and ventral) over a period of 280 days. Elevated Cd contents of livers from control specimens were noticed after 200 days and reached 1.75 ng Cd/mg dry wt in liver. There was considerable accumulation in the liver (maximum values: 3.0 ng Cd/mg dry wt) and gills (6.0 ng Cd,'mg dry wt) of specimens from the contaminated system, Cd contents of plaice exposed for identical periods of time were very variable. Growth of plaice living in the contaminated system was at times significantly slower than that of the control group. Of the three biological objects tested -filter sludge, M. edulis, P. platessa -the mussel seemed to be the most sensitive indicator of elevated Cd-concentrations, while the reaction of the plaice was slow and less distinct.

Ascorbic acid status of mullet, Mugil cephalus Linn., exposed to cadmium

“…Many of these signs of ascorbic acid deficiency are also characteristic of cadmium poisoning. The growth rate decreases, anaemia and haemorrhages develop, fin regeneration is delayed, and the skeleton becomes deformed in cadmium intoxicated fish (Cearley & Coleman, 1974;Larsson, 1975;Weis & Weis, 1976;Westernhagen et al, 1978Westernhagen et al, , 1980. Hepatic cytochrome P-450 levels fall in rats exposed to cadmium (Schnell et al, 1979) and also in scorbutic guinea pigs (Omaye & Turnbull, 1979).…”

“…fBattelle New England Laboratories, 397 Washington St., Duxbury, MA 02332, U.S.A. I83 0022-1 112/82/020183+14 $02.00/0 signs of cadmium poisoning are also found in fish. Decreased growth rates (Westernhagen et al, 1978), lowered blood iron and calcium concentrations (Larsson, 1975;Roch & Maly, 1979) and testicular injury (Sangalang & O'Halloran, 1972) in fish have been reported after cadmium exposure. However, there is little published work on the interrelationship between ascorbic acid status and cadmium toxicity in teleosts.…”

Cadmium levels in oystercatcher Haematopus ostralegus from the German Wadden Sea

“…Of all these, mussels are known to be the most sensitive indicators to elevated concentrations of heavy metals, particularly cadmium. Within the food-chain mussels, and to a lesser extent cockles, accumulate high levels or certain heavy metals (von Westernhagen et al 1978, Buchwald et al 1985. These and other diets of waders and shorebirds are contaminated with heavy metals (Packer et al 1970, Evans & Moon 1981, Zunk 1988.…”

Physiological responses of estuarine animals to cadmium pollution

“…In vertebrates and invertebrates, effects of Cd on growth (Stebbing, 1976~ Paffenh6fer, 1978yon Westernhagen et al, 1978;Stebbing & Hiby, 1979), embryo and larval development (Calabrese et al, 1973;Mirkes et al, 1978;Reish &Carr, 1978;Alderdice et al, 1979;KI6ckner, 1979;Lehnberg & Theede, 1979), and the alteration of various physiological functions (e. g. osmoregulation, excretion, respiration) (MacInnes & Thurberg, 1973;Thurberg et al, 1973;Dawson et al, 1977;Thurberg et al, 1977) and behaviour (Martin et al, 1975;Eldon & Kristoffersson, 1978) have been observed.…”