The uptake, accumulation and retention of 137-caesium by salmonid fish in fresh water
The Chernobyl disaster on 26ih April 1986, caused contamination over much of the U.K. with radiocaesium, principally via rainfall in upland areas such as N. Wales and S.W. Scotland. 137-Caesium was of particular concern in the freshwater environment as it has a long physical half-life (30yr) and pre...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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University of Stirling
1992
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| Online Access: | http://hdl.handle.net/1893/29414 http://dspace.stir.ac.uk/bitstream/1893/29414/1/Morgan.pdf |
| Summary: | The Chernobyl disaster on 26ih April 1986, caused contamination over much of the U.K. with radiocaesium, principally via rainfall in upland areas such as N. Wales and S.W. Scotland. 137-Caesium was of particular concern in the freshwater environment as it has a long physical half-life (30yr) and previous studies had shown that 137-caesium accumulated in freshwater animals and that the levels of accumulation increased with trophic level up the food chain. This thesis presents the results of studies on the uptake, accumulation and retention of 137-caesium in salmonid fish in fresh water. A number of previous studies both m vitro and in vivo have observed biochemical similarities of caesium to potassium. The uptake of 137-caesium and 86- rubidium (as a tracer for potassium) by erythrocytes of the rainbow trout (Oncorhynchus mykiss Walbaum) was studied. The total caesium influx was much smaller than that of potassium ( 14.4 and 796.0nmoles min ' ml ' packed cells respectively), at an external concentration of .3mM. Potassium influx was significantly inhibited by caesium and vice versa, at concentrations >0.1 mM. The results indicated that caesium behaved as potassium in a qualitative but not quantative manner. This conclusion, together with evidence from the literature, was used to justify biochemical compansons of the two elements later in the thesis. The accumulation of 137-caesium was studied in the early stages of development of Atlantic salmon {Saimo salar L.) and brown trout {.Salmo trutta L.). The accumulation of the isotope in the eggs of brown trout was relatively small until a few days prior to hatching, when the 137-caesium concentration factor (C F.) increased rapidly. The accumulation of 137-caesium in juveniles of Atlantic salmon and brown trout followed a first order rate equation, ie. the rate of increase of accumulation decreased until a constant, equilibrium C.F. was reached. 137-Caesium accumulated several times above the concentration in water, reaching equilibrium after 4-6 months at C.F.s of ... |
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