Long-term changes in strontium-90 concentrations within a freshwater predator-prey system |
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| Authors: | J R Beddington C A Mills †† F Beards ‡ M J Minski ‡ J N B Bell ‡ |
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| Institution: | Renewable Resources Assessment Group, Imperial College of Science and Technology, 8 Prince's Gardens, London SW7 1N A, U.K.;Institute of Freshwater Ecology, Windermere Laboratory, Ambleside, Cumbria LA22 0LP, U.K.;Reactor Centre, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, U.K. |
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| Abstract: | It proved possible to determine the levels of Sr-90 in the opercular bones of individual pike, Esox Iucius , and in pooled samples of bones from perch, Perca fluviatilis . Results from both species from Windermere demonstrated that Sr-90 levels rose from below the detection limits in the 1940s to a peak in the 1960s, followed by a decline in the subsequent two decades. This decline was slower than would have been expected from the decline in northern hemisphere Sr-90 fallout, indicating the likelihood of recycling within the environment. Sr-90 levels were consistently lower in pike than in perch, their main prey fish. Thus, there is no concentration of Sr-90 up this part of the aquatic food chain. Tracking Sr-90 in bones taken in successive years from ages 3 to 8 for a single cohort of pike showed that the quantity of Sr-90 was closely related to opercular bone (and hence fish) weight. No significant increase in Sr-90 concentration in the bone with increasing age was demonstrated. |
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| Keywords: | Esox lucius Perca fluviatilis operculum fallout food chain |
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