The Uptake of I^(131) by the Biota of Fern Lake, Washington, in a Laboratory and a Field Experiment

Abstract

The distribution of I131 among the biota of Fern Lake, Washington, was compared in aquarium and field experiments. The samples for study in the laboratory were isolated in containers so that the water solution, and not food, was the major source of the radionuclide. The field experiment related the uptake of I131 by organisms isolated in containers to the accumulation by those with access to their usual sources of food. In the aquarium, the initial concentration of I131 was 8,000 times the average concentration calculated for the lake experiment. Maximum concentration factors ranged from 1.7 and 2.6 for the muscle of trout and crayfish, respectively, to 280 for the "thyroid" of trout, 380 for Nitella, and 600 for an amphipod. I131 was not detected in a number of samples collected from the lake, but accumulation factors were as high as 1,400 for Nitella clumps and 12,000 for the "thyroid" of trout. Young microcrustaceans, which are able to accumulate iodine directly from water, were an important source of I131 for trout.