Number of samples. (b) Floodgate iro (a The + value is 1 o counting error. When the counting error is 7100%, the concentration is reported as <2 0. 26,82 0,5 0.04 + 0.02 1,07 4 0.08 59 + 31—106 + 65 286 + 288 Franklin (3) (D) Nm id (soft parts) Crayfish Rip Rap Bridge 0.8 km S. Chautauqua % Wt D Wet Wt 23.0—-24.5] <0.37 0.35 + 0.20~0,44 + 0,20) 0.12 +06.12 0.53 + 0.28 0.04 40.04 0.14+ 0.03 2368, 25.5 + 1.5-37.2 41.7] 35,241.5 70.2 3.5+41.0 385/239: 2400 9 (a wa 522 Rip Rap Bridge Table 3 presents data for miscellaneous aquatic organisms. Again, 239, 240py concentrations are fairly simllar upstream and downstream from Mound Laboratory. The clam shells have not been analyzed, but the soft parts have very iow levels of plutonium, The 239,240py concentrations in crayfish reported here are similar to published results for crayfish from Lake Michigan (Yaguchi et al., 1973). The concentration of Pu in a whole frog collected at Floodgate, downstream from Mound Laboratory, is in the range of values found in carp bodies collected downstream. As expected, crayfish show a iGlams possibility would explain the relatively low 238p.y activities of their gastrointestinal tract and contents, Sample Fowler, 1974). The 238py concentrations in gastrointestinal tracts for carp collected at the Power Plant site are much lower than those from other downstream sites. These fish were captured in deep water with a boomshocker and were much larger than those collected by other methods at different sampling sites. Because the Power Plant site is less than 2 km below Mound Laboratory, it is possible that either these fish moved into the area from upstream shortly before capture, or the difference in size and feeding habits caused less sediment to be present in their gut. Either Pu activities (Ci/g dry wt) fers across intestinal walls into body tissues; mest of it is eliminated in the feces (Emery et al., 1974), This lack of transfer across the gut wall is confirmed in other plutonium distribution studies (Bowen, 1974; Adams and 239,240 porportion of high activity sediment in the gut at capture, It 1s apparent from the data in Table 2 that little of the plutonium taken into the gut trans- Pu and material, Since algal and sediment activities (Wayman etal., 1974; Volchok, 1975} are much higher below Mound Laboratory, the variability in 8pu concentrations generally indicate the volume of material and relative 238 Carp with gastrointestinal tracts removed show only a slight increase in 238py downstream from Mound while activities in gut tissue and contents are more variable and much higher (Table 2). Analysis of stomach contents of carp from the Great Miami River indicate plant and algal detritus along with varying amounts of sediment comprise the major proportion of gut Table 3, studies by other workers show food and habitat effects on plutonium concentrations in fish (Waller et al., 1973; Noshkin, 1972; Emery et al,, 1974). in miscellaneous aquatic organisms. The Power Plant station is downstream of Mound Laboratory within 0.5 km of our Chautauqua sampling site. The concentrations of 239,240py in different species from all sites are quite similar and fall within the range of values reported from other studies of freshwater and marine fish (Waller et al., 1973; Bowen, 1974; Livingston and Bowen, 1975; Noshkin, 1972; Miettinen, 1976). The elevated concentrations of 238py below Mound also show little variance between different species. Since shad are typically filter feeders, carp and goldfish bottom feeders, and minnows selective feeders (Lagler, 1952), feeding preferences appear to have little effect on plutonium concentrations. However, this apparent consistancy may be a function of the small sample size, as more detailed 239,240, shows slightly elevated levels of 238py, possibly due to contamination during analysis.