818 RADIONUCLIDES IN MARINE PROTEIN CONCENTRATES Table 3. Trace element concentrations in fish protein concentrates Sample Menhaden (Breveortia iyrannits) Menhaden (Brevoortia hrannus) Menhaden (Brevoortia lyrannus) Menhaden (Bretvoortia tyrannus) Ocean Pout ( Afacra zoarces americanus) Alewife (Alasa pseudo harengus) Gulf Menhaden (Bretoortia patronus) Anchovy (Engrautis mordax) Atlantic herring (Clupea harengus harengits) Location also ratios measured Trace element concentrations (ug/g dry wt. ppm) —— ——— Pb Ag Cd Gu Co Fe Yn Mn Chesapeake Bay june, 69 0.8 1.3 1.0 54 4.6 346 124 Chesapeake Bay June, 69 1.0 1.3 1.0 66 16 492 128 33 Chesapeake jay June, 69 1.0 10 0.8 5.6 1.1 614 131 64 Chesapeake June, 69 1.0 1] 0.8 7.5 1.5 403 126 53 Mass. Coast Jan., 69 0.3 1.9 Ll 6.5 63 254 93 9 Lake Michigan April, 69 0.7 1.0 1.0 66 1.7 123 170 2) Miss. Coast May, 69 2.3 1.5 1.0 53 1.6 860 142 64 South California Coast Mass. Coast Jan., 69 8.2 1500 2.30 11.7 1.1 373 143 12 Nov., 68 0.5 0.9 0.6 8.4 1.2 116-110 10 Bay are in fam agreement with this ratio. has Catch date the 7!8Po/?©Pb in zooplankton, Shannon activity and reports a mcan value of 12. ‘Lhe pooled stomach contents of our anchovy specimens had a mean 7!°Po/ “0P}) activity ratio of approximately 12, again in good agreement with Shannon’s findings, if we assume the stomach contents of the anchovy represent zooplankton residues. The same high #Po/719Pb ratio was obscrved lor the internal organs of the saury, ‘The stomach contents, however, showed a marked in- crease in this ratio, as a result of higher “Po concentrations. Unfortunately, identification of their stomach contents was not possible and we therefore cannot assign this higher rauo to a parucular marine entity. ‘he data in ‘Pable 2 suggests that, at least in the case of Pb, "Pb and 728Po, evisccration of the fish prior to processing would aid in reducing the concentrations of these entitics in the final 4] product. It is not possible to assign an absolute value for the anticipated reduction, for the weight fraction which each organ contributes to the total fish weight is only poorly known for different fish specics.4) TRACE ELEMENT CONCENTRATIONS Table 3 lists the concentrations of trace elements which were measured in these FPC products. The numberof trace clements which are included is not exhaustive, and clearly there are linportant clements missing, lor example, Se and As concentrations would have been informative, as would the concentrations of Mo, ‘Ti, Si, B and Ni. We chose the trace clements shown in ‘Vable 3 because several are considered toxic in moderate amounts (Pb, Ag, Cd, Cu) while others, in small amounts, arc essenual to good nutrition (Co, Fe, Zn, Mn)."”? The high concentration of Pb in the anchovy ¥PC is consistent with the findings shown in pop REC" coe