1. Uptake of Dietary PCBs by Rainbow Trout Robert F. Carline and Patrick M. Barry Penn. Coop. Fish & Wildlife Res. Unit U.S.G.S. and Penn State University H. George Ketola U.S.G.S Tunison Lab. Aquatic Science

2. Background 1998 PCBs discovered in PA state trout hatcheries 1999 PCB concentrations exceed state’s consumption advisory limits PCB concentrations varied among hatcheries

3. Background 1999 Low concentrations of PCBs in fish feeds Feeds meet FDA standard, <200 ppb

4. Objectives 1. What is the relation between concentrations of PCBs in fish feed and concentrations in trout fillets?

5. Objectives 2. Of the PCBs consumed by trout, what proportion is assimilated ?

6. Objectives 3. If PCBs are present in hatchery supply water, what are the relative contributions of PCBs from the water and from the feed to the total found in trout?

7. Feed Formulations (*Aroclor 1260 added) DietFish MealMenhaden Oil PCB (ppb) 1HerringDistilled69 2MenhadenFiltered126 3*3*MenhadenFiltered220 4*4*MenhadenFiltered280

11. Sampling PCBs in water Semi-permeable membrane device (SPMD) Flattened polyethylene tubing 91 cm long by 2.5 cm wide 0.9 grams of triolein (purified lipid)

13. Experiments 6-month trial: 4 diets 3-week assimilation trial: 4 diets

14. 6-Month Trial 4 diets 3 tanks of trout per diet Monthly sampling –Food –Fish –Water (SPMDs)

15. PCB and lipid analyses conducted by Battelle Laboratories, Duxbury, Mass. Aroclor 1254/1260 standard

16. Initial Trout Size 124 mm total length (SD = 5.9) 22.6 grams (SD = 3.8)

17. 6-Month Trial – Final Sizes DietMean Length (mm) Mean Weight (g) 1248197 2242183 3243185 4246194

20. Objectives 2. Of the PCBs consumed by trout, what proportion is assimilated?

21. Assimilation Study Add chromic oxide to feed – 1% by wt. Feed fish for 2 weeks Strip feces Analyze feces for PCBs and chromic oxide

22. Assimilation Experiment Diet% Assimilated 186.6 284.5 389.4 487.5 Mean = 87.0%

23. Objectives 3. If PCBs are present in hatchery supply water, what are the relative contributions of PCBs from the water and from the feed to the total found in trout?

24. SPMD Deployments 3 in source spring and 3 in tank with no fish Replace monthly

25. 12-Month Average Source Spring: 293 ng PCB/SPMD Inside Tank: 200 ng PCB/SPMD

26. Mass Balance Approach Initial Body Burden of PCBs + PCB uptake from feed = Expected Body Burden of PCBs

27. Actual body burden of PCBs minus Expected body burden of PCBs = Uptake of PCBs from water

28. Diet 2 – Month 1 Initial fillets370 ng of PCBs Initial carcasses2134 ng Absorbed from feed1557 ng Expected final total4061 ng Final fillets754 ng Final carcasses3726 ng Total final4480 ng Uptake from water423 ng

29. 24 Monthly Comparisons 8 comparisons: Actual > Expected –Uptake from water 16 comparisons: Expected > Actual –No evidence of uptake from water –Overall: Average difference –8.8%, meaning on average, no evidence of uptake from water

30. Summary PCB concentrations in fillets were positively related to PCB concentrations in feed With feed that had 126 ppb PCBs, concentrations in fillets after 6 months did not exceed advisory limit of 100 ppb

31. Summary PCBs were detected in the source water and there was no indication that the hatchery infrastructure contributed additional PCBs to the water Preliminary analyses suggest that uptake of PCBs from water was not important

32. Summary PCB uptake was primarily from the feed and trout assimilated a large a large proportion (87%) of PCBs in the feed