Proceedings - Teaching and Learning Centre - Simon Fraser ...

Fraser River Action Plan
3rd Research Workshop
Coplanar PCBs 77 and 126 were found in mink from below the Skookumchuk mill and in the lower
Fraser Valley (where they were slightly higher), but not in Slocan River mink.
Pesticides found in both the Kootenay system and the lower Fraser Valley were heptachlor epoxide,
hexachlorobenzene and oxychlordane. In addition, DDE, dieldrin and endosulfan II were found in the
lower Fraser Valley.
Quality Control and Variation
PESC analyses of heavy metals included two replicates and two standard reference samples. Most of the
two sets of replicates analyzed by ICP were acceptable (40% variation), but the graphite furnace gave a
couple of odd results. In a Kootenay mink kidney, the GF reported no detectable cadmium, but the ICP
result was 3.8 ug/g; likewise, one of the replicates reported no cadmium by GF, whereas its mate had 6.3
ug/g by GF, and 7.8 ug/g by ICP. These results were discussed with the analyst, and no reason for the
discrepancies were discovered. If the ICP result was the more accurate (if not as precise), then the
cadmium levels based on GF may be underestimated. All other samples were consistent between the GF
and ICP results, between the two pairs of replicates.
A whole liver sample split (not homogenized) during sample preparation and submitted to Zenon as a
separate sample was almost identical to its mate, although a number of individual PCB congeners varied
by up to about 50% at the ppb level. An internal laboratory duplicate analysis varied about the same. The
blanks were blank and the reference materials were within accepted limits of the certified values.
Biological
Few gross abnormalities were observed in the various otter examined, and most specimens were healthy
and fat, although some had no fat. Fish bones and scales were seen in several stomachs. A few parasites
(nematodes) were seen in one individual. One female had an enlarged spleen and no fat. A male had a
missing kidney and an undescended testis. Another had no testes. Total body length was weakly correlated
with weight, but baculum length in males was not correlated with total body length, as would have been
expected. Except as noted, bacula and testes were present in all males, except where the trapper was
incautious with the knife during skinning. No other obvious signs of reproductive impairment were
observed in males or females. One female had two fetuses. When chemical analytical results are received,
the organ measurements will be compared with contaminant levels.
Conclusions
These mustelids are relatively healthy and uncontaminated, but not free of environmental contaminants
that have become widely distributed. Mink from the Columbia River system had a greater variety of PCB
congeners, and those from the lower Fraser Valley had a greater variety of pesticide residues.
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