Assessment of Potential Indicator Species for Monitoring ...

higher in those from the northern Bay region. Mean concentrations of
arsenic, copper, lead, zinc, aluminum (January only) and iron (January) also
differed among individual locations. Mean concentrations of copper and zinc
increased, arsenic decreased, and cadmium remained the same between
January and March. Selenium and mercury concentrations in scoter livers
were not significantly correlated (P > 0.05), but cadmium concentrations in
livers and kidneys were positively correlated (P < 0.0001), and body weight
was negatively related to mercury concentration in the liver (P < 0.05). Body
weight differed among locations but not between January and March. Body
weight was correlated with lipid content (P < 0.0001). DDE PCBs were each
detected in 34 of 36 scoter carcasses. DDE increased significantly between
January and March at Richmond Harbor, but PCBs did not differ between
January and March at the three locations that could be tested.
O7) Olson, M.M. and D. Welsh. 1993. Selenium in Eared Grebe embryos from
Stewart Lake National Wildlife Refuge, North Dakota. Prairie Nat. 25:
119-126.
Abstract: Selenium in 41 Eared Grebe (Podiceps nigricollis) eggs, from
Stewart Lake National Wildlife Refuge (Stewart Lake), North Dakota,
averaged 4.5 mug/g dry weight (range 2.9-6.5 mug/g), and is above the 85 th
percentile (3.2 mug/g dry weight) of mean concentrations in background
investigations of selenium in eggs from the western United States. The best
available estimate of hatchability indicated that 16.0% of all grebe eggs
examined would not have hatched. No deformities were noted in the
examined embryos. Dates of nest initiation spanned 24 days (17 June to 12
July 1991), with peak nest initiation occurring on 3 July. There was no
correlation between selenium concentration in eggs and date of nest
initiation, suggesting that selenium accumulation in grebes at Stewart Lake
reaches equilibrium before egg laying occurs.
O8) Orchard, S.A. 1984. Amphibians and Reptiles in British Columbia: An Ecological
Review. Report to Ministry of Forests, Victoria. 268 pp.
Summary: The report presents a introduction to amphibians and reptiles in British
Columbia and detailed species accounts. Where information is lacking or scant this
is stated clearly. The status of each species is also given.
O9) Orchard, S.A. 1988. Wildlife Habitat Handbooks for the Southern Interior
Ecoprovince. Volume 4: Species Notes for Amphibians. Wildlife Habitat Research
WHR-31. Wildlife Report No. R-18.
O10) Orchard, S.A. 1992. Amphibian population declines in British Columbia. In: Bishop
C.A. and K.E. Pettit (eds.). Declines in Canadian amphibian populations: designing
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