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The article presents a study of environmental radioactivity of the Elliot lake region, Canada and assay of radium levels (Ra-226) in local mink and otter bones. Uranium mines and mills were located in the upper and middle sections of the Serpent River watershed that drains to the North Channel of Lake Huron at Serpent Harbour. Changes in water quality (principally pH and dissolved Ra-226 levels) reflect changes in mining practices, levels of mining activity, and in the treatment of effluents during this period. Two 250 mL aliquots of the stored liquid were analyzed for Ra-226 by the modified cz-spectroscopic technique. Result showed that mean Ra-226 levels in bone of Elliot Lake mink did not differ significantly between years but were significantly higher than that of the reference group.

Understanding the factors which influence the survival of juvenile American Black Ducks is critical to maintaining or enhancing rates of recruitment, a factor important in meeting the stated population goals of the North American Waterfowl Management Plan. To contribute to that knowledge base, and to compare survival on wetlands under different management strategies, this five-year study of radio-marked HY juvenile Black Ducks was initiated in the Maritime Provinces of AtlanticCanada. Two hundred and forty-six radio-marked juvenile American Black Ducks (Anas rubripes) were monitored on three study sites in New Brunswick and Nova Scotia during the summer/fall periods from 1987 through 1991. The three sites represented wetlands under the following management strategies: unmanaged forested (UF); managed-hunted (MH); and managed-sanctuary (MS). Post-fledging dispersal (>/= 10 km from natal marsh) was greatest (26%) on UF and least (1%) on MS. Mortality from hunting on or near natal wetlands was only slightly greater on MH(56%) than on MS (48%). Ore-half of the mortality from hunting on juveniles produced on UF occurred on nearby (10-25 km) managed wetlandsused for fall staging. Most radio-marked Black Ducks migrated south by early December, and mortality from hunting continued through December on wintering areas in southern Nova Scotia and northeastern United States. Total documented mortality on juveniles from hunting for MH, MS and UF was 60%, 57% and 22%, respectively. Managed wetlands on northern Black-Duck breeding habitat may discourage post-fledging dispersal and contribute to high losses of HY juveniles to hunting early in the season. Size of protected wetlands and juxtaposition with other non-protected wetlands should be considered when developing sanctuaries or managed reserves to enhance Black Duck production and subsequent juvenile survival through the fall hunting season. [ABSTRACT FROM AUTHOR]