Amphibians were present in 118 potential breeding sites 9–66 km northeast and southwest of Sudbury, Ontario. Detailed chemical analyses were done for 38 ponds, and 23 variables were subjected to principal components analysis to summarize the main gradients in pond chemistry. Discriminant analysis using scores of the first three principal components showed that the presence of Rana pipiens, R. clamitans and Hyla crucifer was positively related to buffering status (alkalinity, pH, and other correlated variables); the presence of H. crucifer was also negatively related to atmospheric deposition status (cadmium, nickel, other correlated metals, and sulphate). Discriminant analysis using the original water chemistry variables confirms these general patterns. Two species show relationships with buffering status variables: Rana sylvatica with conductivity and R. clamitans with alkalinity. Three species also show negative correlation with metal levels in pond water: Bufo americanus with nickel, R. clamitans with aluminum, and R. pipiens with zinc. Although most of the species expected do occur in the Sudbury area, the distributions of several species appear related to buffering status and metals present in their immediate environemnt. There were only two observations of Ambystoma maculatum, and low numbers of egg masses were noted for R. sylvatica.

Abstract. During 1987-89, organochlorine contaminant levels were measured in American kestrel (Falco sparverius) eggs and in other components of the terrestrial ecosystem in Ontario, Canada. The extent to which these samples were contaminated with DDE varied geographically. Wet weight levels of DDE were greater in eggs from American kestrels (10.8 mg/kg), American robins (Turdus migratorius) (17.3 mg/kg), European starlings (Sturnus vulgaris) (8.8 mg/kg), and eastern bluebirds (Sailia sailis) (7.6 mg/kg) and in samples of earthworms (Lumbricus sp.) (0.6 mg/kg), soil (0.3 mg/kg) and vegetation (8

No abstract

The decline of wetlands, including those in the Great Lakes coastal zone, prompted the Government of Ontario to initiate steps towards a wetland management policy in 1981. Wetland inventory and evaluation in southern Ontario began in 1983. To date, 1982 wetlands have been evaluated totalling 390 000 ha. These include 160 coastal wetlands, 64 of these on Lake Ontario and the remainder on the other Great Lakes and connecting channels. Current wetland conservation initiatives are outlined including the Wetlands Planning Policy Statement and Conservation Lands Act. Although the values of Ontario's coastal wetland areas are increasingly being recognized, there has been no comprehensive study to show patterns in coastal wetland ecology. Aided by analysis of variance, ordination, and cluster analysis, we show patterns of variation in wetland and site types, soils, dissolved solids, vegetation complexity, and rare flora and fauna which differ between wetlands along Lakes Ontario, Huron, Erie, St. Clair, and connecting channels. Wetlands of Lake Huron reflect a more northern species composition, less organic soil, and more swamp and fen habitat. Along Lakes Erie, Ontario, and St. Clair the predominant marshes have smaller swamp components, organic soils, and considerable dissolved solids.