00000nam##2200000za#4500 9.613661 CaOODSP 20241008111406 ta 150406|1997||||xxc||||| f|0| 0 eng|d 0-662-25529-1 CaOODSP eng n-cn--- En40-222/6-1997E Canadian Wildlife Service. Contaminants in herring gull eggs from the Great Lakes: 25 years of monitoring levels and effects / by D. P. Ryckman, D. V. Chip Weseloh and C. A. Bishop. Downsview - Ontario : Environment Canada. 1997. 12p. : coloured illus., graphs ; 28 cm. Great Lakes fact sheet Bibliography. Softcover 00-48 2000-12-01 Contamination gcpds Ecosystems gcpds Pesticides gcpds Birds gcpds Weseloh, D. V. Chip Ryckman, D. P. Bishop, C. A. Great Lakes fact sheet. (CaOODSP)9.514572