R5 PM Avian Sentinels of Environmental Contamination
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in 321-323

(ELL-1117-658852) Use of satellite telemetry to track southward migration of Pacific Northwest ospreys and contaminant exposure on wintering grounds.

Elliott, J¹, Morrissey, C¹, Shaw, P², Ruelas, E³, Henny, C⁴, ¹ Canadian Wildlife Service, Delta, BC, Canada² Environment Canada, Vancouver, BC, Canada³ Pronatura Veracruz, Xalapa, VZ, Mexico⁴ USGS, Corvallis, OR, USA

ABSTRACT- During 1996-2002, 18 satellite transmitters were mounted on Ospreys breeding in British Columbia, Canada, to follow the southward migration and to locate major wintering areas in Latin America. Sixteen Ospreys were successfully tracked through their fall migration and found wintering primarily in Mexico (56 %) but also in Texas, USA (19 %), Central America (Panama, Nicaragua and Costa Rica) (19 %) and South America (Venezuela) (6 %). In order to assess the origin of dichloro-diphenyl-dichloroethylene (DDE) and other chlorinated hydrocarbons found in eggs of breeding Osprey from the Pacific Northwest, we designed the study to examine prey contaminant residues in several common fish species (n = 8 families) from major Osprey wintering areas in Mexico (n = 5 states). Concentrations of the main organochlorine contaminant, p,p'-DDE, in fish composites ranged from 4.8 - 115.2 ng/g ww. Significant differences existed among fish families in p,p'- DDE (p = 0.001), total dichloro-diphenyl-trichloroethylene (p,p'-DDT) (p = 0.003), total chlordanes (p = 0.002) and sum PCBs (p = 0.02). Catfish (Family Ariidae) generally had significantly higher levels of DDT metabolites and other organochlorine contaminants compared to other fish families collected. Differences in prey contaminant levels were detected among the collection sites around coastal Mexico, with fish from Veracruz State generally having higher levels of DDT metabolites, total chlordanes, sum PCBs and hexachlorobenzene. Eggs collected from satellite-tagged Ospreys breeding throughout the Pacific Northwest (British Columbia, Oregon and Washington) showed marked variation in levels of DDT metabolites (p,p'-DDE: range 0.02 -10.1 mg/kg ww) that were related to local breeding sites but did not appear to be influenced by specific wintering ground exposure. Ospreys breeding in the Williamette basin, Oregon and Ospreys that migrated to Central or South America had lower p,p'-DDE levels in eggs and also had higher ratios of DDE:DDT, suggesting historic low level exposure rather than recent exposure to DDT compounds.

Key words: Osprey, Organochlorines, Migration, Telemetry