PARENT SESSION

IP11 Investigations of the Columbia River and Estuary (USA)
B113 & B114
8:00 AM - 12:00 PM, Thursday

(IP096) Osprey Eggs Used to Determine Spatial Residue Patterns and Effects of Contaminants Along Columbia River.

Henny, C¹, Grove, R¹, Kaiser, J¹, Bentley, V¹, ¹ U.S. Geological Survey, Corvallis, OR, USA

ABSTRACT- An Osprey (Pandion haliaetus) population nesting along the lower 410 km of the Columbia River (94 occupied nests in 1997; increased to 103 in 1998) was studied to evaluate the merit in using the species for monitoring selected contaminants that biomagnify in food chains. We collected a sample egg from 29 Osprey nests and analyzed egg contents for residue concentrations of OC pesticides, PCBs, PCDDs, PCDFs and total mercury. Reproductive success was monitored at all nests, including those with an egg collected, to evaluate possible contaminant effects on reproductive success. The lower Columbia River study area was subdivided into four distinct reaches primarily based on locations of major industrial areas, urban boundaries, and other known point sources of pollution. Residue concentrations in Osprey eggs for most contaminants did not vary significantly among reaches. However, eggs collected from Reach II (immediately below the Bonneville Dam hydroelectric facility) contained significantly higher concentrations of PCB 105 (nearly all PCB congeners were higher) compared to eggs collected in Reach I (upstream) or Reach III (downstream). An historic landfill of electrical equipment containing PCBs was reported at Bonneville Dam in 2000, 2 years after completion of this field study. Osprey eggs contained the highest concentrations of p, p'-DDE (DDE) (geometric mean 4872 g kg-1 wet weight, with 24% of eggs > 8000 g kg-1) reported for the species in North America during the late 1980s and 1990s. Furthermore, DDE adversely influenced eggshell thickness and success at some nests. As expected, elevated DDE concentrations were found in fish from the Columbia River. Other contaminants appeared to have limited, if any, adverse effects on Osprey reproduction. With most Osprey populations now increasing and pairs pioneering into more contaminated areas, we believe the Osprey may be a useful indicator for the biomonitoring of selected contaminants.

Key words: Columbia River, Monitoring, Osprey, DDE