Concentrations of Metals in Blood and Feathers of Nestling Ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays

Abstract

In 2000, 2001, and 2002, blood and feather samples were collected from 40-45-day-old nestling ospreys (Pandion haliaetus) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater (p < 0.05) in two of three Chesapeake Bay regions of concern (Baltimore Harbor [As: 1.18 vs. 0.548 microg/g dw], Anacostia River [Hg: 0.305 vs. 0.178 microg/g dw], and Elizabeth River [As: 0.876 vs. 0.663 microg/g dw; Hg: 0.260 vs. 0.180 microg/g dw]). Lead was detected more frequently in blood of nestlings from the highly industrialized Elizabeth River compared to the rural reference area. When compared to the concurrent reference area, mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater (p < 0.05) in one or more Chesapeake regions of concern (Anacostia River [Al: 206 vs. 62.1 microg/g dw; Ba: 3.31 vs. 0.823 microg/g dw; Mn: 65.4 vs. 22.9 microg/g dw] and Elizabeth River [Al: 165 vs. 63.5 microg/g dw; Hg: 1.24 vs. 0.599 microg/g dw; Pb 1.47 vs. 0.543 microg/g dw]). When compared to the coastal Inland Bays reference area, feathers of nestlings from northern Delaware Bay and River had greater concentrations (p < 0.05) of Ba (1.90 vs. 0.660 microg/g dw), Fe (258 vs. 109 microg/g dw), Mn (18.5 vs. 4.66 microg/g dw), Mo (0.130 vs. 0.040 microg/g dw), Pb (1.96 vs. 0.624 microg/g dw), and V (0.671 vs. 0.325 microg/g dw), presumably due to extensive metal-working and petroleum refinery activities. Concentrations of Hg in nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.