THE ROLE OF CONTAMINANT EXPOSURE AND HABITAT SUITABILITY IN NEST SITE USE AND PRODUCTIVITY OF OSPREYS (PANDION HALIAETUS) BREEDING ON THE DELAWARE RIVER AND BAY

Abstract

In 2002, contaminant exposure, reproduction, and habitat use of ospreys along 3 segments of a 300-km stretch of the Delaware Bay area, and a reference area were evaluated. Fresh eggs were collected and analyzed for contaminants; fate of nests was monitored through fledging. Concentrations of p,p?-DDE and PCBs in eggs collected between the C&D Canal and Trenton resembled elevated levels found in the Chesapeake Bay. Productivity for Inland Bays and southern Delaware Bay was 1.17 and 1.42 young fledged/active nest; north of the C&D Canal productivity averaged 1 fledgling/active nest. An examination of osprey habitat use showed that presence of active nests was associated with water depth and clarity, distance to active osprey nests, and presence of urban land, while hatching success was associated with organic contaminants in eggs. Contaminants continue to be a significant stressor on osprey productivity, particularly in the northern Delaware Bay area.