This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the Delaware Bay system in terms of chemical contamination, sediment toxicity (Microtox, amphipod bioassay; sea urchin gamete bioassay; and P450 biomarker) and benthic infaunal community structure. The purpose was to define the extent and magnitude of toxicity and other biological effects associated with contaminants in the Delaware estuary system from the fall line to the mouth of the Bay. This file contains data measured in the Delaware Bay Estuary and adjacent waters during 1997. Samples were collected for water and sediment analyses.