This data set presents pore water nutrient concentrations and sediment oxygen demand (SOD) measurements made at 12 locations around the margin of Barnegat Bay and at 3 locations in central Barnegat Bay. The data were collected during 2012-2013 for the Barnegat Bay Nutrient Study in cooperation with the New Jersey Department of Environmental Protection. Table 1 presents the site data including site name, geographical location, site ID, and latitude and longitude. Table 2 presents concentrations of water quality constituents measured in water at the sediment interface and in pore water. Pore water was measured using in-situ equilibrium dialysis samplers (peepers) deployed at the stations. Measured concentrations in pore water were used to calculate nutrient flux rates between sediment pore water and overlying Bay water. Tables 3 and 4 present the composition and grain-size distribution of sediment from the benthic surface at the test sites. Table 5 presents SOD test results including date, water parameters, test duration, and the parameters used to develop best-fit least-square lines to the oxygen consumption data; these include slope (the SOD rate), intercept, correlation coefficient, and calculated SOD. These data support the following publication: Wilson, T. and DePaul, V., 2017, In situ benthic nutrient flux and sediment oxygen demand in Barnegat Bay, New Jersey, in Buchanan, G.A., Belton, T.J., and Paudel, B., eds., A Comprehensive Assessment of Barnegat Bay-Little Egg Harbor, New Jersey: Journal of Coastal Research, Special Issue 78, p. 46-59, https://doi.org/10.2112/SI78-005.1.