DOI: 10.6084/m9.figshare.7371017
title: Sediment Porosity, Density, %C, %N, and C:N ratios in Waquoit Bay, Massachusetts (USA)

description: On 7 occasions over the course of 3 years (2011-2013) we conducted hypoxic static core incubations on sediments and water collected in Waquoit Bay Massachusetts (USA) from four stations: Childs River Estuary, Metoxit Point, South Basin, & Sage Lot Pond. The goal of this study was quantify sediment metabolism under water column hypoxia in a shallow, temperate estuarine system. As part of that study we analyzed samples from incubated cores to determine sediment density, porosity, percent carbon (%C), percent nitrogen (%N), and molar carbon to nitrogen (C:N) ratios. These samples were collected using plastic (polycarbonate) syringe sub-cores (60 mL) that we sectioned up to 4 cm in 1 cm sub-samples. We stored the sediments in plastic centrifuge tubes (50 mL) in a freezer until they were analyzed. All sampling materials were acid washed and ethanol rinsed prior to sediment collection. We used standard processing and analysis protocols to determine sediment porosity, density (Nielsen et al. 2000) and %C %N (Zimmermann et al. 1997). Percent C and N samples were determined using an elemental analyzer at the Boston University Stable Isotopes Laboratory. For more information please see articles where these data are published (Foster & Fulweiler 2014, Foster & Fulweiler 2019). Email questions and comments to: sqfoster@bu.edu<br><b>Sampling Stations</b><br>CRE = Childs River Estuary (41° 34.805’ N 70°31.826’ W, 1.2 m deep, bottom water salinity 27.3-29.7 psu) MP = Metoxit Point (41° 34.134’ N 70° 31.272’ W, 2.2 m deep, bottom water salinity 29.6-31.3 psu) SB = South Basin (41° 33.404’ N 70° 31.442’ W, 1.8 m deep, bottom water salinity 30.6-31.3 psu)SLP = Sage Lot Pond (41° 33.270’ N 70° 30.584’ W, 1.2 m deep, bottom water salinity 28.9-30.4 psu)<br><b>Units</b>Depth Range = cmDensity = g/mLPorosity = sediment pore space to total volume ratioCarbon = percent carbon of total massNitrogen = percent nitrogen of total massC:N = carbon to nitrogen molar ratio<br><b>Abbreviations & Symbols</b>Date = dd (day) - month - yy (year)<br>Stn = Stationm.i. = measurement issuen.m. = not measured<br><b>Acknowledgments</b>There are numerous people who contributed to this project. We would like to thank the Waquoit Bay National Estuarine Research Reserve (WBNERR) for their continued multi-year support of our research. All sediment samples for this study were collected using WBNERR boats. We are particularly grateful to the following WBNERR employees who assisted with the fieldwork: MK Fox, A Lescher, J Mora, C Weidman. We would also like to thank several Fulweiler Lab members and Boston University Marine Program (BUMP) students for their assistance with fieldwork and sediment sub-coring in the lab: S Andrews, A Banks, S Buckley, K Czapla, S Donovan, D Forest, E Heiss, J Luthringer, M McCarthy, S Newell, MK Rogener, R Schweiker, K Yoshimura. In addition, S Donovan, S Duan, E Greenberg, R Lauto, and D Lewellyn, helped with sediment processing and density/porosity analysis. And R Michener in Boston University’s Stable Isotopes Laboratory analyzed sediment percent carbon and nitrogen. We also thank Boston University Earth and Environment Department for use of their facilities and their general academic and logistical research support.<br><b>References</b>Foster SQ, and RW Fulweiler. 2019. Estuarine sediments exhibit dynamic and variable biogeochemical responses to hypoxia. Journal of Geophysical Research: Biogeosciences, 124. https://doi.org/10.1029/2018JG004663<br>Foster SQ and RW Fulweiler. 2014. Spatial and historic variability of benthic nitrogen cycling in an anthropogenically impacted estuary. Frontiers in Marine Science 1. https://doi.org/10.3389/fmars.2014.00056.<br>Nielsen LP, V Brotas, P Viaroli, G Underwood, DB Nedwell, K Sundback, S Rysgaard, et al. 2000. Protocol handbook for NICE - Nitrogen Cycling in Estuaries: A Project under the EU reserach programme: Marine Science and Technology (MAST III). Edited by T Dalsgaard. National Environmental Research Institute, Silkborg, Denmark.<br>Zimmermann CF, CW Keefe, and J Bashe. 1997. Determination of carbon and nitrogen in sediments and particulates of estuarine/coastal waters using elemental analysis. US Environmental Protection Agency, Method 440: 9.<br>