Chemistry data associated with tissue and samples of various media collected in the Gulf of Mexico from April 2010 through March 2012

The focus of this data posting is chemistry data associated with tissue and samples of various media collected during studies focused primarily on the sampling of tissue, and provides additional context for the posted dataset, including information about the collection, analysis, and organization of the data. This data posting differs from other recently published datasets relating to the Gulf of Mexico in several respects: This tissue chemistry dataset focuses only on information related to petroleum-related chemical constituents in tissue and related samples. This dataset combines results from 32 NRDA studies to create a unified data file. Tissue samples were not analyzed as part of the Response actions. Before posting, extensive work was done independently by BP contractors to verify some aspects of the posted data (e.g., positional coordinates and field data). Samples were collected from locations both onshore and in federal and state jurisdictional waters in the Gulf of Mexico from April 2010 through March 2012. More than 5,200 samples with associated chemistry analyses collected at over 2,500 sampling stations are included in this posting. These samples were collected during 32 studies, using 40 sampling cruises and surveys. These studies can be classified into three general categories: NRDA Cooperative—Studies conducted as part of the NRDA which were agreed to and executed cooperatively by the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Interior (DOI), and/or other Trustees, and BP. Trustee Independent—Studies conducted by NOAA, DOI, and/or other Trustees independently to develop data to support and inform the NRDA. Independent (Mussel Watch)—Long-running NOAA program for contaminant monitoring. Data for May and November 2010 are included. The chemical parameters provided in this data posting include: Parent and alkylated polycyclic aromatic hydrocarbons (PAHs), including some non-PAH compounds Saturated hydrocarbons (SHC) Total petroleum hydrocarbons (TPH), including parameters reported as total extractable material (TEM) Geochemical biomarkers (sterane and triterpane), where available Dispersant markers, Metals, Total organic carbon, Lipids. This dataset includes data associated with natural field samples for tissue and other sample matrices, along with the associated field-collected quality control samples, such as field replicates, equipment blanks, field blanks, and trip blanks. Laboratory duplicate sample data are provided, where available. Mississippi Canyon lease block 252 (MC252) control oils associated with chemistry analyses are part of a separate data posting (see Version History). No other laboratory quality control samples (e.g., laboratory blanks or spike samples) are included in this data posting.