Sediment particles can strongly bind metals, effectively repartitioning them from solution to a solid phase. As a result, sediments may accumulate and retain metals released to an aquatic environment. Sediment cores provide a historical record of metal inputs that can reveal anthropogenic influences (Förstner and Wittmann, 1979). Specifically, studies of sediment cores in San Francisco Bay chronicled metal inputs and suggested that legacy contamination can remain a chronic source of metals to the system owing to sediment mixing and redistribution (Hornberger and others, 1999; Van Geen and Luoma, 1999). Metals in sediments also indicate exposure levels to benthic animals through contact with, and ingestion of, bottom sediments and suspended particulate materials. However, physical and geochemical conditions of the sediment affect the biological availability of the bound metals. Assimilation of bioavailable sediment-bound metal by digestive processes and the contribution of this source of metals relative to metals in the aqueous phase are difficult to predict from sediment concentrations alone. Thus, in order to better estimate bioavailable metal exposures, the tissues of organisms may be analyzed for trace metals (Phillips and Rainbow, 1993). Different species concentrate metals to different degrees. However, if one species is analyzed consistently, the results can be used to track temporal changes in trace-element exposures at a specified location. This data release includes the sediment and tissue metal data starting in January 2019 and is presented in 13 tables as comma-separated values (.CSV) files as follows: T1_Sediment_Summary as a summary of the fine sediment, silver, aluminum, chromium, copper, iron, mercury, nickel, selenium, zinc and total organic carbon in the sediment. T2_Sediment_Metals_ICPOES provides detailed silver, aluminum, chromium, copper, iron, mercury, nickel, selenium and zinc data collected by inductively coupled plasma-optical emission spectrophotometry (ICP-OES) T3_Sediment_Hg_Se reports detailed mercury and selenium data T4_TOC reports detailed total organic carbon data from the sediment T5_Tissue_Metals reports the silver, chromium, copper, nickel, and zinc data collected from clams with the size and mass of the collected clam tissue for each sample date. T6_Tissue_Hg_Se reports the mercury and selenium data collected from clam tissue collected by size fraction and collection date. T7_QA_ICPOES_Sediment_SRM reports the standard reference material run data for certified reference standards for sediment analyzed on the ICP-OES. T8_QA_ICPOES_Tissue_SRM reports the standard reference material run data collected for certified standards for biological tissues analyzed on the ICP-OES. T9_QA_Hg_ Se reports the standard reference materials run for mercury and selenium data T10_QA_Spike_Recovery reports the spike recovery runs for the ICP-OES T11_QA_ICPOES_Blanks reports the procedural blanks run on the ICP-OES T12_QA_MDL_MRL reports the annual method detection limits and method reporting limits for the listed analyte T13_QA_SRM_reference_values reports the reference values for each of the reported standard reference material included in this data release

Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat located 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, California. This report includes data collected by the U.S. Geological Survey (USGS) starting in January 2019. These data append to long-term datasets extending back to 1974. This dataset supports the City of Palo Alto’s Near-Field Receiving-Water Monitoring Program, initiated in 1994. This data release is presented as two datasets each on its own child page. The first child page contains clam tissue metals data, sediment metals data, percentage fine sediment, total organic carbon, and the salinity of the overlying water. The second child page contains clam reproduction and benthic community data. Please read the metadata file corresponding to each dataset for complete details.

The three files contain trace metal data from North, Central and South Atlantic observed in bottom sediment samples along the East Coast Continental Slope and Rise region. Samples were collected from a large number of surveys from May 1983 to July 1986. These data were collected by National Marine Fisheries Service, Woods Hole for the US East Coast Continental Rise/Slope region. The documentation includes the field variables (including region, box core number, location, and type of metal recorded) and a listing of cruises.

Benthic organisms and marine toxic substances and pollutants were collected using net casts, sediment sampler, and other instruments from the GYRE and other platforms in NW Atlantic Ocean. Data were collected from 11 November 1983 to 30 July 1986. Data were submitted by Battelle Marine Research Laboratory in New England with support from the New England Shelf and Slope Program. Data has been processed by NODC to the NODC standard F132- Benthic Organisms and F144- Marine Toxic Substances and Pollutants formats. The F132 format contains data from field sampling or surveys of bottom dwelling marine organisms. The data provide information on species abundance, distribution, and biomass; they may have been collected by point sampling (grab or core), by tow (dredge, trawl or net), by photographic surveys, or by other methods. Cruise information such as vessel, start and end dates, investigator, and institution/agency; station numbers, positions and times; and equipment and methods are reported for each survey. Environmental data reported at each sampling site may include meteorological and sea surface conditions; surface and bottom temperature, salinity and dissolved oxygen; and sediment characteristics. Number of individual organisms and total weight of organisms is reported for each species. A text record is available for comments. The F144 format contains data on ambient concentrations of toxic substances and other pollutants in the marine environment. The data derive from laboratory analyses of samples of water, sediment, or marine organisms. Samples may have been collected near marine discharge sites or during ocean monitoring surveys of large areas. Field observations of tar deposits on beaches may also be reported. Survey information includes platform type, start and end dates, and investigator and institution. If data are collected near a discharge site, discharge location, depth, distance to shore, average volume, and other characteristics are reported. Position, date, time and environmental conditions are reported for each sample station. Environmental data may include meteorological and sea surface conditions, tide stage and height, depth of the thermocline or mixed layer surface temperature and salinity, and wave height and periods. Sample characteristics, collection methods, and laboratory techniques are reported for each sample collected and analyzed. The data record comprises concentration values (or a code to indicate trace amounts) for each chemical substance analyzed. Chemical substances are identified by codes based on the registry numbers assigned by the Chemical Abstracts Service (CAS) of the American Chemical Society. Marine organisms from which samples have been taken are identified using the 12-digit NODC Taxonomic Code. A text record is available for optional comments.

The accession contains Benthic and Tissue toxin data from stations in U.S. coastal waters (Coastal Waters of Western U.S. and North American Coastline-North) collected under the National Status and Trends (NS&T) program from 1984-1989. NS&T program for marine environmental quality was designed to define the geographic distribution of contaminant concentrations in tissues of marine organisms and sediments, and documenting biological responses to contamination. Samples have been collected under the original Benthic Surveillance Project (sediment and tissue samples from benthic fish) since 1984. Samples have been collected under the Mussel Watch Project (sediment and bivalves) since 1986. Both programs involved collecting samples from fixed sites on both Atlantic and Pacific coasts. Sites were selected so as not to be in close proximity to a major contamination source, as the programs objective was to quantify contamination over general areas. Chemical data from sediments collected during the benthic surveillance project, 1984-1986, is contained in a single delimited ASCII file (bssed.txt). Additional contaminated sediment data from the mussel watch program, 1986-1989, is contained in a single delimited ASCII file (mwsed.txt). These data do not include tissue analysis for contaminants. Chemicals and related parameters measured in sediments include: DDT. Since 1986, NOAA'S NS&T Program has included a component called the mussel watch project that has annually collected and chemically analyzed mussels and oysters from 177 sites at coastal and estuarine sites. Tissue samples from these mollusks have been analyzed to establish temporal trends of contaminant accumulation. Contaminants analyzed during this project include: polyaromatic hydrocarbons, polychlorinated biphenyls, chlorinated pesticides (such as DDT and its metabolites), aluminum, iron, manganese, silicon, other trace elements, and lipids. Tissue contaminant data from the mussel watch project, years 1986-1989, is contained in a single wordperfect 4.2 file, mollto90.txt. A second file, tbt_90.txt, lists the sum of concentrations of tributyltin and its breakdown products (dibutyltin and monobutyltin) found in bivalve tissue samples. Tributyltin (TBT) was previously used as an antifouling agent in paints, but its use on vessels under 75 feet was banned in 1988. A third file, mwsiteyr.txt, lists collection sites.

Data has been processed by NODC to the NODC standard Marine Toxic Substances and Pollutants (F144) format. The F144 format contains data on ambient concentrations of toxic substances and other pollutants in the marine environment. The data derive from laboratory analyses of samples of water, sediment, or marine organisms. Samples may have been collected near marine discharge sites or during ocean monitoring surveys of large areas. Field observations of tar deposits on beaches may also be reported. Survey information includes platform type, start and end dates, and investigator and institution. If data are collected near a discharge site, discharge location, depth, distance to shore, average volume, and other characteristics are reported. Position, date, time and environmental conditions are reported for each sample station. Environmental data may include meteorological and sea surface conditions, tide stage and height, depth of the thermocline or mixed layer surface temperature and salinity, and wave height and periods. Sample characteristics, collection methods, and laboratory techniques are reported for each sample collected and analyzed. The data record comprises concentration values (or a code to indicate trace amounts) for each chemical substance analyzed. Chemical substances are identified by codes based on the registry numbers assigned by the Chemical Abstracts Service (CAS) of the American Chemical Society. Marine organisms from which samples have been taken are identified using the 12-digit NODC Taxonomic Code. A text record is available for optional comments.

These data are part of the Southern California OCS Baseline Study funded by BLM and submitted by Science Applications, Inc. Coastal areas along southern California were sampled. Following is a list of purpose for which the study was conducted, the period when the data was collected and the type of data collected. Sampling was done from July 1, 1975 to November 6, 1977 to obtain depth, temperature and salinity profiles. During the same time period data was collected to measure the amounts of particulate organic carbon (POC), dissolved organic carbon (DOC), and ATP. Analysis was done for intertidal hydrocarbon (HC) concentrations from July 1, 1975 to June 30, 1978. Fractions analyzed include aliphatic and aromatics, pristane and phytane, iso-n and branched hydrocarbons, odd/even preference, and the hexane, benzene and methane fractions. Analysis was done for benthic hydrocarbon (HC) concentrations from July 1, 1975 to November 6, 1977. Fractions analyzed include aliphatic and aromatics, pristane and phytane, iso-n and branched hydrocarbons, odd/even preference, and the hexane, benzene and methane fractions. Sampling was done to assess the trace metal concentrations from July 1, 1975 to November 6, 1978. Benthic fauna, sediments and the water column were analyzed for Ba, Cd, Cr, Cu, Fe, Ni, Pb, V, Zn and Al concentrations. Sampling was done to assess the trace metal concentrations from July 1, 1975 to November 6, 1978. Intertidal rocky and sandy fauna, and sediments were analyzed for Ba, Cd, Cr, Cu, Fe, Ni, Pb, V, Zn and Al concentrations. Benthic coastal sediments along southern California were sampled from July 1, 1975 to November 6, 1977. The analysis includes sediment age, grain size, total organic carbon (TOC), total inorganic carbon (TIC), total carbon (TC), calcium carbonate content and mineral composition, as well as a description of the field conditions during sampling. Identical analysis was conducted on samples collected during July 1, 1975 to June 30, 1978. Intertidal coastal sediments along southern California were sampled from July 1, 1975 to June 30, 1978. The analysis includes sediment age, grain size, total organic carbon (TOC), total inorganic carbon (TIC), total carbon (TC), calcium carbonate content and mineral composition, as well as a description of the field conditions during sampling. Coastal areas along southern California were sampled from July 1, 1976 to June 30, 1978 and the composition of the benthic microfauna and benthic macrofauna was analyzed. Coastal areas along southern California were sampled from July 1, 1975 to June 30, 1978. Data includes files describing the biotic/abiotic mussel community and a species dictionary as well as a description of the field conditions. Rocky coastal beaches along southern California were sampled from July 1, 1975 to June 30, 1978 and the composition of the intertidal rocky fauna was analyzed. Included in these data is a file on rocky intertidal fauna succession and a description of the field conditions. Sandy coastal beaches along southern California were sampled from July 1, 1975 to June 30, 1978 and the composition of the sandy intertidal fauna was analyzed.

Benthic organism and marine toxic substances and pollutants were collected using net, sediment sampler, and other instruments from NOAA Ship RESEARCHER and other platforms in the Gulf of Mexico. Data were submitted by the Energy Resources Co., INC. with support from IXTOC project. Data were collected from 23 July 1979 to 13 December 1980. Data has been processed by NODC to the NODC standard F132- Benthic Organisms and F144- Marine Toxic Substances and Pollutants formats. The F132 format contains data from field sampling or surveys of bottom dwelling marine organisms. The data provide information on species abundance, distribution, and biomass; they may have been collected by point sampling (grab or core), by tow (dredge, trawl or net), by photographic surveys, or by other methods. Cruise information such as vessel, start and end dates, investigator, and institution/agency; station numbers, positions and times; and equipment and methods are reported for each survey. Environmental data reported at each sampling site may include meteorological and sea surface conditions; surface and bottom temperature, salinity and dissolved oxygen; and sediment characteristics. Number of individual organisms and total weight of organisms is reported for each species. A text record is available for comments. The F144 contains data on ambient concentrations of toxic substances and other pollutants in the marine environment. The data derive from laboratory analyses of samples of water, sediment, or marine organisms. Samples may have been collected near marine discharge sites or during ocean monitoring surveys of large areas. Field observations of tar deposits on beaches may also be reported. Survey information includes platform type, start and end dates, and investigator and institution. If data are collected near a discharge site, discharge location, depth, distance to shore, average volume, and other characteristics are reported. Position, date, time and environmental conditions are reported for each sample station. Environmental data may include meteorological and sea surface conditions, tide stage and height, depth of the thermocline or mixed layer surface temperature and salinity, and wave height and periods. Sample characteristics, collection methods, and laboratory techniques are reported for each sample collected and analyzed. The data record comprises concentration values (or a code to indicate trace amounts) for each chemical substance analyzed. Chemical substances are identified by codes based on the registry numbers assigned by the Chemical Abstracts Service (CAS) of the American Chemical Society. Marine organisms from which samples have been taken are identified using the 12-digit NODC Taxonomic Code. A text record is available for optional comments.

Determining spatial distributions and temporal trends in trace metals in sediments and benthic organisms is common practice for monitoring environmental contamination. These data can be the basis for assessing metal exposure, the potential for adverse biological effects, and the response to regulatory or management actions (Suter, 2001). Another common method of environmental monitoring is to examine the community structure of sediment-dwelling benthic organisms (Simon, 2002). Spatial and temporal changes in community structure reflect the integrated response of resident species to environmental conditions, although the underlying cause(s) for the response may be difficult to identify and quantify. Together, measurements of metal exposure and biological response can provide a more complete view of anthropogenic disturbances and the associated effects on ecosystem health. Despite the complexities inherent in monitoring natural systems, the adopted approach has been effective in relating changes in near-field contamination to changes in reproductive activity of a clam (Hornberger and others, 2000) and in benthic community structure (Kennish, 1998). This study, with its basis in historical data, provides a rare multi-decadal context within which future environmental changes can be assessed.

Chemical, benthic organisms, and other data were collected using moored current meter casts and other instruments in the Gulf of Mexico from November 11, 1983 to November 13, 1984. Data were submitted by Alaska Research Associates, Inc., as part of the Gulf of Mexico North Continental Slope Study (MNCSS) project. Data has been processed by NODC to the NODC standard F004 Water Physics and Chemistry, F123 Fish Shellfish Resource, and F132 Benthic Organisms formats. The F004 format is used for data from measurements and analyses of physical and chemical characteristics of the water column. Among chemical parameters that may be recorded are salinity, pH, and concentration of oxygen, ammonia, nitrate, phosphate, chlorophyll, and suspended solids. Physical parameters that may be recorded include temperature, density (sigma-t), transmissivity, and current velocity (east-west and north-south components). Cruise and station information, including environmental conditions of the study site at the time of observations, is also included. The F123 format is used for data from field sampling of marine fish and shellfish. The data derive from analysis of midwater or bottom tow catches and provide information on population density and distribution. Cruise information, position, date, time, gear type, fishing distance and duration, and number of hauls are reported for each survey. Environmental data may include meteorological conditions, surface and bottom temperature and salinity, and current direction and speed. Bottom trawl or other gear dimensions and characteristics are also reported. Catch statistics (e.g., weight, volume, number of fish per unit volume) may be reported for both total haul and for individual species. Biological characteristics of selected specimens, predator/ prey information (from stomach contents analysis), and growth data may also be included. A text record is available for comments. The F132 format contains data from field sampling or surveys of bottom dwelling marine organisms. The data provide information on species abundance, distribution, and biomass; they may have been collected by point sampling (grab or core), by tow (dredge, trawl or net), by photographic surveys, or by other methods. Cruise information such as vessel, start and end dates, investigator, and institution/agency; station numbers, positions and times; and equipment and methods are reported for each survey. Environmental data reported at each sampling site may include meteorological and sea surface conditions; surface and bottom temperature, salinity and dissolved oxygen; and sediment characteristics. Number of individual organisms and total weight of organisms is reported for each species. A text record is available for comments.