The Ocean Archive System searches our original datasets as they were submitted to us, not individual points or profiles. If you want to search and retrieve ocean profiles in a common format, or objectively analyzed fields, your better option may be to use one of our project applications. See: Access Data
OAS accession Detail for 0291316
| << previous | |revision: 1 |
| accessions_id: | 0291316 | archive |
|---|---|
| Title: | Coastal phytoplankton and mercury dynamics in watersheds along the U.S. East Coast from New Jersey to Maine assessed using particulate and dissolved samples collected in 2015 and 2016 (NCEI Accession 0291316) |
| Abstract: | This dataset contains biological, chemical, and physical data collected in the North Atlantic Ocean from 2015-08-01 to 2016-07-01. These data include bottle salinity, chlorophyll a, dissolved organic Carbon, and total phaeopigment. The instruments used to collect these data include Automated Mercury Analysis System, Cold Vapor Atomic Fluorescence Spectrophotometer, Salinity Sensor, and Total Organic Carbon Analyzer. These data were collected by Robert Mason of University of Connecticut as part of the "Collaborative Research: Transformations and mercury isotopic fractionation of methylmercury by marine phytoplankton (Phytoplankton MeHg)" project. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2021-02-22. The following is the text of the dataset description provided by BCO-DMO: Dataset Description: The data in each year are grouped by Location, Filter size, and measured parameters for each size fraction, as well as the measured dissolved parameters: Location : state, site name and sub-location (in many instances these are sites with high (HOC) and low (LOC) organic carbon sediments), sampling month and sampling time in terms of tide (HT = high tide, LT = low tide, FL = falling and RS = rising tide; if more than one sample at a tide was collected, this is indicated, e.g. HT1, HT2), latitude and longitude Filter size : Filtering protocols were not exactly identical between years. In 2015, samples were sequentially filtered so particulate samples are >20 µm (large fraction) and 0.2-20 µm (small fraction). In 2016, water was sampled through filters independently so samples are >2 µm (bulk) and Dissolved parameters : For each location, a filtered sample was analyzed for: dissolved total mercury (diss. HgT, pM), dissolved methylmercury (diss. MeHg, pM), and dissolved organic carbon (DOC, µM). Salinity and temperature (degrees C) were also recorded for each sample. |
| Date received: | 20210222 |
| Start date: | 20150801 |
| End date: | 20160701 |
| Seanames: | |
| West boundary: | -75.475 |
| East boundary: | -68.791 |
| North boundary: | 44.763 |
| South boundary: | 38.928 |
| Observation types: | |
| Instrument types: | |
| Datatypes: | |
| Submitter: | |
| Submitting institution: | Biological and Chemical Oceanography Data Management Office |
| Collecting institutions: | |
| Contributing projects: | |
| Platforms: | |
| Number of observations: | |
| Supplementary information: | Acquisition Description: Coastal phytoplankton measurements were taken from 22 sites wtihin watersheds along the U.S. East Coast, from New Jersey to Maine, in 2015 and 2016. Samples were collected from shore or small boat by hand using clean sampling techniques and processed within 12 hours of collection. Salinity and temperature were also measured, using a hand-held YSI sonde. Water was filtered using either quartz filters combusted at 550 degrees C and 0.2 µm polycarbonate filters cleaned with 2% hydrochloric acid (2016) or sequentially filtered using 20 µm nylon filters and 0.2 µm polycarbonate filters cleaned with 2% hydrochloric acid (2015). The sequential filters in 2015 can be summed to calculate a bulk sample. The filters were stored frozen until analysis for particulate HgT and MeHg, and ancillary parameters. Dissolved samples were collected after the filter (filtrate) into acid cleaned iChem bottles and preserved with 0.2% HCl if intended for HgT or combined MeHg and HgT analyses. Samples for only dissolved MeHg were preserved with 0.5% H 2 SO 4 . DOC samples were collected from the particulate Hg filtrate into muffled amber vials and nutrient samples into acid-cleaned plastic centrifuge tubes; both were preserved by freezing. Samples were collected at various tidal stages (as explained above in Description section). Particulate and dissolved MeHg samples were analyzed on a Tekran 2700 Automated Methylmercury Analysis System following standard techniques (Hammerschmidt and Fitzgerald, 2006; Gosnell et al., 2017; Munson et al., 2014; Seelen et al., 2021). Briefly, particulate samples were digested in 4.5N nitric acid overnight, neutralized with potassium hydroxide and acetate buffer, and ethylated using sodium tetraethylborate before separation by gas chromatography and cold vapor atomic fluorescence detection with calibration against a standard curve (Alfa Aesar CAS: 115–09–3, LOT: 1791821 spike recovery= 103±14%). Dissolved MeHg samples were analyzed similarly except the seawater was digested overnight in 1% H 2 SO 4 , and 2.5% L-ascorbic acid was added prior to ethylation (Munson et al., 2014) (Alfa Aesar CAS: 115–09–3, LOT: 1791821 spike recovery= 86±34%). The samples were not corrected for spike recovery. The methods are a modified version of EPA method 1630. HgT was analyzed on a Tekran 2600 by cold vapor atomic fluorescence spectrometry following EPA method 1631, refined by Hammerschmidt and Fitzgerald (2006). The particulate HgT (pHgT) sample filters were digested in 4.5N nitric acid with bromine monochloride (BrCl) for 16 hrs, followed by hydroxylamine hydrochloride and stannous chloride additions before analysis. Calibration was against a standard curve and the results were spike corrected (J.T.Baker CAS: 7732–16–5, Batch No: 0000127949 spike recovery= 121±2%). For some samples, the same filter was used for both pMeHg and pHgT, in which case the BrCl addition was made after the MeHg analysis was complete. Dissolved HgT (dHgT) analysis was similar to the particulate analysis, except only BrCl was added >16 hr for digestion prior to reduction for analysis. The samples were blank and spike corrected (J.T.Baker CAS: 7732–16–5, Batch No: 0000127949 spike recovery= 76±5%). Total suspended solids (TSS) was determined using the dried filters, as they were pre-weighed prior to use. Chlorophyll a (chl a) and phaeopigment (pha) concentrations were quantified from wet filters using fluorescence techniques after 90% acetone extraction and acidification for pha. DOC was analyzed on a Shimadzu TOC/TN analyzer. Duplicate average RSD = 6.6% (pigments) and 2.8% (DOC); Seelen et al., 2021; Taylor et al., 2019). Details of filtering and other analytical methods can be found in Seelen et al. (2021) and other publications covering these studies (Taylor et al., 2019; Seelen et al., 2018). Blanks and replicate samples were included in the sampling and analysis, and spike recoveries and other QA/QC included in the analysis (see in Supplemental Files below). |
| Availability date: | |
| Metadata version: | 1 |
| Keydate: | 2024-04-19 17:22:01+00 |
| Editdate: | 2024-04-19 17:22:42+00 |