Dataset: Suspended particle total mercury and monomethylmercury in the California Current Ecosystem (CCE)

Name: Suspended particle total mercury and monomethylmercury in the California Current Ecosystem (CCE) determined from samples collected on R/V Roger Revelle cruise RR2105 (P2107) in July to August 2021
Published: 2024-05-14
Keywords: mercury, particles, CCE, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.926959.1

Spatial Extent: N:36.52 E:-120.53 S:34.47 W:-130.56

Central California coast/upwelling and offshore

Temporal Extent: 2021-07-17 - 2021-08-09

Project:

California Current Ecosystem Long Term Ecological Research site (CCE LTER)

Collaborative Proposal: Unravelling the Oceanic Dimethylmercury Cycle (DMHg in the Ocean)

Program:

Ocean Carbon and Biogeochemistry (OCB)

Long Term Ecological Research network (LTER)

Principal Investigator:

Carl Lamborg (University of California-Santa Cruz, UCSC)

Amina T. Schartup (University of California-San Diego, UCSD-SIO)

Student:

Hannah M. Adams (University of California-San Diego, UCSD-SIO)

Xinyun Cui (University of California-Santa Cruz, UCSC)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-05-14

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Suspended particle total mercury and monomethylmercury in the California Current Ecosystem (CCE) determined from samples collected on R/V Roger Revelle cruise RR2105 (P2107) in July to August 2021

Abstract:

This dataset includes concentrations of suspended particulate total mercury and monomethylmercury from 8 upwelling stations and 5 offshore stations (13 stations in total, 2-4 depths per station), during the 2021 CCE LTER Process Cruise (P2107), from July 17th to Aug 9th. Suspended particle samples (1 and 51 micrometers (µm)) were collected with a multiple-unit large-volume in situ filtration system. Sampling depths were from the surface (10 meters) to the deep ocean as deep as 1000 meters.

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2024-05-14	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.926959.1	2024-05-14

Methods & Sampling

Suspended particles were collected using McLane Research in-situ pumps (WTS-LV) using modified, two-layer filter holders. The top filter holder layer was loaded with a 51-micrometer (μm) polyester mesh filter to collect large-size fraction particles (LSF). The other filter holder layer was loaded with a pre-combusted GF/F glass microfiber filter (Whatman) to collect small-size fraction particles (SSF, 1-51 μm). Filter holders were acid-leached before use, and GF/F filters were additionally combusted at 450 degrees Celsius (°C) for 4 hours. Sinking particles were collected by sediment traps.

Total mercury (THg) and monomethylmercury (MMHg) in suspended and sinking particles were determined by digesting filter portions in nitric acid (2N, trace mental grade, Fisher) for 4 hours at 60°C constant water bath with intermittent sonication. For THg determination, digestates were oxidized with bromine monochloride for at least 2 hours and pre-reduced with hydroxylamine hydrochloride. Subsamples were then reduced with stannous chloride, and the evolved Hg0 concentrations were determined by dual gold amalgamation cold vapor atomic fluorescence spectrometry (CVAFS) with a Tekran 2600 against both gaseous Hg0 and aqueous Hg2+ standards. MMHg determination used a direct ethylation method. Digestates were treated with ascorbic acid, buffered with acetate, and neutralized with potassium hydroxide (KOH; 45%) to pH between 4 and 5. Sodium tetraethylborate (1%, in 2% KOH) was added in digestates reacting for 20 minutes prior to analysis by CVAFS. The method detection limits for THg and MMHg were 26.5 femtomolar (fM) and 3.3 fM in the SSF, and 0.75 fM and 0.24 fM in the LSF, respectively.

For carbon (C) mass determination in the SSF and LSF, filters were packed into a tin capsule and analyzed for particulate carbon mass and measured using Carlo Erba 1108 elemental analyzer coupled to a Thermo Finningan Delta Plus XP IRMS at University of California, Santa Cruz. The analytical precision of C % is 0.65% in the SSF and 1.1% in the LSF based on the organic standards IU Acetanilide and USGC41.

Data Processing Description

Microsoft Excel was used for data processing.

We used the GEOTRACES Quality Flag Policy to reflect our data quality:
"1" represents good value;
"4" represents bad value due to errors in sampling;
"6" represents data value below the instrument detection limit;
"9" represents missing data / no data value.

BCO-DMO Processing

- Imported original file "P2107_Part_Hg_BCODMO.xlsx" into the BCO-DMO system.
- Marked "n/a" as a missing data value (missing data are empty/blank in the final CSV file).
- Renamed fields to comply with BCO-DMO naming conventions.
- Created date-time fields in ISO8601 format in local and UTC time zones.
- Saved the final file as "926959_v1_suspended_partic_totalhg_and_monomethylhg_cce.csv".

Data Files

File
926959_v1_suspended_partic_totalhg_and_monomethylhg_cce.csv (Comma Separated Values (.csv), 5.71 KB) MD5:a8ad76c2ab4be81a522990684590bc98 Primary data file for dataset ID 926959, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-2023046
NSF Division of Ocean Sciences	OCE-1637632

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
RR2105	CCE LTER III P2107	2021-07-13	R/V Roger Revelle	Michael R. Stukel (Chief Scientist)	data info

Instruments

Carlo-Erba EA-1108 elemental analyzer

Supplied Name: Carlo Erba 1108 elemental analyzer

Supplied Description:

Instrument Type

Generic Name: Carlo-Erba EA-1108 elemental analyzer

Acronym: Carlo-Erba EA 1108

Generic Description:

An elemental analyzer that simultaneously determines the total carbon, hydrogen, nitrogen, and sulfur in a small solid or liquid sample. A sample is put into a tin capsule that is placed in the combustion tube. Here, the sample is in an oxygen-rich gas stream, which causes flash combustion of the tin capsule, and in turn, the sample is rapidly combusted. The resulting gases are separated on a packed gas chromatography column and quantified using a thermal conductivity detector. The instrument was originally manufactured by Carlo-Erba, which has since been replaced by Thermo Scientific (part of Thermo Fisher Scientific). This model is no longer in production. It is also possible to determine oxygen with a modification to the systems configuration. Analysis times: CHN in 7 min, S in 5 min and O in 6 min. Range: 10 ppm to 100%.

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo Finningan Delta Plus XP IRMS

Supplied Description:

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

McLane Large Volume Pumping System WTS-LV

Supplied Name: McLane Research in-situ pumps (WTS-LV)

Supplied Description:

Instrument Type

Generic Name: McLane Large Volume Pumping System WTS-LV

Acronym: WTS-LV

Generic Description:

The WTS-LV is a Water Transfer System (WTS) Large Volume (LV) pumping instrument designed and manufactured by McLane Research Labs (Falmouth, MA, USA). It is a large-volume, single-event sampler that collects suspended and dissolved particulate samples in situ.

Ambient water is drawn through a modular filter holder onto a 142-millimeter (mm) membrane without passing through the pump. The standard two-tier filter holder provides prefiltering and size fractioning. Collection targets include chlorophyll maximum, particulate trace metals, and phytoplankton. It features different flow rates and filter porosity to support a range of specimen collection. Sampling can be programmed to start at a scheduled time or begin with a countdown delay. It also features a dynamic pump speed algorithm that adjusts flow to protect the sample as material accumulates on the filter. Several pump options range from 0.5 to 30 liters per minute, with a max volume of 2,500 to 36,000 liters depending on the pump and battery pack used. The standard model is depth rated to 5,500 meters, with a deeper 7,000-meter option available. The operating temperature is -4 to 35 degrees Celsius.

The WTS-LV is available in four different configurations: Standard, Upright, Bore Hole, and Dual Filter Sampler. The high-capacity upright WTS-LV model provides three times the battery life of the standard model. The Bore-Hole WTS-LV is designed to fit through a narrow opening such as a 30-centimeter borehole. The dual filter WTS-LV features two vertical intake 142 mm filter holders to allow simultaneous filtering using two different porosities.

Tekran 2500 CVAFS mercury detector

Supplied Name: Cold vapor atomic fluorescence spectrometry (Tekran 2500/2600)

Supplied Description:

Instrument Type

Generic Name: Tekran 2500 CVAFS mercury detector

Generic Description:

Tekran 2500 Total Mercury Analysis System (not automated; cold vapor atomic fluorescence spectrometry)

Tekran 2600 Automated Total Mercury Analyzer series

Supplied Name: Cold vapor atomic fluorescence spectrometry (Tekran 2500/2600)

Supplied Description:

Instrument Type

Generic Name: Tekran 2600 Automated Total Mercury Analyzer series

Acronym: Tekran 2600

Generic Description:

The Tekran 2600 is a total Mercury (Hg) analysis system that can measure sub-picogram quantities of mercury in water, soil, vegetation, and other sample matrices. The system utilizes a Cold Vapour Atomic Fluorescence Spectroscopy (CVAFS) detector. The 2600-IVS (In-Vial Sparging) model is reconfigured for direct in-vial sparging sample introduction, and the 2600-NG (Natural Gas) model is designed for the analysis of gas phase sample cartridges. The system is capable of multiple method configurations: Dual stage gold preconcentration (EPA Method 1631); Direct measurement without preconcentration (EPA Method 245.7); Air sample analysis on gold traps (EPA Compendium Method IO-5); and Natural gas analysis on gold traps (ASTM D-6350, ISO 6978). It has a guaranteed minimum detection limit of < 0.05 nanograms per liter (ng/L). In clean room environments, with low mercury blanks, minimum detection limits as low as 0.02 ng/L are achievable.

See: https://www.tekran.com/products/laboratory/tekran-model-2600-automated-total-mercury-analysis-system/

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_ID	Cruise id; UNOLS cruise ID is RR2105	unitless	cruise_id
Cruise_Name	Cruise name	unitless	cruise_name
Station_Name	Name of the sampling station	unitless	station
ISO_DateTime_PDT	Sampling date and time in ISO 8601 format; time zone = PDT (UTC-7:00) Format: %Y-%m-%dT%H:%M	unitless	ISO_DateTime_Local
ISO_DateTime_UTC	Sampling date and time in ISO 8601 format; time zone = UTC Format: %Y-%m-%dT%H:%MZ	unitless	ISO_DateTime_UTC
Latitude	Station latitude, south is negative	decimal degrees	lat
Longitude	Station longitude, west is negative	decimal degrees	lon
Cast_Number	Cast number	unitless	cast
Depth_m	Sample depth	meters (m)	depth
tHg_CONC_SSF_fM	Concentrations of total mercury in small size fraction particle; limit of detection = 26	femtomolar (fM)	total_Hg
tHg_CONC_SSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	total_Hg
tHg_CONC_LSF_fM	Concentrations of total mercury in large size fraction particle; limit of detection = 0.75	femtomolar (fM)	total_Hg
tHg_CONC_LSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	total_Hg
MMHg_CONC_SSF_fM	Concentrations of total monomethylmercury in small size fraction particle; limit of detection = 3	femtomolar (fM)	MMHg
MMHg_CONC_SSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	MMHg
MMHg_CONC_LSF_fM	Concentrations of total monomethylmercury in large size fraction particle; limit of detection = 0.24	femtomolar (fM)	MMHg
MMHg_CONC_LSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	MMHg
Carbon_CONC_SSF_ug_L	Concentrations of total carbon in small size fraction particle	microgram per liter (ug/L)	C
Carbon_CONC_SSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	C
Carbon_CONC_LSF	Concentrations of total carbon in large size fraction particle	microgram per liter (ug/L)	C
Carbon_CONC_LSF_FLAG	Data flag, following the GEOTRACES Quality Flag Policy (see "Processing Description" for definitions)	unitless	C