Dataset: BATS primary production
Deployment: BATS_cruises

BATS primary production

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/893182

Principal Investigator:

Nicholas Bates (Bermuda Institute of Ocean Sciences, BIOS)

Co-Principal Investigator:

Rodney J. Johnson (Bermuda Institute of Ocean Sciences, BIOS)

Scientist:

Paul J. Lethaby (Bermuda Institute of Ocean Sciences, BIOS)

Claire Medley (Bermuda Institute of Ocean Sciences, BIOS)

Data Manager:

Dominic Smith (Bermuda Institute of Ocean Sciences, BIOS)

BCO-DMO Data Manager:

Dana Stuart Gerlach (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Audrey Mickle (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Bermuda Atlantic Time-series Study (BATS)

Version:

Deployment Synonyms:

Bermuda Atlantic Time-series Study cruises

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Description

Methods & Sampling

Dataset acquisition description

Primary production is measured in situ as part of the monthly Bermuda Atlantic Time Series (BATS) cruises.

Scope and field of application
Primary production is a fundamental ecological variable for understanding the flow of energy into an ecosystem as it supports the availability of organic material as building blocks for higher trophic levels. This method uses a radiocarbon ¹⁴C spike and liquid scintillation counter (LSC) techniques to quantify the rate of primary production. This procedure describes the method for the determination of primary production in seawater, expressed as milligrams of carbon per cubic meter per day (mg C m⁻³day⁻¹) . This method is suitable for the assay of all levels of primary production found in the ocean.

Primary production is defined as the rate of uptake of inorganic carbon (DIC) into particulate organic carbon (POC),

DIC_n * POC¹⁴C * 1.05
C uptake = ----------------------------- , where
DIC¹⁴C

C uptake = rate of carbon fixation (mg Carbon m⁻³day⁻¹)
DIC_n = naturally occurring dissolved inorganic carbon
POC¹⁴C = ¹⁴C spiked particulate organic carbon
DIC¹⁴C = ¹⁴C spiked dissolved inorganic carbon
1.05 = metabolic discrimination factor due to biological isotopic fractionation (preferable uptake of lighter isotopes)

Principle of analysis
The rate of carbon fixation by autotrophs in seawater is measured by tracing the uptake of radioactive ¹⁴C from the inorganic form to the particulate organic form. Radiocarbon is added at an assumed ratio to the total inorganic carbon content of the seawater sample. The uptake of radiocarbon by the particulate phytoplankton is converted to total carbon uptake by the application of this radiocarbon: total carbon ratio. Inorganic carbon is not measured because samples are acidified before analysis. The seawater is collected using the CTD at discrete depths every 20 meters from the surface to 140 meters. The radioactive ¹⁴C spike is added and samples are incubated in situ at their respective depths using a free-floating array. The array is deployed prior to first light and recovered after sunset to capture the dawn to dusk light cycle.

A liquid scintillation counter (LSC) is used to calculate the level of radioactivity in the sample and therefore the amount of ¹⁴C particulate organic carbon. The LSC measures the conversion of radioactive decay events into photons of light, which are detected by photomultiplier tubes and converted into electrical pulses. In order to aid the detection of radioactivity, a liquid scintillation cocktail is added (Ultima gold for this method). The cocktail contains both solvent and scintillator molecules. The radioactive decay from the ¹⁴C excites the solvent molecule, and the energy is transferred to the scintillator which re-emits the energy in the form of light. Often more than one type of scintillator is present in the cocktail to allow for the emission of light at a suitable wavelength to be detected by the photomultiplier tubes. The resulting electrical signal that is generated is recorded as counts per minute (CPM).

Field sampling

Samples for primary production are collected two hours before dawn (pre-dawn production cast) and no other samples are taken during this cast. Nitrile gloves are used during the handling of samples. The polycarbonate incubation bottles are filled directly from the Niskins under low light conditions. Each bottle is rinsed 3 times before filling. Five bottles are filled for each sample depth. 250 µl of the ¹⁴C working solution is added to each of the five bottles in the shared use radioisotope lab container. Low light levels are maintained by using red lights in the lab. One of the five bottles is wrapped in electrical tape; this bottle is then wrapped in aluminium foil to ensure it is kept in dark conditions. One of the five productivity bottles is used as the time-zero (T-0) sample. The spike is added, the sample is then thoroughly shaken before 50 ml is filtered. A 250 µl aliquot -- to be used for counting total added ¹⁴C activity -- is removed from each of the T-0 bottles and is placed in a 20 ml glass scintillation vial containing 250 µl ethanolamine.

Approximately one hour before sunrise the productivity array is deployed. The incubation occurs throughout the day and the array is recovered approximately half an hour after sunset. Upon recovery and under low light conditions, a 50 ml aliquot is withdrawn from each productivity bottle and filtered onto a 25 mm Whatman® Glass Fibre Filter, maintaining vacuum levels of 70 mm Hg or less. Neither the filter nor the syringe is rinsed. The filter is placed into a 20 ml glass scintillation vial. Under a fume hood, excess radioactive carbon is driven off by adding 250 µl 0.5 N hydrochloric acid. A 250 µl aliquot for counting total added ¹⁴C activity (Time End Specific Activity) is removed from one of the light productivity bottles. This is placed in a 20 ml glass scintillation vial containing 250 µl ethanolamine (Sigma), similar to the T-0 described in Time Zero Specific Activity Sample. The samples are then stored at room temperature until analysis.

For additional details, please see Protocols for the Bermuda Atlantic Time-series Study Core Measurements.

Data Processing Description

Dataset Processing Description

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0752366	NSF Division of Ocean Sciences
OCE-1756105	NSF Division of Ocean Sciences
OCE-2241455	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird 911

Supplied Name: CTD

Supplied Description:

The seawater is collected using the CTD at discrete depths every 20 meters from the surface to 140 meters.

Instrument Type

Generic Name: CTD Sea-Bird 911

Acronym: CTD SBE 911

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0035/

Generic Description:

The Sea-Bird SBE 911 is a type of CTD instrument package. The SBE 911 includes the SBE 9 Underwater Unit and the SBE 11 Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 and SBE 11 is called a SBE 911. The SBE 9 uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 and SBE 4). The SBE 9 CTD can be configured with auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). More information from Sea-Bird Electronics.

Light-Dark Bottle

Supplied Name: light and dark incubation bottles

Supplied Description:

Seawater samples were collected prior to sunrise, separated into three light bottles and one dark bottle, and a radioactive 14C tracer added. The bottles were then deployed on an incubation array at their collection depths, and allowed to drift on the array for the full light day.

Instrument Type

Generic Name: Light-Dark Bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/82/

Generic Description:

The light/dark bottle is a way of measuring primary production by comparing before and after concentrations of dissolved oxygen.

Bottles containing seawater samples with phytoplankton are incubated for a predetermined period of time under light and dark conditions. Incubation is preferably carried out in situ, at the depth from which the samples were collected. Alternatively, the light and dark bottles are incubated in a water trough on deck, and neutral density filters are used to approximate the light conditions at the collection depth.

Rates of net and gross photosynthesis and respiration can be determined from measurements of dissolved oxygen concentration in the sample bottles.

Liquid Scintillation Counter

Supplied Description:

A Liquid Scintillation Counter is used to calculate the level of radioactivity in the sample and therefore the amount of 14C particulate organic carbon

Instrument Type

Generic Name: Liquid Scintillation Counter

Acronym: LSC

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB21/

Generic Description:

Liquid scintillation counting is an analytical technique which is defined by the incorporation of the radiolabeled analyte into uniform distribution with a liquid chemical medium capable of converting the kinetic energy of nuclear emissions into light energy. Although the liquid scintillation counter is a sophisticated laboratory counting system used the quantify the activity of particulate emitting (ß and a) radioactive samples, it can also detect the auger electrons emitted from 51Cr and 125I samples.

Liquid scintillation counters are instruments assaying alpha and beta radiation by quantitative detection of visible light produced by the passage of rays or particles through a suitable scintillant incorporated into the sample.

Niskin bottle

Supplied Description:

Instrument Type

Generic Name: Niskin bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/

Generic Description:

A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
ID	A unique bottle ID which identifies cruise, cast, and Niskin number	unitless	sample
ISO_DateTime_UTC_in	Datetime productivity array was deployed in ISO8601 format	unitless	ISO_DateTime_UTC
ISO_DateTime_UTC_out	Datetime productivity array was recovered in ISO8601 format	unitless	ISO_DateTime_UTC
Vessel	Name of vessel used for cruise	unitless	ship
Latitude_in	Latitude productivity array was deployed in decimal degrees, South is negative	decimal degrees	lat
Longitude_in	Longitude productivity array was deployed in decimal degrees, West is negative	decimal degrees	lon
Latitude_out	Latitude productivity array was recovered in decimal degrees, South is negative	decimal degrees	lat
Longitude_out	Longitude productivity array was recovered in decimal degrees, West is negative	decimal degrees	lon
Cruise_type	Cruise type (BATS Core, Bloom A, or Bloom B)	unitless	cruise_type
Cruise_num	BATS Cruise number	unitless	cruise_id
Cast_type	Cast type (CTD or Hydrocast)	unitless	cast_type
Cast_num	Cast Number (1-80 = CTD, 81-99 = Hydrocast)	unitless	cast
Bottle_num	Niskin bottle number	unitless	bot_Nis
QF_Niskin_GoFlo	Niskin/GoFlo quality flag (-3 = suspect, 1=unverified, 2= verified/acceptable)	unitless	q_flag
Depth	Collection depth	meters (m)	depth
QF1_Depth	Quality control flag for depth; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
Pressure	Pressure (dbar) from CTD	units	press
QF2_Pressure	Quality control flag for pressure; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
Temp	CTD temp (C)	units	temp
QF3_Temp	Quality control flag for temperature; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
Sal	Salinity from Goflo bottle or CTD	units	sal
QF4_Sal	Quality control flag for salinity; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
lt1	14C Primary Production light bottle #1	mgC/m^3/day	PP
QF5_it1	Quality control flag for 14C Primary Production light bottle #1; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
lt2	14C Primary Production light bottle #2	mgC/m^3/day	PP
QF6_lt2	Quality control flag for 14C Primary Production light bottle #2; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
lt3	14C Primary Production light bottle #3	mgC/m^3/day	PP
QF7_lt3	Quality control flag for 14C Primary Production light bottle #3; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
dark	14C Primary Production dark bottle	mgC/m^3/day	PP
QF8_dark	Quality control flag for 14C Primary Production dark bottle; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
t0	14C Primary Production Time zero	mgC/m^3/day	PP
QF9_t0	Quality control flag for 14C Primary Production Time zero; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
pp	Primary Production Mean Light values - Dark value	mgC/m^3/day	PP
QF10_pp	Quality control flag for Mean Light values - Dark value; Parameter quality flags defined as 1= unverified, 2= verified acceptable, 3= questionable, 4= bad, 9= no data	unitless	q_flag
yyyymmdd_in	Year, month, and day productivity array was deployed in YYYYMMDD format	unitless	start_date
yyyymmdd_out	Year, month, and day productivity array was recovered in YYYYMMDD format	unitless	end_date
decy_in	Date productivity array was deployed in Decimal Year format	unitless	year_decimal
decy_out	Date productivity array was recovered in Decimal Year format	unitless	year_decimal
Time_in	Time productivity array was deployed in HHMM format	unitless	time
Time_out	Time productivity array was recovered in HHMM format	unitless	time
Date	Date productivity array was deployed in YYYY-MM-DD format	unitless	date

Database

Contribute Data

Dataset: BATS primary production
Deployment: BATS_cruises

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: BATS primary productionDeployment: BATS_cruises

Dataset acquisition description

Dataset Processing Description

Dataset: BATS primary production
Deployment: BATS_cruises