Dataset: Water column production and respiration 2017
Deployment: PE17-18

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/896385

Principal Investigator:

John Lehrter (University of South Alabama; and Dauphin Island Sea Lab, USA-DISL)

Student:

Mai Fung (University of South Alabama; and Dauphin Island Sea Lab, USA-DISL)

Alexis Hagemeyer (University of South Alabama; and Dauphin Island Sea Lab, USA-DISL)

BCO-DMO Data Manager:

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

Project:

Collaborative Research: A RAPID response to Hurricane Harvey's impacts on coastal carbon cycle, metabolic balance and ocean acidification (HarveyCarbonCycle)

Version:

Deployment Synonyms:

GOM_UW_1704, GOM_CTD_1704

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Description

Methods & Sampling

Dataset acquisition description

Samples for plankton community respiration (WR) measurements were collected from several depths in the water column including the surface layer, the bottom layer, the layer at depth of chlorophyll maximum, midwater oxygen maximum, and midwater oxygen minimum. For each sample collected, three transparent (light) glass bottles and three dark glass bottles were filled directly from the ship's Niskin bottle array (Murrell and Lehrter, 2011). Aliquots were put into acid-cleaned 300 milliliter BOD (biochemical oxygen demand) bottles for light-dark incubation experiments. After initial O₂ measurements were taken (T0), samples were placed in a darkened incubator that maintained surface water temperatures using water supplied continuously from the ship’s hull pump. Light bottle treatments were incubated in an outdoor incubator with screening that reduced ambient light by 50%. Dark bottle treatments were also placed in the outdoor incubator but were kept dark by their black liners and caps.

For more detailed methods see Murrell et al. (2013) and Murrell and Lehrter (2011).

Concentrations of O₂ were measured initially and after 24 hours using a Hach or YSI oxygen sensor and temperature probe. Salinity values for each sample were obtained from the ship's CTD (SeaBird 911). Net primary production rates were calculated as the change in O₂ over time in light bottles screened at 50% of ambient sunlight and incubated for 24 hours, expressed in units of millimoles oxygen per cubic meter per day (mmol O₂ m^-3 d^-1). Respiration rates were calculated as the change in O₂ over time in dark bottles incubated for 24 hours, expressed in units of millimoles oxygen per cubic meter per day (mmol O₂ m^-3 d^-1).

Problem report: Some of the incubation bottles had their caps come off during incubations. These values are labeled as NAN (not a number) in the dataset.

Note: Dissolved oxygen data were recorded in mg/L for the April 2017 cruise and in percent saturation for the July and September cruises.

Data Processing Description

Dataset Processing Description

Please see the Supplemental Files section for equations in more easily readable format, along with a brief summary of the method for light and dark bottle oxygen assay to measure primary production and respiration

Net primary production, respiration, and gross primary production calculations
Rates were adjusted to initial temperatures using the Arrhenius equation and initial and final temperatures.

Variables:

NPP is Net Primary Production
R is Respiration
GPP is Gross Primary Production
NPP_T is Temperature adjusted net primary production
R_T is Temperature adjusted respiration
GPP_T is Temperature adjusted gross primary production
DO_Light is the dissolved oxygen concentration in the light bottles
DO_Dark is the dissolved oxygen concentration in the dark bottles
TF = time final
T0 = time initial

Equations: (see Supplemental Files section)
NPP = (DO_Light_TF - DO_Light_T0)/(TF - T0)
R = (DO_Dark_TF - DO_Dark_T0)/(TF - T0)
GPP = NPP - R
NPP_T = NPP*2^((T_T0 - T_TF)./10)
R_T = R*2^((T_T0 - T_TF)./10)
GPP_T = GPP*2^((T_T0 - T_TF)./10)

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1760747	NSF Division of Ocean Sciences

Instruments

CTD Sea-Bird 911

Supplied Name: CTD Seabird 911

Supplied Description:

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.

Niskin bottle

Supplied Description:

Samples were collected from several depths in the water column using Niskin bottles

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.

Oxygen Sensor

Supplied Name: O2 probe with thermometer (Hach or YSI)

Supplied Description:

Concentrations of O2 were measured initially and after 24 hours using a Hach or YSI oxygen sensor and temperature probe.

Instrument Type

Generic Name: Oxygen Sensor

Acronym: Dissolved Oxygen Sensor

Generic Description:

An electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise	Cruise identification	unitless	cruise_id
Station	Station identification	unitless	station
Layer	Depth layer of water sample where S=surface, B=bottom, Chla max=midwater chlorophyll a maximum layer, O2 max=midwater oxygen maximum, or O2 min=midwater oxygen minimum	unitless	site_descrip
Latitude	Latitude of sample collection	decimal degrees	lat
Longitude	Longitude of sample collection	decimal degrees	lon
Sample_Collection_Date_Time	Date and time of sample collection in UTC	unitless	ISO_DateTime_UTC
Depth_Bottom	Depth of the bottom	meters	depth_bottom
Bottle_Number	Sample bottle number from Niskin bottle array	unitless	bottle
Bottle_sampling_depth	Sampling depth of Niskin bottle	meters	depth
Salinity	Salinity from CTD sensor	psu	sal
DO_Light_1_T0	Initial dissolved oxygen concentration in Light bottle replicate 1	milligram per liter (mg/L) or percent saturation	O2
DO_Light_2_T0	Initial dissolved oxygen concentration in Light bottle replicate 2	milligram per liter (mg/L) or percent saturation	O2
DO_Light_3_T0	Initial dissolved oxygen concentration in Light bottle replicate 3	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_1_T0	Initial dissolved oxygen concentration in Dark bottle replicate 1	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_2_T0	Initial dissolved oxygen concentration in Dark bottle replicate 2	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_3_T0	Initial dissolved oxygen concentration in Dark bottle replicate 3	milligram per liter (mg/L) or percent saturation	O2
T_Light_1_T0	Initial temperature of Light bottle replicate 1	degrees Celsius	temperature
T_Light_2_T0	Initial temperature of Light bottle replicate 2	degrees Celsius	temperature
T_Light_3_T0	Initial temperature of Light bottle replicate 3	degrees Celsius	temperature
T_Dark_1_T0	Initial temperature of Dark bottle replicate 1	degrees Celsius	temperature
T_Dark_2_T0	Initial temperature of Dark bottle replicate 2	degrees Celsius	temperature
T_Dark_3_T0	Initial temperature of Dark bottle replicate 3	degrees Celsius	temperature
DO_Light_1_TF	Final dissolved oxygen concentration in Light bottle replicate 1	milligram per liter (mg/L) or percent saturation	O2
DO_Light_2_TF	Final dissolved oxygen concentration in Light bottle replicate 2	milligram per liter (mg/L) or percent saturation	O2
DO_Light_3_TF	Final dissolved oxygen concentration in Light bottle replicate 3	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_1_TF	Final dissolved oxygen concentration in Dark bottle replicate 1	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_2_TF	Final dissolved oxygen concentration in Dark bottle replicate 2	milligram per liter (mg/L) or percent saturation	O2
DO_Dark_3_TF	Final dissolved oxygen concentration in Dark bottle replicate 3	milligram per liter (mg/L) or percent saturation	O2
T_Light_1_TF	Final temperature of Light bottle replicate 1	degrees Celsius	temperature
T_Light_2_TF	Final temperature of Light bottle replicate 2	degrees Celsius	temperature
T_Light_3_TF	Final temperature of Light bottle replicate 3	degrees Celsius	temperature
T_Dark_1_TF	Final temperature of Dark bottle replicate 1	degrees Celsius	temperature
T_Dark_2_TF	Final temperature of Dark bottle replicate 2	degrees Celsius	temperature
T_Dark_3_TF	Final temperature of Dark bottle replicate 3	degrees Celsius	temperature
CruiseStation	Concatenated Cruise and Station	unitless	site
Time_in_local	Incubation start time (local) when bottles were placed in the on-deck incubator	unitless	DateTime
Time_out_local	Incubation end time (local) when bottles were taken out of the on-deck incubator	unitless	DateTime

Database

Contribute Data

Dataset: Water column production and respiration 2017
Deployment: PE17-18

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Water column production and respiration 2017Deployment: PE17-18

Dataset acquisition description

Dataset Processing Description

Dataset: Water column production and respiration 2017
Deployment: PE17-18