Metadata Report for BODC Series Reference Number 1699322

Metadata Summary

Data Description

Data Category Water sample data
Instrument Type
Niskin bottle  discrete water samplers
Instrument Mounting lowered unmanned submersible
Originating Country United Kingdom
Originator Dr Ken Jones
Originating Organization Dunstaffnage Marine Laboratory (now Scottish Association for Marine Science)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) LOIS Shelf Edge Study (LOIS - SES)

Data Identifiers

Originator's Identifier CH125B_CTD_PIGX_59:CP112
BODC Series Reference 1699322

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1996-02-25 03:11
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval -

Spatial Co-ordinates

Latitude 56.45909 N ( 56° 27.5' N )
Longitude 9.08267 W ( 9° 5.0' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 3.6 m
Maximum Sensor or Sampling Depth 60.1 m
Minimum Sensor or Sampling Height 362.8 m
Maximum Sensor or Sampling Height 419.3 m
Sea Floor Depth 422.9 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Unspecified -
Sensor or Sampling Depth Datum Unspecified -
Sea Floor Depth Datum Unspecified -


BODC CODERankUnitsTitle
ADEPZZ011MetresDepth below surface of the water body
BOTTFLAG1DimensionlessSampling process quality flag (BODC C22)
CPHLFLP11Milligrams per cubic metreConcentration of chlorophyll-a {chl-a CAS 479-61-8} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry
PHAEFLP11Milligrams per cubic metreConcentration of phaeopigments {pheopigments} per unit volume of the water body [particulate >GF/F phase] by filtration, acetone extraction and fluorometry
SAMPRFNM1DimensionlessSample reference number

Definition of BOTTFLAG

0The sampling event occurred without any incident being reported to BODC.
1The filter in an in-situ sampling pump physically ruptured during sample resulting in an unquantifiable loss of sampled material.
2Analytical evidence (e.g. surface water salinity measured on a sample collected at depth) indicates that the water sample has been contaminated by water from depths other than the depths of sampling.
3The feedback indicator on the deck unit reported that the bottle closure command had failed. General Oceanics deck units used on NERC vessels in the 80s and 90s were renowned for reporting misfires when the bottle had been closed. This flag is also suitable for when a trigger command is mistakenly sent to a bottle that has previously been fired.
4During the sampling deployment the bottle was fired in an order other than incrementing rosette position. Indicative of the potential for errors in the assignment of bottle firing depth, especially with General Oceanics rosettes.
5Water was reported to be escaping from the bottle as the rosette was being recovered.
6The bottle seals were observed to be incorrectly seated and the bottle was only part full of water on recovery.
7Either the bottle was found to contain no sample on recovery or there was no bottle fitted to the rosette position fired (but SBE35 record may exist).
8There is reason to doubt the accuracy of the sampling depth associated with the sample.
9The bottle air vent had not been closed prior to deployment giving rise to a risk of sample contamination through leakage.

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.


Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles have a capacity between 1.7 and 30 L, while Lever Action bottles have a capacity between 1.7 and 12 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

Pigments for Charles Darwin and RRS Challenger cruises

Document History

Converted from CDROM documentation.

Content of data series

CPHLFLP1 Fluorometric chlorophyll-a
Fluorometric assay of acetone extract (GF/F filtered)
Milligrams/cubic metre
CPHLFLP4 Fluorometric chlorophyll-a
Fluorometric assay of acetone extraction (sum of size fractions >0.2 microns)
Milligrams/cubic metre
CPHLPR01 CTD chlorophyll
Calibrated in-situ fluorometer
Milligrams/cubic metre
PHAEFLP1 Fluorometric phaeopigments
Fluorometric assay of acetone extract (GF/F filtered)
Milligrams/cubic metre
SCHLFLPF Size-fractionated fluorometric chlorophyll-a
Fluorometric assay of an acetone extract (0.2-2µm size fraction)
Milligrams/cubic metre
SCHLFLPG Size-fractionated fluorometric chlorophyll-a
Fluorometric assay of an acetone extract (2-20µm size fraction)
Milligrams/cubic metre
SCHLFLPQ Size-fractionated fluorometric chlorophyll-a
Fluorometric assay of an acetone extract (>20µm size fraction)
Milligrams/cubic metre

Data Originator

Dr Ken Jones, CCMS Dunstaffnage Marine Laboratory, UK.

Sampling strategy and methodology

Charles Darwin cruises CD91B, CD93A and CD93B and RRS Challenger cruises CH121A, CH121B, CH121C, CH123A, CH123B, CH125A, CH125B, CH126A, CH126B, CH128A and CH128B.

Samples were collected from either the non-toxic surface sea water supply or from Niskin bottles fitted to the CTD rosette. They were taken in Nalgene bottles, rinsed twice with sample water prior to filling.

The samples were vacuum filtered through 2.5 cm GF/F filters. The volume of water filtered varied depending on the particulate load in the sample. The filters were folded and immediately frozen.

Back in the laboratory, the filters were extracted into 8 ml of 90% neutralised acetone and stored for between 18 and 36 hours in a refrigerator. The extracts were centrifuged at 3000 rpm for two 5-minute bursts.

The resulting chlorophyll solutions were assayed on a bench fluorometer. Three drops of 8% HCl were added and the assay was repeated. Chlorophyll-a and phaeopigment concentrations were determined from the two fluorometer readings using the equations in Tett and Grantham (1978).


Tett P. and Grantham B. 1978. A simple guide to the measurement and interpretation of chlorophyll concentration, temperature and salinity, in coastal waters. SMBA. 85pp.

Project Information

LOIS Shelf Edge Study (LOIS - SES)


SES was a component of the NERC Land Ocean Interaction Study (LOIS) Community Research Programme that made intensive measurements from the shelf break in the region known as the Hebridean Slope from March 1995 to September 1996.

Scientific Rationale

SES was devoted to the study of interactions between the shelf seas and the open ocean. The specific objectives of the project were:


The SES fieldwork was focussed on a box enclosing two sections across the shelf break at 56.4-56.5 °N and 56.6-56.7 °N. Moored instrument arrays were maintained throughout the experiment at stations with water depths ranging from 140 m to 1500 m, although there were heavy losses due to the intensive fishing activity in the area. The moorings included meteorological buoys, current meters, transmissometers, fluorometers, nutrient analysers (but these never returned any usable data), thermistor chains, colour sensors and sediment traps.

The moorings were serviced by research cruises at approximately three-monthly intervals. In addition to the mooring work this cruises undertook intensive CTD, water bottle and benthic surveys with cruise durations of up to 6 weeks (3 legs of approximately 2 weeks each).

Moored instrument activities associated with SES comprised current measurements in the North Channel in 1993 and the Tiree Passage from 1995-1996. These provided boundary conditions for SES modelling activities.

Additional data were provided through cruises undertaken by the Defence Evaluation and Research Agency (DERA) in a co-operative programme known as SESAME.

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1996-02-25
End Date (yyyy-mm-dd) 1996-02-25
Organization Undertaking ActivityUniversity of Wales, Bangor School of Ocean Sciences (now Bangor University School of Ocean Sciences)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierCH125B_CTD_CP112
Platform Categorylowered unmanned submersible

BODC Sample Metadata Report for CH125B_CTD_CP112

Sample reference number Nominal collection volume(l) Bottle rosette position Bottle firing sequence number Minimum pressure sampled (dbar) Maximum pressure sampled (dbar) Depth of sampling point (m) Bottle type Sample quality flag Bottle reference Comments
80428   10.00      204.60  206.00  199.30 Niskin bottle No problem reported    
80429   10.00       63.90   65.40   60.10 Niskin bottle No problem reported    
80846   10.00      408.70  412.60  402.50 Niskin bottle No problem reported    
80848   10.00        7.10    8.30    3.60 Niskin bottle No problem reported    

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.


Cruise Name CH125B
Departure Date 1996-02-13
Arrival Date 1996-03-03
Principal Scientist(s)A Edward Hill (University of Wales, Bangor School of Ocean Sciences)
Ship RRS Challenger

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain
Q value below limit of quantification