Metadata Report for BODC Series Reference Number 1651526

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

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

Non-toxic (underway) sea water supply

A source of uncontaminated near-surface (commonly 3 to 7 m) seawater pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the non-toxic supply. The system is also referred to as the underway supply.

Chlorophyll-a measurements from non-toxic supply bottle samples collected during CROZET cruise D300

Originator's Protocol for Data Acquisition and Analysis

A total of 159 chlorophyll-a underway samples were taken from the non-toxic supply during the cruise and were analysed onboard.

The following methods have been taken from Venables et al. 2007. For each sample, 200 ml of seawater was filtered onto a GF/F filter then placed in a 20 ml glass scintillation vial. Ten millilitres, 90% HPLC grade Acetone was added and stored for 24 h in a refrigerator for pigment extraction. Chl-a concentration was measured using a Turner Designs TD-700 fluorometer calibrated with a (Sigma) chl-a standard (determined on a spectrophotometer), following the Welschmeyer (1994) protocol.

N.B. There is a small possibility that later model Trilogy Laboratory Fluorometer could have been used.

References cited

Venables, H.J., Pollard R.T., Popova, E.E., 2007. Physical conditions controlling the development of a regular phytoplankton bloom north of the Crozet Plateau, Southern Ocean Original. Deep-Sea Research II, No. 54, 1949-1965pp.

Welschmeyer, N.A., 1994. Fluoremetric analysis of chlorophyll a in the presence of chlorophyll b and Pheopigments. Limnology and Oceanography No.39 (8), 1985-1992pp.

BODC Data Processing Procedures

A total of 158 samples were provided by the originator as one sample was lost. Data were taken from Table 15.1 from the cruise report and loaded into BODC's database. The sample IDs from this table were kept the same, with the addition of the prefix CHL###. The date and time each sample was taken was not provided by the originator and therefore these were established by taking the time from corresponding latitudes and longitudes from the underway navigation data. The sampling times and locations were then compared with the salinity sampling times and locations. No flags were added by the originator or BODC.

The following table shows how the variable was mapped to appropriate BODC parameter code:

Data Quality Report

None (BODC assessment)

Problem Report

The dates and times of the sampling events have been estimated as these were not provided by the originator. These were extracted from the underway navigation file based on the position. Comparisons between the chlorophyll-a samples and salinity samples which were also taken, revealed two sets of latitude and longitude which were likely to be incorrect. The latitude of sample CHL065 was altered from -45.48 to -45.98 and for sample CHL097, the longitude was altered from 52.97 to 51.97. (BODC assessment)

Project Information

CROZET (Benthic CROZEX)

The CROZET project was a multidisciplinary Benthic study that compliments the CROZet natural iron bloom EXport experiment (CROZEX). It was a Natural Environment Research Council (NERC) funded project (grant number NER/A/S/2003/00573).

The principle objective of CROZET was "To assess how biogeochemical composition and flux of Organic Matter (OM) to the deep-sea floor drive benthic community structure, dynamics and diversity at two sites with contrasting primary production regimes".

Specific hypotheses tested were:

1. That the variability in biogeochemical composition as well as the total flux of OM reaching the abyssal seafloor is dependent on the productivity of the overlying surface waters.
2. That the biogeochemical composition of incoming OM is imprinted on the biochemistry of key detritovores.
3. That key nano-nutrients are critical for the reproduction of some deep-sea species and thus variations in OM flux affect sediment community structure and diversity.
4. That variations in total OM flux also influence benthic rate processes (e.g. faunal activity).

The University of Liverpool Department of Earth Science hosted the project with particiption from another seven research centres/universities.

The project ran from December 2005 to September 2008 with the primary marine data collection during RRS Discovery cruise D300 between 1^st December 2005 and 14^th January 2006. The sediment trap moorings for this project were deployed during the RRS Discovery CROZEX cruises D285 and D286 one year previously.

The cruise primarily sampled stations M5 (an eutrophic region subject to photoplankton blooms) and M6 (to the south of the Crozet Islands and an oligotrophic High Nutrient Low Chlorophyll (HNLC) area) previously occupied during the CROZEX cruises and described in Pollard et al. (2007). The two contrast regions allowed a comparison of the benthic communities that were:

1. At the same depth.
2. In the same physical setting (topographic and hydrographic).
3. Interconnected (with no physical barrier between them).

Where possible the following observations were conducted at each major station:

• Underway navigation, surface, meteorology and bathymetry throughout the cruise
• Underway sampling of:
  • Salinity
  • Nutrients (Nitrogen and Phosphorus)
  • Chlorophyll-a
  • Dissolved Iron
• 150kHz Vessel-Mounted Acoustic Doppler Current Profiller (VMADCP) data throughout the cruise
• Full water column CTD stations for salinity, temperature, chlorophyll and dissolved oxygen. CTD rig included a Lowered Acoustic Doppler Current Profiller (LADCP). CTD water bottles were sampled for:
  • Salinity
  • Particulate Organic Carbon (POC)
  • Particulate Organic Nitrogen (PON)
  • Bacterial biomass and community structure using DNA analyses
  • MPN enumeration and isolation of marine bacteria
  • Particulate iron
  • Chloropyhll-a
• Stand Alone Pumps with analyses of:
  • Organic biogeochemistry
  • Bacterial biomass and community structure using DNA analyses
  • MPN enumeration and isolation of marine bacteria
  • Archael bacteria
  • Particulate Organic Carbon (POC)
  • Particulate Organic Nitrogen (PON)
  • Particulate iron
• Megacoring with analyses of:
  • Total Organic Carbon (TOC)
  • Total Nitrogen (TN)
  • Hydrolysable amino acids
  • Bacterial biomass and community structure using DNA analyses
  • MPN enumeration and isolation of marine bacteria
  • Nematodes
  • Polychaetes
  • Pigments
  • Pigment degradation
  • Meiofauna
  • Foraminifera
  • Macrofauna
  • Pore fluid geochemistry
  • Biomarkers
  • Lipids
  • Solid phase geochemistry
  • Bacteria
• Holothurian sample photography
• WASP sea floor photography and video for study of benthic megafaunal populations
• Fish RESPirometry Lander (FRESP) deployments
• RObust BIOdiversity Lander (ROBIO) deployments (included a current meter)
• Demersal ichthyofauna sampling with analyses of:
  • Species
  • Wet weight
  • Length (total, standard, head and pre-anal)
• Demersal ichthyofauna macrouridae (Rattail) sex, stomach weight, liver (weight, fullness) and sexual maturity
• Bacterial long-term enrichment incubations
• SPRATS Sampling pressure retaining system deployments
• Holothurian pigment analysis (gut and gonad)
• Holothurian - molecular (DNA) analysis
• Holothurian Bacterial samples (gut and cloaca)
• Holothurian lipid analysis

The project has produced significant findings including the discovery of six new species of fish. Further information on the project can be found in the D300 cruise report and the CROZET project web pages.

References

Pollard R., Sanders R., Lucas M. and Statham P., 2007. The Crozet natural iron bloom and export experiment (CROZEX). Deep-Sea Research II, 54, 1905-1914.

Data Activity or Cruise Information

Cruise

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:

SeaDataNet Quality Control Flags

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