AMT12 Microzooplankton abundance and carbon biomass from CTD bottle samples analysed by optical microscopy
Originator's Protocol for Data Acquisition and Analysis
Seawater samples were collected from the CTD Niskin bottles at the pre-dawn cast from up to 4 depths equivalent to 55%, 33%, 14% and 1% surface irradiance. Water samples were fixed with Lugol's solution and formalin directly from the CTD rossette bottles. Slides were prepared for analysis after the cruise. The slides were examined using an inverted microscope at x200 magnification to enumerate microzooplankton taxa (>20 µm) (Gifford and Caron, 2000). Estimations of biomass were made after image analysis to estimate standard geometric shapes (Hillebrand et al. , 1999) and by using carbon to volume conversions: pg C cell -1 = 0.22 x (µm 3 ) 0.939 for ciliates and pg C cell -1 = 0.76 x (µm 3 ) 0.819 for dinoflagellates (Menden-Deuer and Lessard, 2000).
References Cited
Gifford D.J. and Caron D.A., 1999. Sampling, preservation, enumeration and biomass of marine protozooplankton. In: Harris R.P., Wiebe P.H., Lenz J., Skjoldal H.R., Huntley M. (eds) ICES Zooplankton Methodology Manual. Academic Press, London, p 193-221
Hillebrand H., Dürselen C-D., Kirschtel D., Pollingher U. and Zohary T., 1999. Biovolume calculation for pelagic and benthic microalgae. Journal of Phycology, 35, 403-424
Menden-Deuer S. and Lessard E.J., 2000 Carbon to volume relationships for dinoflagellates, diatoms and other protist plankton. Limnology and Oceanography, 45, 569-579
Instrumentation Description
Not applicable for this data set.
BODC Data Processing Procedures
Data were submitted via email in an Excel spreadsheet archived under BODC's accession number PML090045 with data from AMT13 and 14. Sample metadata (Cruise, CTD cast, date, latitude, longitude, and depth) were checked against information held in the database. There were no major discrepancies. However where matching by cast and depth there was a minor discrepancy on cast 51, where sample depth 140m was provided but no bottle was fired at this depth for this cast. Bottles were fired at 122.7m and 160.7m, the sample was linked to bottle fired at 122.7m. A similar discrepancy was found for cast 36, where sample depth 80m was provided but no bottle was fired at this depth for this cast. Bottles were fired at 68.7m and 100m, the sample was linked to bottle fired at 68.7m.
There were columns of abundance and biomass data for 'Total Ciliates (including Tintinnids)', 'Ciliates (excluding Tintinnids)', ' Strombidium spp', ' Strobilidium spp', 'Tintinnids', 'Heterotrophic dinoflagellates >20µm', 'Total dinoflagellates >20µm', 'Others' and 'Total Microzooplankton'. The data titled 'Total Microzooplankton', 'Others' and 'Ciliates (excluding Tintinnids)' were not loaded to the database. 'Total Microzooplankton' = 'Total Ciliates'+'Heterotrophic dinoflagellates' and 'Ciliates (excluding Tintinnids)' = 'Total Ciliates' - 'Tintinnids'. 'Others' relates to particles >20µm that were non-identifiable due to the slide quality. This data can be supplied on request to BODC.
Parameter codes defined in BODC parameter dictionary were assigned to the variables. The abundance data were converted from cells per litre to cells per millilitre and the biomass data were not converted as the units were equivalent (micrograms per litre and milligrams per cubic metre) to be consistent with the units for the relevant parameters in the BODC database.
The data were reformatted and loaded in BODC's samples database under Oracle Relational Database Management System. Data were marked up with BODC parameter codes and loaded into the database. Individual samples were matched by cast and depth.
A parameter mapping table is provided below;
| Originator's Parameter | Units | Description | BODC Parameter Code | Units | Comments |
|---|---|---|---|---|---|
| Total Ciliate (including Tintinnids) abundance | cells l -1 | Abundance of Ciliatea (ITIS: 46212: WoRMS 238375) per unit volume of the water body by optical microscopy | P500M17Z | cells ml -1 | Unit conversion applied x10 -3 |
| Strombidium spp. abundance | cells l -1 | Abundance of Strombidium spp. (ITIS: 46608: WoRMS 101195) per unit volume of the water body by optical microscopy | P985M00Z | cells ml -1 | Unit conversion applied x10 -3 |
| Strobilidium spp. abundance | cells l -1 | Abundance of Strobilidium spp. (ITIS: 46617: WoRMS 101185) per unit volume of the water body by optical microscopy | P968M00Z | cells ml -1 | Unit conversion applied x10 -3 |
| Tintinnid abundance | cells l -1 | Abundance of Tintinnidae (ITIS: 46743: WoRMS 183533) per unit volume of the water body by optical microscopy | P861M00Z | cells ml -1 | Unit conversion applied x10 -3 |
| Heterotrophic dinoflagellates (>20 µm) abundance | cells l -1 | Abundance of Dinophyceae (ITIS: 9874: WoRMS 19542) [Size: >20um Subgroup: heterotrophic] per unit volume of the water body by unspecified staining and epifluorescence microscopy | B4116767 | cells ml -1 | Unit conversion applied x10 -3 |
| Total dinoflagellate (>20 µm) abundance | cells l -1 | Abundance of Dinophyceae (ITIS: 9874: WoRMS 19542) [Size: >20um] per unit volume of the water body by unspecified staining and epifluorescence microscopy | C1A61382 | cells ml -1 | Unit conversion applied x10 -3 |
| Total Ciliate (including Tintinnids) biomass | µg l -1 | Carbon biomass of Ciliatea (ITIS: 46212: WoRMS 238375) per unit volume of the water body by optical microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | S7338A30 | mg m -3 | Units equivalent |
| Strombidium spp. biomass | µg l -1 | Carbon biomass of Strombidium spp. (ITIS: 46608: WoRMS 101195) per unit volume of the water body by optical microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | M225B210 | mg m -3 | Units equivalent |
| Strobilidium spp. biomass | µg l -1 | Carbon biomass of Strobilidium spp. (ITIS: 46617: WoRMS 101185) per unit volume of the water body by optical microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | XAA60639 | mg m -3 | Units equivalent |
| Tintinnid biomass | µg l -1 | Carbon biomass of Tintinnidae (ITIS: 46743: WoRMS 183533) per unit volume of the water body by optical microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | RB6272A6 | mg m -3 | Units equivalent |
| Heterotrophic dinoflagellates (>20 µm) biomass | µg l -1 | Carbon biomass of Dinophyceae (ITIS: 9874: WoRMS 19542) [Size: >20um Subgroup: heterotrophic] per unit volume of the water body by unspecified staining and epifluorescence microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | TA016A49 | mg m -3 | Units equivalent |
| Total dinoflagellate (>20 µm) biomass | µg l -1 | Carbon biomass of Dinophyceae (ITIS: 9874: WoRMS 19542) [Size: >20um] per unit volume of the water body by unspecified staining and epifluorescence microscopy and abundance to carbon conversion using the equations of Menden-Deuer and Lessard (2000) | T9710853 | mg m -3 | Units equivalent |
Data Quality Report
BODC were not advised of specific quality checks carried out by the data originator.
Problem Report
Not relevant to this data set.
