Phytoplankton

Dataset description

CARIACO time series Phytoplankton taxonomy from samples collected during CTD/Niskin casts

 dates:           08 November 1995 (ongoing)
 location:        CARIACO station, Cariaco Basin (10.5 N, 64.67 W) 
 project/cruise:  CARIACO/cruises 001 (ongoing) 
 platform:        R/V Hermano Gines 
 
 Methodology published at CARIACO site

 Change history:
   080301: data contributed in the form of Excel Spreadsheets
           by Laura Laurenzoni, CARIACO Data Manager (IMaRS, USF)
   080708: data reformatted to OCB standards by Terry McKee (WHOI BCO DMO);
   080722: data for cruises 33 and 42 added by Terry McKee (WHOI BCO DMO)
   080722: minor editing of files to make variable identifiers consistent 

Acquisition description

Phytoplankton Taxonomy Methodology

8 July 2008: Prepared for OCB data system by Terry McKee (BCO-DMO)

PI notes

Water samples for phytoplankton taxonomy analysis are usually collected during CTD/Niskin Cast 4 (the first cast of the morning).

Samples are processed according to the Utermoehl (1958) counting chamber method.
Utermoehl, H. (1958). Zur Vervollkommnung der quantitativen Phytoplankton-Methodik. Mitteilungen der Internationalen Vereinigung für Limnologie 9, 1-38.

The original Utermoehl paper was published in German. Hasle translated Utermoehl and it was published in the UNESCO monographs:
Hasle, G.R. (1978a). The inverted-microscope method, pp. 88-96. In: A. Sournia (ed) Phytoplankton Manual. Monographs on oceanographic methodology 6. UNESCO, Paris.
Hasle, G.R. (1978b). Using the inverted microscope, pp.191-196. In: A. Sournia (ed) Phytoplankton Manual. Monographs on oceanographic methodology 6. UNESCO, Paris.

Processing description

BCO-DMO processing notes

The OCB DMO makes very few modifications to the data content as contributed by the CARIACO team.

Data were submitted to BCO-DMO as Microsoft Excel™spreadsheets, one for each cruise. Spreadsheet cells contained counts (organisms per milliliter) for DIATOMS, DINOFLAGELLATES, COCCOLITHOPHORIDS, CYANOBACTERIA, NANOFLAGELLATES, and OTHERS at 8 depths: 1, 7, 15, 25, 35, 55, 75, and 100 meters. Starting with cruise 137, an additional depth was added: Chlorophyll maximum (ChlMax). For profiles where the ChlMax coincided with a pre-set bottle sampling depth (one of the regularly sampled fixed depths) there is no extra data reported for the ChlMax.

Summary information like TOTAL_ABUNDANCE was provided for all cruises, but total counts for individual phytoplankton groups were not consistently provided. If totals appeared on a single sheet, they were included in the conversion to OCB format. Starting with cruise 101, summary information (i.e., total abundance and total number of species for individual groups) were routinely included in the data.

Since the spreadsheets had been prepared over a number of years and by different technicians, there was some variation in content between sheets. The first task before attempting to convert the data was to standardize the nomenclature. Typographical errors were corrected and abbreviations were filled out (eg., COCCOLITHOPHORIDS replaced COCCO.) In addition, Spanish names were translated to English (eg.,DIATOMS replaced DIATOMEAS.) These corrections were applied to the taxon groups, but not individual species names.

Details:
• Data were extracted from Microsoft Excel™ spreadsheets using Mathworks® xls2csv routine.
• For taxon groups, spelling was checked and corrected.
• Spanish spellings were translated to English.
• Underscores were inserted in the spaces between multi-word species names (e.g., Asterionellopsis_glacialis replaced Asterionellopsis glacialis) to allow the database to retrieve them as a single field.
• Zeroes were inserted in the count columns at depths where that species was not observed.
• Taxon group was prepended to the rows that included species within its group.
• A missing data flag (nd) was inserted in the Chlorophyll maximum column for cruises 1 through 136. Starting with cruise 137, the depth of the Chlorophyll maximum was specifically identified.

1. Niskin:

This document is created from the content of the BCO-DMO metadata database.    2009-11-22  09:39:42