Dataset: Extracted Chlorophyll and Phaeopigment data collected from R/V Endeavor cruises EN259, EN262, EN264, EN266, and EN267II in the Gulf of Maine and Georges Bank in 1995 as part of the U.S. GLOBEC program (GB project)

Extracted Chlorophyll and Phaeopigment

DMO note: The data reported consists of three replicates per each depth horizon sampled.

PI Responsible: Dian J. Gifford

Samples for water column chlorophyll and phaeopigment were collected and analyzed during the following Vital rates 1995 U.S. GLOBEC Georges Bank process cruises:

• EN259
• EN262
• EN264
• EN266
• EN267B (aka EN267II and EN267 LEG 2)

  Water Collection: Seawater was collected using 10-L teflon-lined Go-flo bottles mounted on the Neil Brown CTD rosette. Water was drained into opaque brown 1-L bottles immediately after collection and refrigerated until processed. Samples were collected onto filters within one hour of water collection. In areas where the water column was well mixed, water was collected from the top, middle and bottom of the water column. When the water column was stratified, water was collected from the top, middles and bottom of the water column as well as around the hydrographic features of interest.

  Sample Processing: Samples were prepared for total, <20 µm, and <5 µm chlorophyll and phaeopigment. Samples for total pigments consisted of bulk seawater. Samples for < 20 µm and < 5 µm pigments were passed gently through clean Nitex meshes of appropriate porosity and the filtrate retained for analysis. Three replicate 50-ml samples of each size fraction were collected onto 25 mm GF/F filters, placed into 5 ml of 90% acetone in a capped test tube, and extracted in the freezer for 24 hours prior to analysis.

  Sample Analysis: The filters were removed from defrosted test tubes with a clean stainless steel spatula, the tube wiped clean with a Kimwipe, and samples read on a Turner Designs Model 10 fluorometer before and after acidification with 10% HCl (Parsons et al., 1984).

  Caveat: In general, pigment concentrations in the <5 µm samples were approximately equal to the <20 µm samples (i.e., there was very little chlorophyll in the 5-20 µm size range: most chlorophyll < 20 µm was also < 5 µm). Because of the difficulty of passing seawater quantitatively through the 5 µm mesh, the <5 µm data are more variable than the Total and < 20 µm data. To avoid confusion, the < 5 µm data are not included in the data files. The data are available, and scientific investigators who need it should contact the PI directly.

  Data Use: The data are available for use by any scientific investigator who wishes to use them. The PI must be consulted prior to publication.

  
  Data Submitted by: 
  
  Dian J. Gifford
  Graduate School of Oceanography
  University of Rhode Island
  Narragansett, RI 02882-1197
  
  voice:   401-874-6690
  fax:     401-874-6240
  e-mail:  gifford@gsosun1.gso.uri.edu
  
  updated: Aug 05. 2005, gfh