Chlorophyll a data, determined shipboard using the Welschmeyer (non-acidification) method (Welschmeyer N.A., 1994. Fluorometric analysis of chlorophyll a in the presence of chlorophyll b and pheopigments. Limnology and Oceanography 39, 1985-1992.). For convenience, these data have been added as a separate column to the existing bottle data for chlorophyll that were determined post-cruise using frozen filters that are posted elsewhere on this site. These measurements were made on a Turner Designs 10AU instrument following 24 hour in-the-dark incubations at 4 degrees C of Whatman glass fiber filters (GFF) in 90% acetone, based upon 250mL bottle samples that were filtered. Calibration of the fluorometer was accomplished using a Turner Designs liquid chlorophyll standard. These data were collected aboard the U.S. Coast Guard Cutter Polar Sea, during the Bering Sea Ecosystem Study-Bering Sea Integrated Ecosystem Research Program (BEST-BSIERP). BEST-BSIERP together are the Bering Sea project.