AUTHOR:
Dr. Evelyn Sherr
Oregon State University
College of Oceanic and Atmospheric Sciences (COAS),104 Oceanography Admin Bldg
Corvallis, OR, 97331-5503
Tel: 541-Phone: 737-4369
e-mail: sherre@coas.oregonstate.edu

PI: Dr. Yvette Spitz, COAS, Oregon State University

NSF GRANT: OPP 0435956

DATE SET OVERVIEW:
This data set includes microplankton abundance and estimated carbon biomass from Niskin bottle casts taken onboard the RV Annika Marie during August - September, 2005 and 2006 in the Chukchi and Beaufort Seas, off the coast of Barrow, Alaska. Each data set presents station, transect or line, water sample depth, chlorophyll a concentration and percent of chlorophyll less than 10 um in size, microzooplankton-sized protists (20-200 um, ciliates and heterotrophic dinoflagellates), cells counted per sample, cells per ml, biomass per ml, heterotrophic dinoflagellates as percent of total microzooplankton protists, and for a subset of samples, separate data on protists greater than 40 um in size.

METHODS:
Water samples were obtained from 5-l Niskin bottles casts from the RV Annika Marie along designated offshore/onshore sample lines. Samples for chlorophyll a were filtered onto Whatman GF/F glass fiber filters. Subsamples were pre-screened through 10 um mesh to separately determine amount of chlorophyll in the less than 10 um fraction. Following 24-h extraction in 90% acetone at -20 degree C, chlorophyll concentrations were determined fluorometrically. Microplankton samples were preserved in 250-ml amber glass bottles with a final concentration of 5% acid Lugol solution. Following settling of 50 to 100 ml subsamples in Utermohl settling chambers for at least 24 hours, the whole chamber slide was inspected by inverted light microscopy at 200x magnification using a Jena Sedival Inverted Research Microscope. Heterotrophic protists from 10-200 um in longest dimension were enumerated, sized, and grouped into taxonomic categories. The biovolume of each enumerated protist cell was determined using algorithms for spherical, conical, and ellipsoidal shapes. Cell biomass (?g C/liter) was estimated from cell biovolumes using the algorithm of Menden-Deuer and Lessard (2000).

Menden-Deuer, S., Lessard, E., 2000. Carbon to volume relationships for dinoflagellates, diatoms, and other protist plankton. Limnology and Oceanography 45, 569-579