Bio-optical characteristics of diatom and prymnesiophyte populations in the Labrador Sea

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 201:91-106 (2000) - doi:10.3354/meps201091 Bio-optical characteristics of diatom and prymnesiophyte populations in the Labrador Sea V. Stuart1,2,*, S. Sathyendranath1,2, E. J. H. Head1, T. Platt1, B. Irwin1, H. Maass1 1Bedford Institute of Oceanography, PO Box 1006, Dartmouth, Nova Scotia B2Y 4A2, Canada 2Oceanography Department, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada *E-mail: [e-mail] ABSTRACT: During the spring of 1996, phytoplankton samples were collected along a transect from South Wolf Island (Labrador) to Cape Desolation (Greenland). Dense blooms of diatoms were found over the shelf near the coast of Labrador, whereas high concentrations of the colony-forming prymnesiophyte Phaeocystis pouchetii were found close to Greenland. Phytoplankton samples were separated into 2 major groups (diatoms or prymnesiophytes) on the basis of chlorophyll (chl) chl c3/chl a ratios (determined by HPLC analysis), and the effects of species composition on the absorption and photosynthetic characteristics of these 2 high-latitude phytoplankton populations were studied. At all pigment concentrations and all wavelengths examined (apart from 623 nm), the diatom population had a much lower absorption coefficient than the prymnesiophyte population; this was attributed to an increased pigment-packaging effect in the larger diatom cells. Varying proportions of photoprotective pigments also influenced the absorption characteristics of these populations. The low specific-absorption coefficient of the diatom population resulted in a higher maximum photosynthetic quantum yield relative to that of the prymnesiophyte population. The initial slope of the photosynthesis-irradiance (P E) curve (αB) also appeared to be taxon-specific, with higher αB values being recorded for the smaller prymnesiophytes than for the larger diatom cells. The implications of species-dependent variations in phytoplankton absorption coefficients for the retrieval of remotely-sensed chl a are discussed. KEY WORDS: Phytoplankton absorption · Bio-optical characteristics · Photosynthesis-irradiance curve · High latitudes · HPLC pigments Full article in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 201. Online publication date: August 09, 2000 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2000 Inter-Research.