Pigment Analysis of the Distribution, Succession, and Fate Of Phytoplankton in The Mcmurdo Dry Valley Lakes Of Antarctica
- John C. Priscu
Published Online: 16 MAR 2013
Copyright 1998 by the American Geophysical Union.
Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica
How to Cite
Lizotte, M. P. and Priscu, J. C. (1998) Pigment Analysis of the Distribution, Succession, and Fate Of Phytoplankton in The Mcmurdo Dry Valley Lakes Of Antarctica, in Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica (ed J. C. Priscu), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR072p0229
- Published Online: 16 MAR 2013
- Published Print: 28 JAN 1998
Print ISBN: 9780875908991
Online ISBN: 9781118668313
- Desert ecology—Antarctica—McMurdo Dry Valleys
Phytoplankton populations in lakes of the McMurdo Dry Valleys have been the subject of taxonomic and ecologic study since the early 1960s. Populations in the major lakes studied (Lakes Bonney, Fryxell, Hoare, and Vanda) include various species of chlorophytes, chrysophytes, cryptophytes, and cyanobacteria. Earlier reports were based primarily on microscopic analyses of preserved water samples. We sampled suspended particulate matter from the four lakes listed above for analysis of algal pigments by high-performance liquid chromatographic (HPLC) methods. Fresh waters beneath ice cover in all lakes were dominated by cryptophyte algae, based on alloxanthin-dominated pigment signatures. Deeper, more saline waters in Lake Bonney were dominated by chrysophytes (fucoxanthin-containing algae) and chlorophytes (chlorophyll-b-containing algae). Comparisons with cell counts from Lake Bonney and with published reports of species composition from all the lakes imply that cryptophytes and chrysophytes may have been underestimated by previous microscopic cell counts of preserved water samples. Temporal trends in Lake Bonney showed all three chlorophyll maxima (5 m, 12 m, and 18 m) contained significant quantities of pigments at the onset of light in September and sequential development of deeper phytoplankton populations through the spring growth season. Particles collected early in spring may include significant amounts of detritus that contain pigments. These pigmented particles could include remnants from algal blooms of the previous year's growth season, which may overwinter without significant breakdown because of (1) the slow rate of photo-oxidation under dark, cold conditions, and (2) a paucity of grazing. This explanation is supported by a trend of decreasing chlorophyll breakdown products during the spring, which appear to be photo-oxidized as light intensity increases in Lake Bonney.