The distribution of microplankton in the McMurdo Dry valley lakes, Antarctica: response to ecosystem legacy or present-day climatic controls

Plankton abundance and biomass were investigated in five lakes of the McMurdo Dry Valleys, Antarctica: Lakes Bonney, Fryxell, Joyce, Hoare and Miers. Despite plankton communities being dominated by organisms <100 n in length, there were striking differences between the lakes, including large vari...

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Bibliographic Details
Published in:Polar Biology
Main Authors: Roberts, EC, Priscu, JC, Wolf, C, Lyons, WB, Laybourn-Parry, J
Format: Article in Journal/Newspaper
Language:English
Published: Springer 2004
Subjects:
Biological Sciences
Microbiology
Microbial Ecology
Antarctic
Bonney
Fryxell
Hoare
Lake Fryxell
Lake Joyce
Lake Miers
McMurdo Dry Valleys
Miers
Antarc*
Antarctica
Polar Biology
Online Access:https://doi.org/10.1007/s00300-003-0582-0
http://ecite.utas.edu.au/48997
Description
Summary:Plankton abundance and biomass were investigated in five lakes of the McMurdo Dry Valleys, Antarctica: Lakes Bonney, Fryxell, Joyce, Hoare and Miers. Despite plankton communities being dominated by organisms <100 n in length, there were striking differences between the lakes, including large variations in plankton vertical distribution and differences in total plankton biomass. Bacterial biomass was highest in the anoxic monimolimnia of the meromictic lakes, reaching 191 g C l-1 in Lake Fryxell. Photosynthetic nanoflagellates dominated phytoplankton in the five lakes studied. Highest chlorophyll a concentrations were recorded at the chemocline of Lake Fryxell (21 g chl a l-1). Heterotrophic nanoflagellate concentrations were low, ranging from 2 cells ml-1 in Hoare to 237 cells ml-1 in Bonney. By Antarctic standards, cillates were relatively successful in terms of biomass and diversity in Lakes Fryxell and Hoare. In contrast, Lake Miers possessed extremely low ciliate abundance (<0.04 cells ml-1). On both sampling occasions, copepod nauplii were observed in Lake Joyce. This is the first recording of crustacean zooplankton within the McMurdo Dry Valley Lakes. Because the foodwebs of these lakes are structured by "bottom-up" forces, differences in plankton distributions could be related to the physicochemical characteristics of each lake. The effect of lake evolution (legacy) and present-day climate change on planktonic dynamics is discussed. Springer-Verlag 2003.

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