Winter Phytoplankton Densities during the 1990-1991 season

Summary

Abstract: 

Using automated overwinter sampling devices, preserved phytoplankton samples were collected from multiple depths in Lake Fryxell, a permanently ice-covered lake in southern Victoria Land, Antarctica. Photosynthetic algae (i.e. algae possessing chloroplasts) are maintained in a stable water column throughout winter darkness. The algal taxa "overwinter" in different ways, in a species specific manner. Typical vegetative cells were the most abundant form for all species found in the water column. Populations of one chlorophyte, Stichococcus sp., and two cryptophyte species increased during winter. We interpret the increase in algal population size as evidence of wintertime heterotrophic growth, and mixotrophic behavior in the context of the entire year. For two chlorophyte species some portion of the population had distinct morphology, e.g. akinetes for Chlamydomonas subcaudata and cells containing a large amount of starch or other storage material for Chlorella sp.. During winter, vegetative cells of the most abundant species of cyanobacteria, Phormidium angustissimum, occurred at the depth of the summertime maximum and at depths below the oxycline, which may represent a "false bottom". Other than this false bottom and the absence of diatoms, settling did not appear to influence the overwinteringalgal community.

Date Range: 

April 15, 1990 to September 6, 1991
Data Citation
Mcknight, D. 2014. McMurdo Dry Valleys LTER: Winter Phytoplankton Densities during the 1990-1991 season. Environmental Data Initiative. DOI: 10.6073/pasta/9ecfbd070217e64b9483356aa7be2b6a. Dataset accessed 15 October 2019.
Dataset(s)

Variables (click to expand): 

LOCATION NAME
  • Label: Location Name
  • Definition: The name of the lake where samples were acquired
  • Type: Nominal
  • Missing values: None specified
DATE_TIME
  • Label: Date
  • Definition: Date on which sample was collected
  • Type: Date/time
  • Date format: mm/dd/yyyy
  • Missing values: None specified
DEPTH (m)
  • Label: Depth (m)
  • Definition: The lake depth were the sample was collected, relative to the ice surface.
  • Type: Physical quantity
  • Unit: meter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: 1
  • Missing values:
    • Null = None given
Phylum
  • Label:
  • Definition: The distinct phylum names corresponding to the measured cell densities
  • Type: Nominal
  • Missing values: None specified
Species
  • Label:
  • Definition: The distinct species name corresponding to the measured cell densities
  • Type: Nominal
  • Missing values: None specified
Species Density (cells/mL)
  • Label:
  • Definition: Species Density (cells/mL)
  • Type: Physical quantity
  • Unit: numberPerMilliliter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: 1
  • Missing values:
    • Null = None given
Phylum Density (cells/mL)
  • Label:
  • Definition: Phylum Density (cells/mL)
  • Type: Physical quantity
  • Unit: numberPerMilliliter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: 1
  • Missing values:
    • Null = None given
Phyto Density (cells/mL)
  • Label: Phytoplankton Density (cells/mL)
  • Definition: Phytoplankton Density (cells/mL)
  • Type: Physical quantity
  • Unit: numberPerMilliliter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: 1
  • Missing values:
    • Null = None given

File: 

phytwntr.csv (57.3 KB)

...or query the dataset by variables and dates of interest:

Short name: 

phytwntr

Dataset ID: 

49
People

Principal Investigator(s): 

Contact: 

Associated Personnel: 

Data Manager