Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night
Limnological research on the lakes of the McMurdo Dry Valleys (MCM), Antarctica, is typically carried out during the austral spring-summer (October January) when logistical support is readily available; the current study marks the first sampling effort during the summer-fall transition (January-Apri...
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Montana State University - Bozeman, College of Agriculture
2010
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ftmontanastateu:oai:scholarworks.montana.edu:1/2477 2023-05-15T13:55:57+02:00 Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night Bacterioplankton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night Vick, Trista Juliana Chairperson, Graduate Committee: John C. Priscu. McMurdo Dry Valleys (Antarctica) 2010 application/pdf https://scholarworks.montana.edu/xmlui/handle/1/2477 en eng Montana State University - Bozeman, College of Agriculture https://scholarworks.montana.edu/xmlui/handle/1/2477 Copyright 2010 by Trista Juliana Vick Bacteria Limnology Seasons Thesis 2010 ftmontanastateu 2022-06-06T07:24:42Z Limnological research on the lakes of the McMurdo Dry Valleys (MCM), Antarctica, is typically carried out during the austral spring-summer (October January) when logistical support is readily available; the current study marks the first sampling effort during the summer-fall transition (January-April). Sampling during the darkness of winter is logistically difficult and expensive, and my study is an important step towards understanding the year-round ecology of the dry valley lakes. Bacterial productivity, measured as protein synthesis and DNA replication, and bacterial cell numbers were measured 10-12 times between October 2007 and April 2008 in Lakes Fryxell (FRX) and the east and west lobes of Lake Bonney (ELB and WLB). Lake Fryxell was the most productive (bacterial) lake on average by an order of magnitude (average = 1.24 mg C m -²d -¹; range = 0.00 to 3.29 mg C m -²d -¹), and also contained the greatest bacterial biomass (~10 ⁶ cells ml -¹) by 1 to 3 orders of magnitude. If bacterial production were directly linked to organic carbon supplied by photosynthetic primary production, a decrease in bacterial production would be expected during the sunset; however, no statistically significant change in bacterial production (a=0.05) was observed during the summer-fall transition. A distinct decoupling of bacterial protein production and DNA replication was detected in FRX and ELB of the lakes as the season progressed, and was present in WLB throughout the season, indicating either a shift towards a lower growth-rate in response to decreasing light or nutrient supply, or a mechanism for dealing with the perennially low temperatures, low light, and nutrient poor conditions in the lakes. Overall, it appears that bacterial communities remain active during the darkness of winter, when the lakes enter a period of "net heterotrophy", which cannot be sustained unless the carbon balance of the TV lakes is reset by climatic events. Thesis Antarc* Antarctica McMurdo Dry Valleys polar night Montana State University (MSU): ScholarWorks Austral Bonney ENVELOPE(162.417,162.417,-77.717,-77.717) Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Lake Bonney ENVELOPE(-25.588,-25.588,-80.361,-80.361) Lake Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) McMurdo Dry Valleys Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) |
institution |
Open Polar |
collection |
Montana State University (MSU): ScholarWorks |
op_collection_id |
ftmontanastateu |
language |
English |
topic |
Bacteria Limnology Seasons |
spellingShingle |
Bacteria Limnology Seasons Vick, Trista Juliana Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
topic_facet |
Bacteria Limnology Seasons |
description |
Limnological research on the lakes of the McMurdo Dry Valleys (MCM), Antarctica, is typically carried out during the austral spring-summer (October January) when logistical support is readily available; the current study marks the first sampling effort during the summer-fall transition (January-April). Sampling during the darkness of winter is logistically difficult and expensive, and my study is an important step towards understanding the year-round ecology of the dry valley lakes. Bacterial productivity, measured as protein synthesis and DNA replication, and bacterial cell numbers were measured 10-12 times between October 2007 and April 2008 in Lakes Fryxell (FRX) and the east and west lobes of Lake Bonney (ELB and WLB). Lake Fryxell was the most productive (bacterial) lake on average by an order of magnitude (average = 1.24 mg C m -²d -¹; range = 0.00 to 3.29 mg C m -²d -¹), and also contained the greatest bacterial biomass (~10 ⁶ cells ml -¹) by 1 to 3 orders of magnitude. If bacterial production were directly linked to organic carbon supplied by photosynthetic primary production, a decrease in bacterial production would be expected during the sunset; however, no statistically significant change in bacterial production (a=0.05) was observed during the summer-fall transition. A distinct decoupling of bacterial protein production and DNA replication was detected in FRX and ELB of the lakes as the season progressed, and was present in WLB throughout the season, indicating either a shift towards a lower growth-rate in response to decreasing light or nutrient supply, or a mechanism for dealing with the perennially low temperatures, low light, and nutrient poor conditions in the lakes. Overall, it appears that bacterial communities remain active during the darkness of winter, when the lakes enter a period of "net heterotrophy", which cannot be sustained unless the carbon balance of the TV lakes is reset by climatic events. |
author2 |
Chairperson, Graduate Committee: John C. Priscu. |
format |
Thesis |
author |
Vick, Trista Juliana |
author_facet |
Vick, Trista Juliana |
author_sort |
Vick, Trista Juliana |
title |
Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
title_short |
Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
title_full |
Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
title_fullStr |
Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
title_full_unstemmed |
Bacterioplakton dynamics in stratified lakes of the Taylor Valley, Antarctica during the transition to polar night |
title_sort |
bacterioplakton dynamics in stratified lakes of the taylor valley, antarctica during the transition to polar night |
publisher |
Montana State University - Bozeman, College of Agriculture |
publishDate |
2010 |
url |
https://scholarworks.montana.edu/xmlui/handle/1/2477 |
op_coverage |
McMurdo Dry Valleys (Antarctica) |
long_lat |
ENVELOPE(162.417,162.417,-77.717,-77.717) ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(-25.588,-25.588,-80.361,-80.361) ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(163.000,163.000,-77.617,-77.617) |
geographic |
Austral Bonney Fryxell Lake Bonney Lake Fryxell McMurdo Dry Valleys Taylor Valley |
geographic_facet |
Austral Bonney Fryxell Lake Bonney Lake Fryxell McMurdo Dry Valleys Taylor Valley |
genre |
Antarc* Antarctica McMurdo Dry Valleys polar night |
genre_facet |
Antarc* Antarctica McMurdo Dry Valleys polar night |
op_relation |
https://scholarworks.montana.edu/xmlui/handle/1/2477 |
op_rights |
Copyright 2010 by Trista Juliana Vick |
_version_ |
1766262948374773760 |