Limnologie du Nord de l'Île d'Ellesmere
The lakes and fjords of northern Ellesmere Island, Nunavut, harbor unique ice-dependant ecosystems. Some of these “cryo-ecosystems” are permanently stratified, with a freshwater layer overlying sea water. This extreme stratification is due in part to the limitation of wind-derived mixing because of...
Main Author: | |
---|---|
Other Authors: | |
Format: | Thesis |
Language: | French |
Published: |
Université Laval
2005
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11794/19428 |
id |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/19428 |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/19428 2023-05-15T15:16:11+02:00 Limnologie du Nord de l'Île d'Ellesmere Limnology of the Northern Isle of Ellesmere Van Hove, Patrick Vincent, Warwick F. Nunavut 2005-01-01 https://hdl.handle.net/20.500.11794/19428 fr fre Université Laval http://hdl.handle.net/20.500.11794/19428 CorpusUL geo envir Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2005 fttriple https://doi.org/20.500.11794/19428 2023-01-22T17:04:05Z The lakes and fjords of northern Ellesmere Island, Nunavut, harbor unique ice-dependant ecosystems. Some of these “cryo-ecosystems” are permanently stratified, with a freshwater layer overlying sea water. This extreme stratification is due in part to the limitation of wind-derived mixing because of the presence of a perennial ice-cover. The main objective of the work presented here was to evaluate the limnological and biological diversity of coastal lakes of northern Ellesmere Island in order to better understand their response to environmental change at two timescales: their long term variations over the Holocene and their recent responses to climate over the last few decades. The environments were shown to form a limnological chronosequence that reflected landscape evolution at the Holocene timescale, from stratified fjords to freshwater lakes, via phases in which the water bodies were stratified, meromictic lakes with different degrees of wind-induced mixing depending on the duration of ice cover, from perennial to seasonally open water conditions under warmer climates. Each of these phases is represented today in northern Nunavut. The sensitivity of these stratified ecosystems to environmental change at shorter timescales was then explored, by observing the limnological impacts of current climate change in the Ellesmere Island region. As a first step towards addressing the question of biodiversity and microbial community structure in these ecosystems, a molecular ecology analysis of the lake and fjord biota was made, and underscored the dominance of picocyanobacteria in their surface waters, in contrast with the low abundance of these microbes in the Arctic Ocean, from which those aquatic environments originate. The DNA analysis of the picocyanobacteria implied broad tolerances among these organisms, with the same genetic groups found in a great variety of environments, both on a local and a planetary scale. Finally, a study was undertaken of the zooplankton communities in a lake and fjord of northern ... Thesis Arctic Arctic Ocean Climate change Ellesmere Island Nunavut Zooplankton Unknown Arctic Arctic Ocean Ellesmere Island Nunavut |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
geo envir |
spellingShingle |
geo envir Van Hove, Patrick Limnologie du Nord de l'Île d'Ellesmere |
topic_facet |
geo envir |
description |
The lakes and fjords of northern Ellesmere Island, Nunavut, harbor unique ice-dependant ecosystems. Some of these “cryo-ecosystems” are permanently stratified, with a freshwater layer overlying sea water. This extreme stratification is due in part to the limitation of wind-derived mixing because of the presence of a perennial ice-cover. The main objective of the work presented here was to evaluate the limnological and biological diversity of coastal lakes of northern Ellesmere Island in order to better understand their response to environmental change at two timescales: their long term variations over the Holocene and their recent responses to climate over the last few decades. The environments were shown to form a limnological chronosequence that reflected landscape evolution at the Holocene timescale, from stratified fjords to freshwater lakes, via phases in which the water bodies were stratified, meromictic lakes with different degrees of wind-induced mixing depending on the duration of ice cover, from perennial to seasonally open water conditions under warmer climates. Each of these phases is represented today in northern Nunavut. The sensitivity of these stratified ecosystems to environmental change at shorter timescales was then explored, by observing the limnological impacts of current climate change in the Ellesmere Island region. As a first step towards addressing the question of biodiversity and microbial community structure in these ecosystems, a molecular ecology analysis of the lake and fjord biota was made, and underscored the dominance of picocyanobacteria in their surface waters, in contrast with the low abundance of these microbes in the Arctic Ocean, from which those aquatic environments originate. The DNA analysis of the picocyanobacteria implied broad tolerances among these organisms, with the same genetic groups found in a great variety of environments, both on a local and a planetary scale. Finally, a study was undertaken of the zooplankton communities in a lake and fjord of northern ... |
author2 |
Vincent, Warwick F. |
format |
Thesis |
author |
Van Hove, Patrick |
author_facet |
Van Hove, Patrick |
author_sort |
Van Hove, Patrick |
title |
Limnologie du Nord de l'Île d'Ellesmere |
title_short |
Limnologie du Nord de l'Île d'Ellesmere |
title_full |
Limnologie du Nord de l'Île d'Ellesmere |
title_fullStr |
Limnologie du Nord de l'Île d'Ellesmere |
title_full_unstemmed |
Limnologie du Nord de l'Île d'Ellesmere |
title_sort |
limnologie du nord de l'île d'ellesmere |
publisher |
Université Laval |
publishDate |
2005 |
url |
https://hdl.handle.net/20.500.11794/19428 |
op_coverage |
Nunavut |
geographic |
Arctic Arctic Ocean Ellesmere Island Nunavut |
geographic_facet |
Arctic Arctic Ocean Ellesmere Island Nunavut |
genre |
Arctic Arctic Ocean Climate change Ellesmere Island Nunavut Zooplankton |
genre_facet |
Arctic Arctic Ocean Climate change Ellesmere Island Nunavut Zooplankton |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/19428 |
op_doi |
https://doi.org/20.500.11794/19428 |
_version_ |
1766346480161914880 |