Diversity and distribution of heterotrophic flagellates in the Arctic Ocean
In marine environments, single-celled protists form the initial links of the food web. Heterotrophic flagellates (HF) play a key role by grazing on bacteria and phytoplankton, being grazed upon in their turn by microzooplankton such as dinoflagellates and ciliates. The extreme environmental changes...
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fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/24836 2023-05-15T14:50:04+02:00 Diversity and distribution of heterotrophic flagellates in the Arctic Ocean Thaler, Mary Lovejoy, Connie Arctique, Océan 2014-01-01 https://hdl.handle.net/20.500.11794/24836 en eng Université Laval http://hdl.handle.net/20.500.11794/24836 CorpusUL geo envir Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2014 fttriple https://doi.org/20.500.11794/24836 2023-01-22T17:01:02Z In marine environments, single-celled protists form the initial links of the food web. Heterotrophic flagellates (HF) play a key role by grazing on bacteria and phytoplankton, being grazed upon in their turn by microzooplankton such as dinoflagellates and ciliates. The extreme environmental changes currently taking place in the Arctic Ocean are expected to transform protist communities. The subject of this thesis is the taxonomic composition of marine HF communities in the Arctic Ocean, and their response to environmental factors. The approach was to use fluorescent oligonucleotide probes to assess the abundance of two important HF taxa, the genus Cryothecomonas and the clade MAST-1 of the marine stramenopiles, via microscope counts. A complementary approach was to describe distribution of all HF taxa, including Cryomonadida, marine stramenopiles, Picozoa, Telonemia and choanoflagellates, by means of high-throughput sequencing. Results from these two approaches allowed us to capture broad environmental trends over a large geographic scale in the Arctic. A picture emerged of taxonomic composition largely structured by the influence of sea ice and other environmental factors. Cryothecomonas cells are inferred to live principally in the sea ice, and in the water column are more numerous close to the ice edge, whereas three sub-clades of MAST-1 are all found principally in the water column but are distributed differently relative to ice cover and marginal ice zones. The composition of the total HF community also varied by region, with a greater importance of Telonemia and choanoflagellates in the Canada Basin. For several taxa it was possible to identify one or two dominant phylotypes in a given region. The relative importance of these taxa is expected to change as sea ice retreat continues in the High Arctic, leading to important changes in trophic webs and biogeochemical cycles. Dans les environnements marins arctiques, les protistes unicellulaires constituent les premiers maillons du réseau trophique. Les ... Thesis Arctic Arctic Ocean Arctique* canada basin Phytoplankton Sea ice Unknown Arctic Arctic Ocean Canada |
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op_collection_id |
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language |
English |
topic |
geo envir |
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geo envir Thaler, Mary Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
topic_facet |
geo envir |
description |
In marine environments, single-celled protists form the initial links of the food web. Heterotrophic flagellates (HF) play a key role by grazing on bacteria and phytoplankton, being grazed upon in their turn by microzooplankton such as dinoflagellates and ciliates. The extreme environmental changes currently taking place in the Arctic Ocean are expected to transform protist communities. The subject of this thesis is the taxonomic composition of marine HF communities in the Arctic Ocean, and their response to environmental factors. The approach was to use fluorescent oligonucleotide probes to assess the abundance of two important HF taxa, the genus Cryothecomonas and the clade MAST-1 of the marine stramenopiles, via microscope counts. A complementary approach was to describe distribution of all HF taxa, including Cryomonadida, marine stramenopiles, Picozoa, Telonemia and choanoflagellates, by means of high-throughput sequencing. Results from these two approaches allowed us to capture broad environmental trends over a large geographic scale in the Arctic. A picture emerged of taxonomic composition largely structured by the influence of sea ice and other environmental factors. Cryothecomonas cells are inferred to live principally in the sea ice, and in the water column are more numerous close to the ice edge, whereas three sub-clades of MAST-1 are all found principally in the water column but are distributed differently relative to ice cover and marginal ice zones. The composition of the total HF community also varied by region, with a greater importance of Telonemia and choanoflagellates in the Canada Basin. For several taxa it was possible to identify one or two dominant phylotypes in a given region. The relative importance of these taxa is expected to change as sea ice retreat continues in the High Arctic, leading to important changes in trophic webs and biogeochemical cycles. Dans les environnements marins arctiques, les protistes unicellulaires constituent les premiers maillons du réseau trophique. Les ... |
author2 |
Lovejoy, Connie |
format |
Thesis |
author |
Thaler, Mary |
author_facet |
Thaler, Mary |
author_sort |
Thaler, Mary |
title |
Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
title_short |
Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
title_full |
Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
title_fullStr |
Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
title_full_unstemmed |
Diversity and distribution of heterotrophic flagellates in the Arctic Ocean |
title_sort |
diversity and distribution of heterotrophic flagellates in the arctic ocean |
publisher |
Université Laval |
publishDate |
2014 |
url |
https://hdl.handle.net/20.500.11794/24836 |
op_coverage |
Arctique, Océan |
geographic |
Arctic Arctic Ocean Canada |
geographic_facet |
Arctic Arctic Ocean Canada |
genre |
Arctic Arctic Ocean Arctique* canada basin Phytoplankton Sea ice |
genre_facet |
Arctic Arctic Ocean Arctique* canada basin Phytoplankton Sea ice |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/24836 |
op_doi |
https://doi.org/20.500.11794/24836 |
_version_ |
1766321145430147072 |