Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation
In the Canadian Arctic, climate change pressure is increasing, while anthropogenic activities and the resulting human impacts on the ecosystem are intensifying. However, fish communities remain poorly documented despite their pivotal role in the ecosystem equilibrium in transferring the energy from...
Main Author: | |
---|---|
Other Authors: | , |
Format: | Thesis |
Language: | French |
Published: |
Université Laval
2019
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11794/38202 |
id |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/38202 |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/38202 2023-05-15T14:30:32+02:00 Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation Recruitment of Arctic cod Boreogadus saida: climate, productivity and predation LeBlanc, Mathieu Fortier, Louis Gauthier, Stéphane Arctique 2019-01-01 https://hdl.handle.net/20.500.11794/38202 fr fre Université Laval http://hdl.handle.net/20.500.11794/38202 CorpusUL envir geo Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2019 fttriple https://doi.org/20.500.11794/38202 2023-01-22T17:37:05Z In the Canadian Arctic, climate change pressure is increasing, while anthropogenic activities and the resulting human impacts on the ecosystem are intensifying. However, fish communities remain poorly documented despite their pivotal role in the ecosystem equilibrium in transferring the energy from zooplankton to top arctic predators. The main objective of this PhD thesis is to document spatial and temporal variations in polar cod Boreogadus saida recruitment in the Canadian Arctic, and the environmental and biological factors influencing these variations. Based on fish abundance and biomass estimated with hydroacoustic data validated by nets and trawls from 2005 to 2017, I investigate: (1) the impacts of an earlier ice breakup and warmer sea surface temperatures (SST) on the survival and recruitment of age-0 polar cod in different regions of the Canadian Arctic; (2) the role of ecosystem productivity in age-0 polar cod recruitment and differences in productivity across three oceanographic provinces of the Canadian Arctic; and (3) the co-distribution of polar cod and its seabird predators across the marginal ice zone in Baffin Bay. Earlier ice breakup in the Canadian Arctic resulted in warmer SST in spring-summer, earlier phytoplankton bloom and higher ecosystem productivity in summer. Early ice breakup also increased juvenile polar cod biomass at the end of summer by allowing the survival of larvae hatched in winter and spring. In light of these results, it seems that both warm temperatures and, mostly, abundant food resource allow age-0 individuals to benefit from an earlier ice breakup, at least for the time being. During the period of the study, ecosystem productivity was similar in the southern Beaufort Sea and the North Water/Lancaster Sound polynya complex, but juvenile polar cod biomass was higher in the Beaufort Sea. Intense avian predation could explain the lower biomass of juvenile cod in the polynya complex, confirming its reputation as a biological hotspot for the transfer of energy to higher ... Thesis Arctic cod Arctic Arctique* Baffin Bay Baffin Bay Baffin Beaufort Sea Boreogadus saida Climate change Lancaster Sound Phytoplankton polar cod Zooplankton Unknown Arctic Baffin Bay Lancaster Sound ENVELOPE(-83.999,-83.999,74.218,74.218) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
envir geo |
spellingShingle |
envir geo LeBlanc, Mathieu Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
topic_facet |
envir geo |
description |
In the Canadian Arctic, climate change pressure is increasing, while anthropogenic activities and the resulting human impacts on the ecosystem are intensifying. However, fish communities remain poorly documented despite their pivotal role in the ecosystem equilibrium in transferring the energy from zooplankton to top arctic predators. The main objective of this PhD thesis is to document spatial and temporal variations in polar cod Boreogadus saida recruitment in the Canadian Arctic, and the environmental and biological factors influencing these variations. Based on fish abundance and biomass estimated with hydroacoustic data validated by nets and trawls from 2005 to 2017, I investigate: (1) the impacts of an earlier ice breakup and warmer sea surface temperatures (SST) on the survival and recruitment of age-0 polar cod in different regions of the Canadian Arctic; (2) the role of ecosystem productivity in age-0 polar cod recruitment and differences in productivity across three oceanographic provinces of the Canadian Arctic; and (3) the co-distribution of polar cod and its seabird predators across the marginal ice zone in Baffin Bay. Earlier ice breakup in the Canadian Arctic resulted in warmer SST in spring-summer, earlier phytoplankton bloom and higher ecosystem productivity in summer. Early ice breakup also increased juvenile polar cod biomass at the end of summer by allowing the survival of larvae hatched in winter and spring. In light of these results, it seems that both warm temperatures and, mostly, abundant food resource allow age-0 individuals to benefit from an earlier ice breakup, at least for the time being. During the period of the study, ecosystem productivity was similar in the southern Beaufort Sea and the North Water/Lancaster Sound polynya complex, but juvenile polar cod biomass was higher in the Beaufort Sea. Intense avian predation could explain the lower biomass of juvenile cod in the polynya complex, confirming its reputation as a biological hotspot for the transfer of energy to higher ... |
author2 |
Fortier, Louis Gauthier, Stéphane |
format |
Thesis |
author |
LeBlanc, Mathieu |
author_facet |
LeBlanc, Mathieu |
author_sort |
LeBlanc, Mathieu |
title |
Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
title_short |
Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
title_full |
Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
title_fullStr |
Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
title_full_unstemmed |
Recrutement de la morue arctique Boreogadus saida : climat, productivité et prédation |
title_sort |
recrutement de la morue arctique boreogadus saida : climat, productivité et prédation |
publisher |
Université Laval |
publishDate |
2019 |
url |
https://hdl.handle.net/20.500.11794/38202 |
op_coverage |
Arctique |
long_lat |
ENVELOPE(-83.999,-83.999,74.218,74.218) |
geographic |
Arctic Baffin Bay Lancaster Sound |
geographic_facet |
Arctic Baffin Bay Lancaster Sound |
genre |
Arctic cod Arctic Arctique* Baffin Bay Baffin Bay Baffin Beaufort Sea Boreogadus saida Climate change Lancaster Sound Phytoplankton polar cod Zooplankton |
genre_facet |
Arctic cod Arctic Arctique* Baffin Bay Baffin Bay Baffin Beaufort Sea Boreogadus saida Climate change Lancaster Sound Phytoplankton polar cod Zooplankton |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/38202 |
op_doi |
https://doi.org/20.500.11794/38202 |
_version_ |
1766304361764356096 |