Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay
In Arctic marine environments, the renewal of surface nutrient stocks through physical and biogeochemical processes during winter is critical to support primary production later in the season when solar irradiance is sufficient. Landfast sea-ice and river discharge in the riverine coastal domain inf...
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ftunivmanitoba:oai:mspace.lib.umanitoba.ca:1993/36315 2023-06-18T03:39:23+02:00 Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay Guzzi, Alessia Kuzyk, Zou Zou (Environment and Geography) Ehn, Jens (Environment and Geography) Michel, Christine (Environment and Geography) Macdonald, Robie (Environment and Geography) 2022-02-10T05:14:07Z application/pdf http://hdl.handle.net/1993/36315 eng eng http://hdl.handle.net/1993/36315 open access Hudson Bay James Bay Freshwater Nutrients Nitrate Phosphate Riverine Coastal Domain River discharge La Grande River master thesis 2022 ftunivmanitoba 2023-06-04T17:41:20Z In Arctic marine environments, the renewal of surface nutrient stocks through physical and biogeochemical processes during winter is critical to support primary production later in the season when solar irradiance is sufficient. Landfast sea-ice and river discharge in the riverine coastal domain influence not only the structure of the coastal water column, but also impact the movement and distribution of nutrients within the system. Over the last several decades, both climate change and anthropogenic activities have caused shifts in both sea-ice and riverine cycles. Winter freshwater tracer and nutrient data from Canadian Arctic coastal areas, such as in Hudson Bay are extremely scarce. In this thesis I begin to fill this gap, focusing on three coastal regions: northeast James Bay (NEJB), northwest Hudson Bay (NWHB), and southeast Hudson Bay (SEHB). The objective is to evaluate the relationships between freshwater sources and nutrient distributions, during ice-covered and ice-free seasons, across the selected coastal domains. I present new nutrient (nitrate, phosphate, and silicate) and freshwater tracer (oxygen isotope ratio, salinity) data for water samples collected during ice-covered conditions, and additionally, data from open-water conditions in NEJB. Samples were collected with the help of numerous community members and guides between 2016-2019. Each region was distinct in terms of freshwater composition and influence, with NEJB strongly influenced by La Grande River, as its large under-ice plume (because of regulation) drove surface nutrient concentrations in winter (high nitrate, low phosphate). The sea-ice cycle (withdrawal of freshwater and release of brine during formation) was the dominant influence on NWHB coastal waters. Here there are large concentration ranges of nutrients within a small salinity range, possibly due to an alternate source water, or recirculation of HB outflow. SEHB coastal waters are largely influenced by riverine input from local rivers, and from the upstream James Bay outlet. ... Master Thesis Arctic Climate change Hudson Bay La Grande River Sea ice James Bay MSpace at the University of Manitoba Arctic Hudson Bay Hudson |
institution |
Open Polar |
collection |
MSpace at the University of Manitoba |
op_collection_id |
ftunivmanitoba |
language |
English |
topic |
Hudson Bay James Bay Freshwater Nutrients Nitrate Phosphate Riverine Coastal Domain River discharge La Grande River |
spellingShingle |
Hudson Bay James Bay Freshwater Nutrients Nitrate Phosphate Riverine Coastal Domain River discharge La Grande River Guzzi, Alessia Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
topic_facet |
Hudson Bay James Bay Freshwater Nutrients Nitrate Phosphate Riverine Coastal Domain River discharge La Grande River |
description |
In Arctic marine environments, the renewal of surface nutrient stocks through physical and biogeochemical processes during winter is critical to support primary production later in the season when solar irradiance is sufficient. Landfast sea-ice and river discharge in the riverine coastal domain influence not only the structure of the coastal water column, but also impact the movement and distribution of nutrients within the system. Over the last several decades, both climate change and anthropogenic activities have caused shifts in both sea-ice and riverine cycles. Winter freshwater tracer and nutrient data from Canadian Arctic coastal areas, such as in Hudson Bay are extremely scarce. In this thesis I begin to fill this gap, focusing on three coastal regions: northeast James Bay (NEJB), northwest Hudson Bay (NWHB), and southeast Hudson Bay (SEHB). The objective is to evaluate the relationships between freshwater sources and nutrient distributions, during ice-covered and ice-free seasons, across the selected coastal domains. I present new nutrient (nitrate, phosphate, and silicate) and freshwater tracer (oxygen isotope ratio, salinity) data for water samples collected during ice-covered conditions, and additionally, data from open-water conditions in NEJB. Samples were collected with the help of numerous community members and guides between 2016-2019. Each region was distinct in terms of freshwater composition and influence, with NEJB strongly influenced by La Grande River, as its large under-ice plume (because of regulation) drove surface nutrient concentrations in winter (high nitrate, low phosphate). The sea-ice cycle (withdrawal of freshwater and release of brine during formation) was the dominant influence on NWHB coastal waters. Here there are large concentration ranges of nutrients within a small salinity range, possibly due to an alternate source water, or recirculation of HB outflow. SEHB coastal waters are largely influenced by riverine input from local rivers, and from the upstream James Bay outlet. ... |
author2 |
Kuzyk, Zou Zou (Environment and Geography) Ehn, Jens (Environment and Geography) Michel, Christine (Environment and Geography) Macdonald, Robie (Environment and Geography) |
format |
Master Thesis |
author |
Guzzi, Alessia |
author_facet |
Guzzi, Alessia |
author_sort |
Guzzi, Alessia |
title |
Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
title_short |
Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
title_full |
Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
title_fullStr |
Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
title_full_unstemmed |
Freshwater and nutrient distributions in contrasting coastal domains of Hudson Bay and James Bay |
title_sort |
freshwater and nutrient distributions in contrasting coastal domains of hudson bay and james bay |
publishDate |
2022 |
url |
http://hdl.handle.net/1993/36315 |
geographic |
Arctic Hudson Bay Hudson |
geographic_facet |
Arctic Hudson Bay Hudson |
genre |
Arctic Climate change Hudson Bay La Grande River Sea ice James Bay |
genre_facet |
Arctic Climate change Hudson Bay La Grande River Sea ice James Bay |
op_relation |
http://hdl.handle.net/1993/36315 |
op_rights |
open access |
_version_ |
1769004138148921344 |