Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes.
Thawing permafrost – in the form of shoreline retrogressive thaw slump events – influence adjacent arctic tundra lake systems near Inuvik, NT. Slump-affected lakes demonstrated lower organic matter and key nutrients such as phosphorus (P), as well as greater water clarity. Key terrestrial permafrost...
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Université d'Ottawa / University of Ottawa
2017
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ftunivottawa:oai:ruor.uottawa.ca:10393/35679 2023-05-15T15:01:51+02:00 Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. Houben, Adam James Blais, Jules 2017 application/pdf http://hdl.handle.net/10393/35679 https://doi.org/10.20381/ruor-636 en eng Université d'Ottawa / University of Ottawa http://hdl.handle.net/10393/35679 http://dx.doi.org/10.20381/ruor-636 Climate Change Permafrost Thaw Slump Freshwater Nutrients Primary production Mercury Mining Arsenic Thesis 2017 ftunivottawa https://doi.org/10.20381/ruor-636 2021-01-04T18:26:44Z Thawing permafrost – in the form of shoreline retrogressive thaw slump events – influence adjacent arctic tundra lake systems near Inuvik, NT. Slump-affected lakes demonstrated lower organic matter and key nutrients such as phosphorus (P), as well as greater water clarity. Key terrestrial permafrost soil indicators such as U, Sr, and Li, were identified to be elevated in slump-affected lakes, while other more biologically important metals (e.g. Fe, Mn) were significantly lower in affected lakes. These physical-chemical changes led to increasing P-limitation for both phytoplankton and periphyton, resulting in lower phytoplankton biomass (Chl-a). Using P as covariate in ANCOVA analysis, slump-affected lakes were also lower in phytoplankton biomass (Chl-a) relative to other study landscapes across the Canadian low-Arctic. Slump-affected lakes also exhibited lower organic matter leading to lower overall Hg concentrations within slump-affected lakes. However, this same reduction in dissolved organic carbon (DOC) has also led to an increase in bioavailable Hg, and increased bioaccumulation of Hg in both periphyton as well as macroinvertebrate species in our most disturbed lakes with DOC concentrations less than 6 and 9 mg DOC/L, respectively. A negative correlation between Hg bioaccumulation and DOC above these concentrations was also observed, and is the typical condition within reference lakes. The legacy impacts of mining were also observed in lakes within 25 km of the Giant Mine roaster stack in the Yellowknife region. Increases in both arsenic (As) and methyl mercury were measured in lakes nearer to the mine, with As concentrations well above water quality guidelines in lakes within 17 km of the roaster stack. This research highlights the necessity of baseline environmental monitoring prior to resource development, as well as the potential for compounded influences of such development within sensitive permafrost regions exposed to thawing. Thesis Arctic Climate change Inuvik Northwest Territories permafrost Phytoplankton Tundra Yellowknife uO Research (University of Ottawa - uOttawa) Arctic Inuvik ENVELOPE(-133.610,-133.610,68.341,68.341) Northwest Territories Yellowknife |
institution |
Open Polar |
collection |
uO Research (University of Ottawa - uOttawa) |
op_collection_id |
ftunivottawa |
language |
English |
topic |
Climate Change Permafrost Thaw Slump Freshwater Nutrients Primary production Mercury Mining Arsenic |
spellingShingle |
Climate Change Permafrost Thaw Slump Freshwater Nutrients Primary production Mercury Mining Arsenic Houben, Adam James Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
topic_facet |
Climate Change Permafrost Thaw Slump Freshwater Nutrients Primary production Mercury Mining Arsenic |
description |
Thawing permafrost – in the form of shoreline retrogressive thaw slump events – influence adjacent arctic tundra lake systems near Inuvik, NT. Slump-affected lakes demonstrated lower organic matter and key nutrients such as phosphorus (P), as well as greater water clarity. Key terrestrial permafrost soil indicators such as U, Sr, and Li, were identified to be elevated in slump-affected lakes, while other more biologically important metals (e.g. Fe, Mn) were significantly lower in affected lakes. These physical-chemical changes led to increasing P-limitation for both phytoplankton and periphyton, resulting in lower phytoplankton biomass (Chl-a). Using P as covariate in ANCOVA analysis, slump-affected lakes were also lower in phytoplankton biomass (Chl-a) relative to other study landscapes across the Canadian low-Arctic. Slump-affected lakes also exhibited lower organic matter leading to lower overall Hg concentrations within slump-affected lakes. However, this same reduction in dissolved organic carbon (DOC) has also led to an increase in bioavailable Hg, and increased bioaccumulation of Hg in both periphyton as well as macroinvertebrate species in our most disturbed lakes with DOC concentrations less than 6 and 9 mg DOC/L, respectively. A negative correlation between Hg bioaccumulation and DOC above these concentrations was also observed, and is the typical condition within reference lakes. The legacy impacts of mining were also observed in lakes within 25 km of the Giant Mine roaster stack in the Yellowknife region. Increases in both arsenic (As) and methyl mercury were measured in lakes nearer to the mine, with As concentrations well above water quality guidelines in lakes within 17 km of the roaster stack. This research highlights the necessity of baseline environmental monitoring prior to resource development, as well as the potential for compounded influences of such development within sensitive permafrost regions exposed to thawing. |
author2 |
Blais, Jules |
format |
Thesis |
author |
Houben, Adam James |
author_facet |
Houben, Adam James |
author_sort |
Houben, Adam James |
title |
Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
title_short |
Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
title_full |
Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
title_fullStr |
Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
title_full_unstemmed |
Effect of Shoreline Subsidence and Anthropogenic Activity on Northwest Territories’ Lakes. |
title_sort |
effect of shoreline subsidence and anthropogenic activity on northwest territories’ lakes. |
publisher |
Université d'Ottawa / University of Ottawa |
publishDate |
2017 |
url |
http://hdl.handle.net/10393/35679 https://doi.org/10.20381/ruor-636 |
long_lat |
ENVELOPE(-133.610,-133.610,68.341,68.341) |
geographic |
Arctic Inuvik Northwest Territories Yellowknife |
geographic_facet |
Arctic Inuvik Northwest Territories Yellowknife |
genre |
Arctic Climate change Inuvik Northwest Territories permafrost Phytoplankton Tundra Yellowknife |
genre_facet |
Arctic Climate change Inuvik Northwest Territories permafrost Phytoplankton Tundra Yellowknife |
op_relation |
http://hdl.handle.net/10393/35679 http://dx.doi.org/10.20381/ruor-636 |
op_doi |
https://doi.org/10.20381/ruor-636 |
_version_ |
1766333865481207808 |