The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge
Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigm...
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ftunivmanitoba:oai:mspace.lib.umanitoba.ca:1993/227 2023-06-18T03:39:40+02:00 The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge Ryan, Michael J. Stern, Gary A. (Soil Science, Environmental Studies) Goldsborough, Gordon (Botany) Kidd, Karen (Zoology) Hickie, Brendan (Trent University) Amiro, Brian (Soil Science) 2007-03-29T16:09:36Z 2422314 bytes application/pdf http://hdl.handle.net/1993/227 eng eng Ryan, M.J., G.A. Stern, M.V. Croft, K. Kidd, M. Diamond and P. Roach (2005). Temporal Trends of Organochlorine Contaminants in Burbot and Lake trout from Three Selected Yukon Lakes. Sci. Tot. Environ. 351-352: 501-522 http://hdl.handle.net/1993/227 open access ecotoxicology organochlorines fish food web temporal trend climate Yukon Territory sub-Arctic plankton sediment doctoral thesis 2007 ftunivmanitoba 2023-06-04T17:37:22Z Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigma-CHB), sigma-PCB and chlorinated benzenes (sigma-CBz) in sentinel fish (species of consistent annual observation and collection) from two Yukon lakes (Kusawa, Quiet), and from the aquatic food web of a focus lake (Lake Laberge) across several temporal points between 1993 and 2003. OC analysis and phytoplankton counts from dated sediment cores as well as climate data were also collected. Population, morphological (length, weight, age), biochemical (lipid content, delta-13C, delta-15N) and OC contaminant data for fish and invertebrates (zooplankton, snails, clams) were reviewed to elucidate the primary causes for these OC declines. Although some spatial differences in contaminant levels exist between the Yukon lakes, OC concentrations were declining for lake trout in all three lakes, with declines also noted for burbot from Lake Laberge. Several other fish species as well as zooplankton from Lake Laberge exhibited decreases in contaminant levels except northern pike, which registered consistently higher levels from 1993 to 2001. There was no evidence to support the hypotheses of changes in fish trophic levels or food sources with the exception of burbot, which marginally decreased, and northern pike, which climbed a half trophic level. Through OC flux analysis in dated sediments, the hypothesis that declines in abiotic deposition affected the contaminant levels in the food web was also negated. The closure of the Lake Laberge commercial fishery resulted in faster fish growth and larger fish populations, which are contributing to biomass dilution of OC concentrations, higher OC biomagnification factors for some species and likely changes in predator-prey interactions as resource competition increases. The large ratio of ... Doctoral or Postdoctoral Thesis Arctic Burbot Lake Laberge Northern pike Phytoplankton Zooplankton Yukon MSpace at the University of Manitoba Arctic Lake Laberge ENVELOPE(-135.193,-135.193,61.183,61.183) Yukon |
institution |
Open Polar |
collection |
MSpace at the University of Manitoba |
op_collection_id |
ftunivmanitoba |
language |
English |
topic |
ecotoxicology organochlorines fish food web temporal trend climate Yukon Territory sub-Arctic plankton sediment |
spellingShingle |
ecotoxicology organochlorines fish food web temporal trend climate Yukon Territory sub-Arctic plankton sediment Ryan, Michael J. The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
topic_facet |
ecotoxicology organochlorines fish food web temporal trend climate Yukon Territory sub-Arctic plankton sediment |
description |
Periodic monitoring of contaminant levels in fish from the Yukon Territory indicated that organochlorine (OC) contaminants had rapidly declined since the early 1990s. This study examined OC concentrations, including chlordane (sigma-CHL), sigma-DDT, hexachlorocyclohexane (sigma-HCH), toxaphene (sigma-CHB), sigma-PCB and chlorinated benzenes (sigma-CBz) in sentinel fish (species of consistent annual observation and collection) from two Yukon lakes (Kusawa, Quiet), and from the aquatic food web of a focus lake (Lake Laberge) across several temporal points between 1993 and 2003. OC analysis and phytoplankton counts from dated sediment cores as well as climate data were also collected. Population, morphological (length, weight, age), biochemical (lipid content, delta-13C, delta-15N) and OC contaminant data for fish and invertebrates (zooplankton, snails, clams) were reviewed to elucidate the primary causes for these OC declines. Although some spatial differences in contaminant levels exist between the Yukon lakes, OC concentrations were declining for lake trout in all three lakes, with declines also noted for burbot from Lake Laberge. Several other fish species as well as zooplankton from Lake Laberge exhibited decreases in contaminant levels except northern pike, which registered consistently higher levels from 1993 to 2001. There was no evidence to support the hypotheses of changes in fish trophic levels or food sources with the exception of burbot, which marginally decreased, and northern pike, which climbed a half trophic level. Through OC flux analysis in dated sediments, the hypothesis that declines in abiotic deposition affected the contaminant levels in the food web was also negated. The closure of the Lake Laberge commercial fishery resulted in faster fish growth and larger fish populations, which are contributing to biomass dilution of OC concentrations, higher OC biomagnification factors for some species and likely changes in predator-prey interactions as resource competition increases. The large ratio of ... |
author2 |
Stern, Gary A. (Soil Science, Environmental Studies) Goldsborough, Gordon (Botany) Kidd, Karen (Zoology) Hickie, Brendan (Trent University) Amiro, Brian (Soil Science) |
format |
Doctoral or Postdoctoral Thesis |
author |
Ryan, Michael J. |
author_facet |
Ryan, Michael J. |
author_sort |
Ryan, Michael J. |
title |
The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
title_short |
The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
title_full |
The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
title_fullStr |
The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
title_full_unstemmed |
The biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three Yukon lakes: focus on Lake Laberge |
title_sort |
biotic and abiotic interactions influencing organochlorine contaminants in temporal trends (1992-2003) of three yukon lakes: focus on lake laberge |
publishDate |
2007 |
url |
http://hdl.handle.net/1993/227 |
long_lat |
ENVELOPE(-135.193,-135.193,61.183,61.183) |
geographic |
Arctic Lake Laberge Yukon |
geographic_facet |
Arctic Lake Laberge Yukon |
genre |
Arctic Burbot Lake Laberge Northern pike Phytoplankton Zooplankton Yukon |
genre_facet |
Arctic Burbot Lake Laberge Northern pike Phytoplankton Zooplankton Yukon |
op_relation |
Ryan, M.J., G.A. Stern, M.V. Croft, K. Kidd, M. Diamond and P. Roach (2005). Temporal Trends of Organochlorine Contaminants in Burbot and Lake trout from Three Selected Yukon Lakes. Sci. Tot. Environ. 351-352: 501-522 http://hdl.handle.net/1993/227 |
op_rights |
open access |
_version_ |
1769004385818378240 |