Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis.
Thesis (M.S.) University of Alaska Fairbanks, 2013 Chinook salmon Oncorhynchus tshawytscha recruitment in the Yukon and Kuskokwim (Y-K) region of western Alaska is important for subsistence and commercial harvest. Recruitment of Chinook salmon in this region has been unpredictable in recent years, a...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/4294 2023-05-15T17:05:38+02:00 Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. Leon, Justin M. McPhee, Megan Sutton, Trent Adkison, Milo 2013-05 http://hdl.handle.net/11122/4294 unknown http://hdl.handle.net/11122/4294 Fisheries Division Thesis ms 2013 ftunivalaska 2023-02-23T21:36:12Z Thesis (M.S.) University of Alaska Fairbanks, 2013 Chinook salmon Oncorhynchus tshawytscha recruitment in the Yukon and Kuskokwim (Y-K) region of western Alaska is important for subsistence and commercial harvest. Recruitment of Chinook salmon in this region has been unpredictable in recent years, and managers and subsistence harvesters are searching for answers. Chinook salmon require freshwater growth to smolt, and larger smolts are thought to have higher marine survival. In this study, I tested for correlations between freshwater growth and recruitment using measurements from scale digitizations. All analyses were conducted at the tributary scale, with one tributary representing each river system. Linear regressions were used to check for correlations between freshwater growth and Chinook salmon returns (female productivity - recruits per spawner), number and size of female spawners present, marine growth, and water temperature. Tukey multiple comparison tests and stacked bar plots were used to check for correlations between freshwater growth and the age at which females mature and between freshwater growth and early maturation. I found no direct correlation between freshwater growth and recruitment in either tributary. However, freshwater growth appears to be decreasing as time progresses. These results suggest that, while important, freshwater growth is not the factor directly limiting recruitment in either of these tributaries. Thesis Kuskokwim Alaska Yukon University of Alaska: ScholarWorks@UA Yukon Fairbanks |
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University of Alaska: ScholarWorks@UA |
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description |
Thesis (M.S.) University of Alaska Fairbanks, 2013 Chinook salmon Oncorhynchus tshawytscha recruitment in the Yukon and Kuskokwim (Y-K) region of western Alaska is important for subsistence and commercial harvest. Recruitment of Chinook salmon in this region has been unpredictable in recent years, and managers and subsistence harvesters are searching for answers. Chinook salmon require freshwater growth to smolt, and larger smolts are thought to have higher marine survival. In this study, I tested for correlations between freshwater growth and recruitment using measurements from scale digitizations. All analyses were conducted at the tributary scale, with one tributary representing each river system. Linear regressions were used to check for correlations between freshwater growth and Chinook salmon returns (female productivity - recruits per spawner), number and size of female spawners present, marine growth, and water temperature. Tukey multiple comparison tests and stacked bar plots were used to check for correlations between freshwater growth and the age at which females mature and between freshwater growth and early maturation. I found no direct correlation between freshwater growth and recruitment in either tributary. However, freshwater growth appears to be decreasing as time progresses. These results suggest that, while important, freshwater growth is not the factor directly limiting recruitment in either of these tributaries. |
author2 |
McPhee, Megan Sutton, Trent Adkison, Milo |
format |
Thesis |
author |
Leon, Justin M. |
spellingShingle |
Leon, Justin M. Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
author_facet |
Leon, Justin M. |
author_sort |
Leon, Justin M. |
title |
Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
title_short |
Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
title_full |
Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
title_fullStr |
Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
title_full_unstemmed |
Freshwater growth and recruitment of Yukon and Kuskokwim River Chinook salmon: a retrospective growth analysis. |
title_sort |
freshwater growth and recruitment of yukon and kuskokwim river chinook salmon: a retrospective growth analysis. |
publishDate |
2013 |
url |
http://hdl.handle.net/11122/4294 |
geographic |
Yukon Fairbanks |
geographic_facet |
Yukon Fairbanks |
genre |
Kuskokwim Alaska Yukon |
genre_facet |
Kuskokwim Alaska Yukon |
op_relation |
http://hdl.handle.net/11122/4294 Fisheries Division |
_version_ |
1766060330186702848 |