Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment
Thesis (M.S.) University of Alaska Fairbanks, 2021 Accurate monitoring of population-level health and productivity is essential for assessing the status and availability of subsistence harvested species at the forefront of climate change. This study used otolith biochronology to assess the long-term...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/12549 2023-05-15T14:30:15+02:00 Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment Gatt, Kyle P. Sutton, Trent M. von Biela, Vanessa R. McPhee, Megan V. 2021-05 http://hdl.handle.net/11122/12549 en_US eng http://hdl.handle.net/11122/12549 Department of Fisheries Arctic cisco Age determination Beaufort Sea Coast Growth Whitefishes Least cisco Broad whitefish Humpback whitefish Otoliths Master of Science in Fisheries Thesis ms 2021 ftunivalaska 2023-02-23T21:37:57Z Thesis (M.S.) University of Alaska Fairbanks, 2021 Accurate monitoring of population-level health and productivity is essential for assessing the status and availability of subsistence harvested species at the forefront of climate change. This study used otolith biochronology to assess the long-term growth response of Arctic Cisco Coregonus autumnalis during a period of rapid environmental change in the Beaufort Sea region and to identify drivers of growth. A biochronology spanning 22 years (1996-2018) revealed significant interannual variation, with faster growth rates in years with warmer (R² = 0.31) and more saline (R² = 0.47) waters during the ice-free summer feeding period (July-September). These results suggested that warming may benefit Arctic Cisco. This study also compared age estimates made using fin rays, scales, and otoliths of four subsistence whitefishes (Arctic Cisco, Least Cisco Coregonus sardinella, Broad Whitefish Coregonus nasus, and Humpback Whitefish Coregonus pidschian) from the Beaufort Sea to compare the aging precision of non-lethal structures (fin rays and scales) to otoliths. Fin rays and scales provided similar age estimates as otoliths until the age of sexual maturity and underestimated otolith age for mature individuals. Scales underestimated age more often and were more difficult to which to assign age than the other two structures. Among Arctic Cisco in Alaska, fin rays and scales provided similar age estimates as otoliths for all age and size classes examined because most individuals in the study area were immature fish. These results suggested that dorsal fin rays may be used to estimate age in Least Cisco <300 mm, Broad Whitefish <450 mm, and Humpback Whitefish <350 mm, and that otoliths should remain the primary aging structure for the largest whitefishes. Overall, this research complements existing monitoring by providing evidence of an Arctic subsistence species that may benefit in part from warming and highlights non-lethal alternatives for monitoring the age ... Thesis Arctic cisco Arctic Beaufort Sea Climate change Coregonus autumnalis Coregonus pidschian Humpback whitefish pidschian Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Arctic cisco Age determination Beaufort Sea Coast Growth Whitefishes Least cisco Broad whitefish Humpback whitefish Otoliths Master of Science in Fisheries |
spellingShingle |
Arctic cisco Age determination Beaufort Sea Coast Growth Whitefishes Least cisco Broad whitefish Humpback whitefish Otoliths Master of Science in Fisheries Gatt, Kyle P. Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
topic_facet |
Arctic cisco Age determination Beaufort Sea Coast Growth Whitefishes Least cisco Broad whitefish Humpback whitefish Otoliths Master of Science in Fisheries |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2021 Accurate monitoring of population-level health and productivity is essential for assessing the status and availability of subsistence harvested species at the forefront of climate change. This study used otolith biochronology to assess the long-term growth response of Arctic Cisco Coregonus autumnalis during a period of rapid environmental change in the Beaufort Sea region and to identify drivers of growth. A biochronology spanning 22 years (1996-2018) revealed significant interannual variation, with faster growth rates in years with warmer (R² = 0.31) and more saline (R² = 0.47) waters during the ice-free summer feeding period (July-September). These results suggested that warming may benefit Arctic Cisco. This study also compared age estimates made using fin rays, scales, and otoliths of four subsistence whitefishes (Arctic Cisco, Least Cisco Coregonus sardinella, Broad Whitefish Coregonus nasus, and Humpback Whitefish Coregonus pidschian) from the Beaufort Sea to compare the aging precision of non-lethal structures (fin rays and scales) to otoliths. Fin rays and scales provided similar age estimates as otoliths until the age of sexual maturity and underestimated otolith age for mature individuals. Scales underestimated age more often and were more difficult to which to assign age than the other two structures. Among Arctic Cisco in Alaska, fin rays and scales provided similar age estimates as otoliths for all age and size classes examined because most individuals in the study area were immature fish. These results suggested that dorsal fin rays may be used to estimate age in Least Cisco <300 mm, Broad Whitefish <450 mm, and Humpback Whitefish <350 mm, and that otoliths should remain the primary aging structure for the largest whitefishes. Overall, this research complements existing monitoring by providing evidence of an Arctic subsistence species that may benefit in part from warming and highlights non-lethal alternatives for monitoring the age ... |
author2 |
Sutton, Trent M. von Biela, Vanessa R. McPhee, Megan V. |
format |
Thesis |
author |
Gatt, Kyle P. |
author_facet |
Gatt, Kyle P. |
author_sort |
Gatt, Kyle P. |
title |
Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
title_short |
Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
title_full |
Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
title_fullStr |
Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
title_full_unstemmed |
Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment |
title_sort |
assessing the long-term growth response and age estimation precision for arctic whitefishes in a rapidly changing nearshore environment |
publishDate |
2021 |
url |
http://hdl.handle.net/11122/12549 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic cisco Arctic Beaufort Sea Climate change Coregonus autumnalis Coregonus pidschian Humpback whitefish pidschian Alaska |
genre_facet |
Arctic cisco Arctic Beaufort Sea Climate change Coregonus autumnalis Coregonus pidschian Humpback whitefish pidschian Alaska |
op_relation |
http://hdl.handle.net/11122/12549 Department of Fisheries |
_version_ |
1766304133079367680 |