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dc.contributor.authorGatt, Kyle P.
dc.date.accessioned2021-11-28T21:17:37Z
dc.date.available2021-11-28T21:17:37Z
dc.date.issued2021-05
dc.identifier.urihttp://hdl.handle.net/11122/12549
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2021en_US
dc.description.abstractAccurate 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 structure of juvenile whitefishes.en_US
dc.description.sponsorshipHilcorp Alaskaen_US
dc.language.isoen_USen_US
dc.subjectArctic ciscoen_US
dc.subjectAge determinationen_US
dc.subjectBeaufort Sea Coasten_US
dc.subjectGrowthen_US
dc.subjectWhitefishesen_US
dc.subjectLeast ciscoen_US
dc.subjectBroad whitefishen_US
dc.subjectHumpback whitefishen_US
dc.subjectOtolithsen_US
dc.subject.otherMaster of Science in Fisheriesen_US
dc.titleAssessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environmenten_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Fisheriesen_US
dc.contributor.chairSutton, Trent M.
dc.contributor.committeevon Biela, Vanessa R.
dc.contributor.committeeMcPhee, Megan V.
refterms.dateFOA2021-11-28T21:17:38Z


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