Development of a Simple Morphometric Model to Identify Sex in Chinook Salmon Returning to Spawn in the Yukon River

2021 ◽  
Author(s):  
Catherine A. Bradley ◽  
Randy J. Brown
Keyword(s):  
Chinook Salmon ◽  
Yukon River

Effect of Ichthyophonus on blood plasma chemistry of spawning Chinook salmon and their resulting offspring in a Yukon River tributary

2017 ◽  
Vol 122 (3) ◽  
pp. 223-236 ◽  
Author(s):  
TP Floyd-Rump ◽  
LA Horstmann-Dehn ◽  
S Atkinson ◽  
C Skaugstad
Keyword(s):  
Blood Plasma ◽  
Chinook Salmon ◽  
Plasma Chemistry ◽  
Yukon River

Using thalweg profiling to assess and monitor juvenile salmon (Oncorhynchus spp.) habitat in small streams

2006 ◽  
Vol 63 (7) ◽  
pp. 1515-1525 ◽  
Author(s):  
Brent Mossop ◽  
Michael J Bradford
Keyword(s):  
Chinook Salmon ◽  
Stream Flow ◽  
Gold Mining ◽  
Oncorhynchus Tshawytscha ◽  
Fish Habitat ◽  
Juvenile Chinook Salmon ◽  
Yukon River ◽  
Small Streams ◽  
Longitudinal Profiles ◽  
Small Tributary

Thalweg profiles are longitudinal profiles of the streambed elevation measured along the deepest portion of the stream. This technique has recently been advocated as a tool to assess and monitor fish habitat in streams because metrics calculated from thalweg profiles can provide useful information on habitat quality, and measurements are both repeatable and independent of stream flow. Relations between thalweg metrics and land use have also been documented. However, a relation between fish abundance and thalweg metrics has not been established. To develop this relation, we surveyed thalweg profiles and sampled juvenile Chinook salmon (Oncorhynchus tshawytscha) density in 14 reaches of small tributary streams of the upper Yukon River. Chinook salmon density was correlated with three thalweg metrics. Two of these metrics — length in residual pool and mean maximum residual pool depth — provided useful measures of pool extent and quality and useful information on Chinook salmon habitat. Thalweg metrics differed between these undisturbed streams and reaches in streams affected by placer gold mining. These results suggest that thalweg profiling provides a useful tool to assess and monitor fish habitat in small streams.

scholarly journals Environmental controls of phenology of high-latitude Chinook salmon populations of the Yukon River, North America, with application to fishery management

2011 ◽  
Vol 68 (6) ◽  
pp. 1155-1164 ◽  
Author(s):  
Phillip R. Mundy ◽  
Danielle F. Evenson
Keyword(s):  
Global Warming ◽  
Environmental Factors ◽  
High Latitude ◽  
Chinook Salmon ◽  
Fishery Management ◽  
Sea Surface ◽  
Environmental Controls ◽  
Yukon River ◽  
Air Temperatures ◽  
Migratory Timing

Abstract Mundy, P. R., and Evenson, D. F. 2011. Environmental controls of phenology of high-latitude Chinook salmon populations of the Yukon River, North America, with application to fishery management. – ICES Journal of Marine Science, 68: 1155–1164. Phenologies of a number of anadromous fish species have been demonstrated to vary in concert with environmental factors that change with global warming, such as water and air temperatures. Anadromous fishery managers will need advice from models of phenology, or migratory timing, as functions of environmental factors in those harvest areas where annual migratory timing can vary sharply. Such models are also necessary to advise fishery managers on how and when global warming projections of the IPCC model ensemble should be factored into regulatory decisions. Specifically, we demonstrate that the annual timing of marine exit of Yukon River Chinook salmon (Oncorhynchus tshawytscha) at 63°N 165°W for 1961–2009 varied in close concert with modelled sea surface temperature, air temperature, and sea ice cover. The best linear model for 1961–2009 combines sea surface and air temperatures to explain 59% of the annual variability in migratory timing (ice cover is available only for 1970–2009). Changes in phenology of high-latitude Chinook salmon are expected in response to global warming. As average temperatures increase, the frequency of earlier migrations is expected to increase, making management of the fishery more challenging.

Low productivity of Chinook salmon strongly correlates with high summer stream discharge in two Alaskan rivers in the Yukon drainage

2015 ◽  
Vol 72 (8) ◽  
pp. 1125-1137 ◽  
Author(s):  
Jason R. Neuswanger ◽  
Mark S. Wipfli ◽  
Matthew J. Evenson ◽  
Nicholas F. Hughes ◽  
Amanda E. Rosenberger
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Population Declines ◽  
Environmental Predictors ◽  
High Discharge ◽  
Stream Discharge ◽  
Yukon River ◽  
Stock Recruitment ◽  
Sources Of Variation ◽  
Major Floods

Yukon River Chinook salmon (Oncorhynchus tshawytscha) populations are declining for unknown reasons, creating hardship for thousands of stakeholders in subsistence and commercial fisheries. An informed response to this crisis requires understanding the major sources of variation in Chinook salmon productivity. However, simple stock–recruitment models leave much of the variation in this system’s productivity unexplained. We tested adding environmental predictors to stock–recruitment models for two Yukon drainage spawning streams in interior Alaska — the Chena and Salcha rivers. Low productivity was strongly associated with high stream discharge during the summer of freshwater residency for young-of-the-year Chinook salmon. This association was more consistent with the hypothesis that sustained high discharge negatively affects foraging conditions than with acute mortality during floods. Productivity may have also been reduced in years when incubating eggs experienced major floods or cold summers and falls. These freshwater effects — especially density dependence and high discharge — helped explain population declines in both rivers. They are plausible as contributors to the decline of Chinook salmon throughout the Yukon River drainage.

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