Feasibility Report For: Landscape-scale Analysis of the Relationship Between Juvenile Chinook Size and Growth and Stream Temperature in Western Alaska PDF Download

Author: Suresh A. Sethi
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 16

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Book Description
Skin temperature data were produced using a well-vetted method for generating radiometric surface termperatures using NASA Landsat thermal imergery. In examining the juvenile salmon forklength and temperature products, the authors feel confident in the ability to examine the interaction between juvenile chinook salmon ecology and freshwater temperatures in Alaska at the landscape scale.

Author: Benjamin Everett Meyer
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 240

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Book Description
Changes in temperature and precipitation as a result of ongoing climate warming in south-central Alaska are affecting juvenile salmon rearing habitat differently across watersheds. Work presented here simulates summer growth rates of juvenile Chinook and coho salmon in streams under future climate and feeding scenarios in the Kenai River (Alaska) watershed across a spectrum of landscape settings from lowland to glacially-influenced. I used field-derived data on water temperature, diet, and body size as inputs to bioenergetics models to simulate growth for the 2030-2039 and 2060-2069 time periods, comparing back to 2010-2019. My results suggest decreasing growth rates under most future scenarios; predicted changes were of lower magnitude in the cooler glacial watershed and main stem and more in montane and lowland watersheds. The results demonstrate how stream and landscape types differentially filter a climate signal to juvenile rearing salmon habitat and contribute to a broader portfolio of habitats in early life stages. Additionally, I examined two years of summer water temperature data from sites throughout our study tributaries to assess the degree to which lower-reach sites are representative of upstream thermal regimes. I found that the lower reaches in the lowland and glacial study watersheds were reasonably representative of daily and seasonal main stem thermal conditions upstream, while in the montane study watershed (elevation and gradient mid-way between the lowland watershed) upstream conditions were less consistent and thus less suitable for thermal characterization by a lower-reach site alone. Together, this work highlights examples of the importance of accounting for habitat diversity when assessing climate change impacts to salmon-bearing streams.

Author: Kathrine G. Howard
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 85

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Book Description
Long-term monitoring of juvenile Chinook salmon Oncorhynchus tshawytscha is needed to identify recruitment and mortality processes, to understand early marine biology and ecology, and develop tools useful for fisheries management. A sampling program for Yukon River salmon was established in the northern Bering Sea in 2003 but annual sampling has been tenuous due to funding limitations. This project was designed to maintain the sampling program for Yukon River stocks, develop a genetic baseline to identify Yukon River stocks, and evaluate a lower cost survey alternative using a smaller vessel and trawl configuration. Results indicated that the genetic baseline can identify four groups of populations from Western Alaska, the two vessel/trawl configurations provided similar estimates of juvenile Chinook salmon abundance (within 20%); however, sea state limitations of the small vessel required an earlier survey timing (August rather than September). The change in survey timing contributed to differences in the spatial distribution and length of salmon caught during the 2 surveys. Surveys identified above average juvenile Chinook salmon abundance during 2014-2016 and above average juvenile abundance per spawner in 2014 and 2015. Both indicate an improvement to the recent poor production of Yukon River Chinook salmon, because juvenile abundance in the northern Bering Sea is known to be a leading indicator of adult returns for this stock. Sampling 2 different time periods provided additional insight into the early marine growth rates of juvenile Yukon River Chinook and other salmon species. Average Chinook salmon growth rate was 1.55 mm per day from marine entry to August, and 1.06 mm per day from August through September. This project represents a critical step to enable the long-term monitoring of juvenile Chinook salmon in Western Alaska and continued pursuit of factors that determine productivity and cohort strength of Yukon River Chinook salmon.

Author: Olivia N. Edwards
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 0

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Book Description
Chinook Salmon Oncorhynchus tshawytscha have experienced population declines across their range in recent decades, including Alaska where they are a critical subsistence, commercial, and sport fish species. The Alaska Board of Fisheries has listed Yukon River Chinook salmon as a “stock of yield concern” since 2000 prompting the implementation of escapement goals for key spawning tributaries in 2001. Additionally, research efforts across the basin have increased to better understand potential mechanisms behind these declines and provide information to facilitate management decisions. To help fill a critical data gap in the overall understanding of the fishery, this research investigated various freshwater juvenile life history factors including patterns in post-emergence summer body size, movement, and fish size during spring outmigration in the Chena River, Alaska. This research also identified links between these biological factors and freshwater processes that are affected by climate change, including stream temperature and discharge, with the intention of documenting benchmark information as conditions continue to change. Juvenile Chinook Salmon movement among four key rearing areas was observed during summer and fall 2019 and early spring 2020. Despite differences in early summer size patterns, by the end of September mean fork lengths were not statistically different among all rearing areas (ANOVA; all P > 0.05). Additionally, mean September weight varied among six years of empirical data and ranged from 3.19 g in 2018 (0.03 SE) to a maximum of 5.10 g in 2009 (0.05 SE). September weight was simulated across years with variable stream temperatures and discharge (2003 to 2020) using a bioenergetics model, and compared to observed data. Weight simulations were within

Author: Justin M. Leon
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 162

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Book Description
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.

Author: Alaska. Division of Fisheries Rehabilitation, Enhancement, and Development
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 14

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Author: Douglas N. McBride
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 64

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Author: Brian Michael Walker
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 104

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Book Description
Freshwater growth of juvenile Chinook salmon Oncorhynchus tshawytscha influences survival and recruitment to the adult population. Retrospective analysis is used to measure salmon growth at previous ages, with fish size and growth assumed to be accurately reflected by otolith increments and scale circuli. I conducted a 122-d laboratory experiment to validate the relationship among body size, growth, and width to daily otolith growth increments and scale circuli in juvenile stream-type Chinook salmon. Fish total length was found to be proportional to otolith axis length (r2 = 0.209, p

Author: Megan Tyler Perry
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 152

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Book Description
In management of Pacific salmon, it is often assumed that density-dependent factors, mediated by the physical environment during freshwater residency, regulate population size prior to smolting and outmigration. However, in years following low escapement, temperature may be setting the upper limit on growth of juvenile chinook salmon Oncorhynchus tshawytscha during the summer rearing period. Given the importance of juvenile salmon survival for the eventual adult population size, we require a greater understanding of how density-dependent and independent factors affect juvenile demography through time. In this study we tested the hypotheses that (1) juvenile chinook salmon in the Chena River are food limited, and (2) that freshwater growth of juvenile chinook salmon is positively related with marine survival. We tested the first hypotheses using an in-situ supplemental feeding experiment, and the second hypothesis by conducting a retrospective analysis on juvenile growth estimated using a bioenergetics model related to return per spawner estimates from a stock-recruit analysis. We did not find evidence of food limitation, nor evidence that marine survival is correlated with freshwater growth. However, we did find some evidence suggesting that growth during the freshwater rearing period may be limited by food availability following years when adult escapement is high.

Author: Julie Koppel Maldonado
Publisher: Springer
ISBN: 3319052667
Category : Science
Languages : en
Pages : 178

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Book Description
With a long history and deep connection to the Earth’s resources, indigenous peoples have an intimate understanding and ability to observe the impacts linked to climate change. Traditional ecological knowledge and tribal experience play a key role in developing future scientific solutions for adaptation to the impacts. The book explores climate-related issues for indigenous communities in the United States, including loss of traditional knowledge, forests and ecosystems, food security and traditional foods, as well as water, Arctic sea ice loss, permafrost thaw and relocation. The book also highlights how tribal communities and programs are responding to the changing environments. Fifty authors from tribal communities, academia, government agencies and NGOs contributed to the book. Previously published in Climatic Change, Volume 120, Issue 3, 2013.