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Book Factors Influencing Chinook Salmon Spawning Distribution in the Togiak River Alaska

Download or read book Factors Influencing Chinook Salmon Spawning Distribution in the Togiak River Alaska written by Stephanie L. Meggers and published by . This book was released on 2018 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salmonids are heavily dependent on specific habitat characteristics for survival, yet few studies in Alaska have examined the relationship between habitat and spawning distribution, using remote sensing approaches. To better understand the relationship between Chinook Salmon Oncorhynchus tshawytscha spawning distribution and environmental variables like habitat type (e.g., run, riffle, pool), temperature, and proximity to channel islands, optical and thermal imagery were collected on the Togiak and Ongivinuk rivers in southwest Alaska. Object-based image analysis was used to classify and quantify habitat types, while thermal characteristics and the proximity of spawning locations to channel islands were determined in a GIS framework. Object-based image analysis was useful for classifying habitat and may provide a better alternative to pixel-based image analysis. However, rule sets were nontransferable and inconsistent among river reaches, and caution should be taken when these methods are used on large river sections. Chinook Salmon showed a preference for spawning in river runs, 80% of fish spawned in water temperatures between 8.6° and 9.4°C, and nearly 61% of Chinook Salmon spawned within 100 m of a channel island. This study provided a baseline understanding of environmental correlates of spawning for Chinook Salmon at the northern extent of their range.

Book Estimation of Chinook Salmon Distribution and Run Timing in the Togiak River Watershed Using Radio Telemetry Togiak National Wildlife Refuge Alaska 2008

Download or read book Estimation of Chinook Salmon Distribution and Run Timing in the Togiak River Watershed Using Radio Telemetry Togiak National Wildlife Refuge Alaska 2008 written by Cheryl A. Anderson and published by . This book was released on 2009 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Estimation of Chinook Salmon Escapement Distribution and Run Timing in the Togiak River Watershed Using Radiotelemetry Togiak National Wildlife Refuge Alaska 2012

Download or read book Estimation of Chinook Salmon Escapement Distribution and Run Timing in the Togiak River Watershed Using Radiotelemetry Togiak National Wildlife Refuge Alaska 2012 written by U.S. Fish and Wildlife Service. Anchorage Fish and Wildlife Field Office and published by . This book was released on 2014 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Factors Affecting the Abundance of Fall Chinook Salmon in the Columbia River

Download or read book Factors Affecting the Abundance of Fall Chinook Salmon in the Columbia River written by Jack M. Van Hyning and published by . This book was released on 1968 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the population ecology of Columbia River fall chinook salmon, Oncorhynchus tshawytscha (Walbaum), was made in an attempt to determine the cause of a serious decline in this run which occurred in the early 1950's. Fluctuations in abundance of major salmon runs the North Pacific were examined to detect any coastwide pattern. Only chinook salmon in Cook Inlet, Alaska, and chum salmon from Oregon to southwestern Alaska showed a similar trend. The following life history stages broken down into pre- and post-decline years were examined: (1) marine life including distribution and migration, growth and maturity, survival rate, oceanography, and commercial and sport fisheries; (2) upstream migration including river fisheries, gear selectivity, size and age composition of the run, escapement, and influence of dams, diseases, and water quality; (3) reproduction and incubation including spawning areas and spawning and incubation conditions; and (4) downstream migration which included predation, dams and reservoirs, diseases, flow, turbidity and temperature, and estuary life. Salient points of the analysis were: (1) a change in the maturity and survival pattern based on tagged and fin-clipped fish recovered before and after 1950; (2) a significant negative correlation between sea-water temperature during a year class' first year at sea and subsequent survival; (3) a large increase in the ocean fisheries coincident with the decline in the run; (4) catch-effort statistics of the ocean fishery show a near classic example of the effect of overexploitation; (5) estimates of the contribution of Columbia River chinook to the ocean fisheries based on tag recoveries could be underestimates rather than overestimates; (6) a significant inverse correlation between estimated ocean catch of Columbia River fall chinook and numbers entering the river; (7) size and age composition of the ocean and river catches decreased coincident with the decline in the run; (8) the gill-net fishery shows little size selectivity by age, size, or sex in the dominant group; (9) fluctuations in abundance of hatchery stocks are related to differences in survival between fingerling and adult; (10) hatchery, lower river, and upriver populations fluctuate in abundance in much the same pattern; (11) optimum escapement is between 90,000 and 100,000 adults, a value that was exceeded during most years; (12) a highly significant negative correlation between numbers of spawners and return per spawner; (13) most of the early dams had no direct effect on fall chinook and the decline in productivity occurred when river conditions were relatively stable; (14) temperatures at time of migration and spawning for fall chinook have not increased enough to be a serious mortality factor; (15) little relationship between flow, turbidity, and temperature at time of downstream migration and subsequent return was evident except that high temperatures and high flows (and turbidities) tended to produce poorer runs during certain time periods; and (16) predation and delay of smolts in reservoirs are largely unknown factors, but circumstantial evidence suggests that they were not important in regulating fall chinook numbers during the period of the study. Finally, variables that appeared to bear some relationship to fluctuations in abundance of fall chinook were submitted to multiple regression analysis. For the predecline period (1938-46 brood years), sea-water temperature and ocean troll fishing effort were significant variables (R2 = 0.74). For post decline years (1947-59 broods), troll had the most influence on total return with ocean temperature and escapement having lesser effects. For the combined years, troll intensity and ocean temperature were the significant variables (R2 = 0.572). Entering interaction of river flow at downstream migration with the other variables brought R2 to 0.754 which means that 75% of the variability in the returning run could be accounted for by these three factors. Return per spawner was so heavily influenced by numbers of spawners that the other factors assumed negligible importance. Equations were derived that predicted the returning run in close agreement with the actual run size. Substituting a low and constant troll fishing effort in the equation resulted in the predicted run maintaining the average predecline level. The increase in ocean fishing was the main contributor to the decline of the Columbia River fall chinook run as shown by correlation, by analogy, and by the process of elimination. To demonstrate why other chinook runs have not shown similar declines, it was shown that due to several unique features in Columbia River fall chinook life history they are exposed to much more ocean fishing than other populations. It was emphasized that these conclusions should not be extrapolated to the future or to other species or runs of salmon.

Book Analysis of Factors Influencing the Population Dynamics of Chinook Salmon Oncorhynchus Tshawytscha in Central California

Download or read book Analysis of Factors Influencing the Population Dynamics of Chinook Salmon Oncorhynchus Tshawytscha in Central California written by Robert Glenn Kope and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Influence of Freshwater Processes on Juvenile Chinook Salmon Size Movement and Outmigration Timing in the Chena River Alaska

Download or read book Influence of Freshwater Processes on Juvenile Chinook Salmon Size Movement and Outmigration Timing in the Chena River Alaska written by Olivia N. Edwards and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Book Run Timing and Spawning Distribution of Coho and Late Run Chinook Salmon in the Kasilof River Watershed Alaska 1987

Download or read book Run Timing and Spawning Distribution of Coho and Late Run Chinook Salmon in the Kasilof River Watershed Alaska 1987 written by Dave Faurot and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Distribution of Spawning Susitna River Chinook Oncorhynchus Tshawytscha and Pink Salmon O Gorbuscha 2012

Download or read book Distribution of Spawning Susitna River Chinook Oncorhynchus Tshawytscha and Pink Salmon O Gorbuscha 2012 written by Richard Yanusz and published by . This book was released on 2013 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study is to determine the spawning distribution of chinook salmon in the Susitna drainage upstream of the confluence with the Yentna River as well as the spawning distribution of pink salmon in the entire Susitna drainage. The information collected during the 2012 field season will be used to address the feasibility of conducting a basin-wide capture-recapture study of chinook salmon in 2013 and 2014.

Book River Features Associated with Chinook Salmon Spawning Habitat in Southwest Alaska

Download or read book River Features Associated with Chinook Salmon Spawning Habitat in Southwest Alaska written by Deena M. Jallen and published by . This book was released on 2009 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Chinook salmon Oncorhynchus tshawytscha are a highly valued traditional, subsistence, and commercial resource in southwest Alaska. Stream habitat availability is a major component influencing salmon productivity. The objective of this study is to identify river features associated with spawning habitat, and describe upper and lower boundaries of Chinook salmon spawning on the Tuluksak River. River distances, elevation, salmon locations, spawning sites, and habitat observations were collected along 75 rkm (river kilometers) of the Tuluksak River primarily within the Yukon Delta National Wildlife Refuge. Habitat and salmon observations were grouped into strata along the length of the river for comparison and analysis. Chinook salmon were observed spawning in the upper 45 rkm of the study area. Map-based observations of elevation and channel sinuosity correlate better with Chinook salmon spawning than in stream habitat measurements along the Tuluksak River. The upper boundary of Chinook salmon spawning in the Tuluksak River was outside of our study area. The lower boundary for Chinook salmon spawning habitat on similar rivers might be determined by examining elevation, sinuosity, and channel features from remote images or maps prior to conducting field studies"--Leaf iii.

Book Production and Spawning Distribution of Chilkat River Chinook Salmon in 2005

Download or read book Production and Spawning Distribution of Chilkat River Chinook Salmon in 2005 written by Randolph P. Ericksen and published by . This book was released on 2006 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to estimate the sport harvest, escapement, spawning distribution, and production of Chinook salmon, Oncorhynchus tshawytscha, returning to the Chilkat River during 2005.

Book Gulkana River Chinook Salmon Distribution

Download or read book Gulkana River Chinook Salmon Distribution written by Corey J. Schwanke and published by . This book was released on 2013 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study estimates the spawning distribution and run timing patterns of Chinook salmon in the Gulkana River and it also estimates proportions of Chinook salmon spawning above and below the counting tower. The study also discusses age, sex, and length (ASL) information collected from Chinook salmon. This information is used to characterize the composition of the Chinook salmon escapement and use that information in an age-structured model to evaluate the escapement goal and forecast returns.

Book Abundance Distribution and Surveys of Spawning Chinook Salmon 2012 2014 and Spawning Coho Salmon 2013 2014 in the Susitna River

Download or read book Abundance Distribution and Surveys of Spawning Chinook Salmon 2012 2014 and Spawning Coho Salmon 2013 2014 in the Susitna River written by Richard J. Yanusz and published by . This book was released on 2018 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Between 2012 and 2014, information was collected on the distributions and abundances of adult Chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon as part of the Susitna-Watana Hydro studies conducted by the Alaska Department of Fish and Game in partnership with LGL Alaska Research Associates Inc. and the Alaska Energy Authority. Spawning distributions were assessed using radiotelemetry for Chinook salmon in the mainstem Susitna River in 2012-2014 and in the Yentna River in 2013 and 2014, and for coho salmon in the mainstem Susitna River in 2013 and 2014 only. Inriver abundances for both species were estimated using mark-recapture techniques in 2013 and 2014 for the mainstem Susitna River and for Chinook salmon in the Yentna River in 2014. For Chinook salmon, these abundance estimates were combined with telemetry data to estimate individual management unit-specific abundances which were then used to calculate the percent contribution of each to total abundance. In both 2013 and 2014, all units but unit 3 (upper Susitna River) contributed nearly equally (21-27%) to the total mainstem Susitna River Chinook salmon inriver run. When the Yentna River estimate was included with estimates for the other management units in 2014, the Yentna River contributed 25% to the drainagewide inriver run; units 1, 2, 5, and 6 contributed 15-19% each; and unit 3 contributed 7%. Sport harvest was subtracted from the mark-recapture inriver abundance to estimate escapement which was then compared to aerial indexes and weir counts. For Chinook salmon, index and weir counts counted 34-39% of the escapement on the mainstem Susitna River and 36% on the Yentna River. For coho salmon, the Deshka River weir counted 19% and 16% of the Sustina River escapements in 2013 and 2014, respectively. Foot counts of coho salmon escapement for 4 streams on the mainstem Susitna River accounted for an average of 0.9% of the escapement over 2013-2014.

Book Gulkana River Chinook Salmon Spawning Distribution and Run Timing 2013 2015

Download or read book Gulkana River Chinook Salmon Spawning Distribution and Run Timing 2013 2015 written by Corey J. Schwanke and published by . This book was released on 2018 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chinook salmon were radiotagged near the confluence of the Gulkana and Copper rivers from 2013-2015 to determine run timing and spawning distribution in the Gulkana River. The main goal was estimating what proportion of the Chinook salmon escapement spawned above an ADF&G operated counting tower located approximately 79.5 rkm up the Gulkana River. Age, sex, and length composition of the escapement was also estimated. A total of 412 Chinook salmon were radiotagged from 2013?2015 using dip nets and hook and line as capture gear. The proportion of Chinook salmon that spawned above the ADF&G counting tower was 0.51 (SE = 0.072) in 2013, 0.45 (SE = 0.073) in 2014, and 0.54 (SE = 0.038) in 2015. Fish spawning above the ADF&G counting tower had a slightly earlier run timing than fish spawning below the counting tower with annual mean dates of passage past the lowest inriver tracking station being 0?7 days earlier. Further examining run timing by river reach, Chinook salmon that spawned in the tributaries and upper mainstem of the Gulkana River had earlier run timing than those spawning in the middle to lower mainstem. The estimated percentage of females that spawned above the counting tower varied by year. Females comprised an estimated 53% (SE = 6%) of the escapement in 2013, 29% (SE = 10%) in 2014, and 51% (SE = 4%) in 2015. Age-1.3 Chinook salmon was the most abundant age class, accounting for 81% (SE = 5%) of the estimated escapement in 2013, 48% (SE = 6%) in 2014, and 88% (SE = 3%) in 2015. Chinook salmon in the length class 751-850 mm mid eye to tail fork accounted for the majority of the estimated annual escapement, ranging between 46% (SE = 6%) and 63% (SE = 4%). This study found several positive relationships with fish traits (e.g., sex, length, and run timing) and spawning success specific to the Gulkana River. Male fish, longer fish, and fish with earlier run timings all had better chances of spawning during this study.