Download or read book An Assessment of the Downstream Migration of Juvenile Chinook Salmon oncorhynchus Tshawytscha in the Lower Mokelumne River California written by Michelle Workman and published by . This book was released on 1999 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mokelumne River Hearing Before the State Water Resources Control Board written by and published by . This book was released on 1992 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Analysis of Juvenile Chinook Salmon Outmigration Speed and Survival in Response to Habitat Features Sacramento River from Knights Landing to Sacramento California written by Natalie N McNair and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Outmigration is an important life stage for Chinook salmon (Oncorhynchus tshawytscha) survival in the Sacramento River, and yet our understanding of their behavior and needs during this time is limited. To gain a better understanding of their survival and movement rates during outmigration, late fall run Chinook salmon smolts were tracked using acoustic telemetry techniques. Habitat features were measured and quantified throughout the study area to evaluate how Chinook salmon respond to key levee features including shade, instream woody material, and aquatic vegetation. The overall average movement speed through the entire study area was 0.77 m/s with an overall survival of 86%. Based on multiple linear regressions, vegetation was found to have the largest effect on speed with fish slowing down with increased vegetation cover. Shade, river mile, and velocity also had significant effects on movement speeds, but instream woody material was not significant. The result for woody material was surprising since it was anticipated to have a large impact on movement speeds. A positive correlation was found between faster fish movement speeds and higher survival. No evidence of diel movement patterns was found after releasing the fish. These finding can help managers create sites better designed to help Chinook salmon in the Sacramento River system. Results from this paper indicate that the type of woody material being installed might not be appropriate for this life stage of salmon.
Download or read book Estimation of the Number of Juvenile Chinook Salmon Oncorhynchus Tshawytscha Migrating Downstream from Blue Creek California 1989 1992 written by Joseph C. Polos and published by . This book was released on 1997 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book River Estuarine Survival and Migration of Yearling Sacramento River Chinook Salmon Oncorhynchus Tshawytscha Smolts and the Influence of Environment written by Cyril J. Michel and published by . This book was released on 2010 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Draft Environmental Impact Statement report written by and published by . This book was released on 1992 with total page 1066 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Out Migration Survival of Wild Chinook Salmon Oncorhynchus Tshawytscha Smolts from Mill Creek Through the Sacramento River During Drought Conditions written by Jeremy Notch and published by . This book was released on 2017 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once emerged from the gravel after being spawned in natal streams, Chinook salmon spend many months rearing and growing in freshwater before undergoing smoltification and out-migrating to the ocean. This relatively short period of time is considered to be the most vulnerable and dangerous phase in the life cycle of a Pacific salmon. It is during this phase when smolts navigate around many anthropogenic structures and experience environmental stressors while making their way to the ocean. In California's Central Valley, the few remaining wild populations of Chinook salmon (Oncorhynchus tshawytscha) out-migrate through a highly modified riverine and estuary landscape characterized by leveed banks, altered flow and temperature regimes, transformed food webs, and limited floodplain and rearing habitat. Juvenile salmon smolts migrate through these landscapes within a relatively short period of time, requiring them to quickly adapt to changing water conditions and habitat types. Understanding the survival rates of wild smolts from source tributaries to the Pacific Ocean is essential in protecting and restoring these populations from the low abundances currently observed. When faced with drought conditions out-migrating smolts experience low flows, elevated water temperatures and high densities of predators while out-migrating to sea. In order to assess smolt survival during drought conditions in late spring (April-May), 304 wild smolts were acoustically tagged and tracked from Mill Creek (Tehama County) to the Pacific Ocean between 2013 and 2016. Total outmigration survival to the ocean was 0.3% during these years, with only one fish making it to the Golden Gate and the Pacific Ocean. These survival estimates are some of the lowest ever recorded for salmon out-migrating to the Pacific Ocean, with much of the mortality occurring within Mill Creek and the Sacramento River. Cumulative survival through Mill Creek (rkm 452--441) was 68% (+/-12 S.E.), and cumulative survival through the Sacramento River (rkm 441--203) was 7.6% (+/- 16 S.E.) These low survival rates are likely attributed to low flows in Mill Creek and the Sacramento River resulting from critically dry winters between 2013 and 2015, which were reduced even further by water diversions for agriculture in both Mill Creek and the Sacramento River. During periods of higher flow in 2016 survival rates dramatically increased, suggesting that more water in Mill Creek and the Sacramento River is necessary to improve in-river smolt migration survival during the late spring.
Download or read book Ecological Statistics written by Gordon A. Fox and published by Oxford University Press. This book was released on 2015 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application and interpretation of statistics are central to ecological study and practice. Ecologists are now asking more sophisticated questions than in the past. These new questions, together with the continued growth of computing power and the availability of new software, have created a new generation of statistical techniques. These have resulted in major recent developments in both our understanding and practice of ecological statistics. This novel book synthesizes a number of these changes, addressing key approaches and issues that tend to be overlooked in other books such as missing/censored data, correlation structure of data, heterogeneous data, and complex causal relationships. These issues characterize a large proportion of ecological data, but most ecologists' training in traditional statistics simply does not provide them with adequate preparation to handle the associated challenges. Uniquely, Ecological Statistics highlights the underlying links among many statistical approaches that attempt to tackle these issues. In particular, it gives readers an introduction to approaches to inference, likelihoods, generalized linear (mixed) models, spatially or phylogenetically-structured data, and data synthesis, with a strong emphasis on conceptual understanding and subsequent application to data analysis. Written by a team of practicing ecologists, mathematical explanations have been kept to the minimum necessary. This user-friendly textbook will be suitable for graduate students, researchers, and practitioners in the fields of ecology, evolution, environmental studies, and computational biology who are interested in updating their statistical tool kits. A companion web site provides example data sets and commented code in the R language.
Download or read book Survival and Migration Dynamics of Juvenile Chinook Salmon Oncorhynchus Tshawytscha in the Sacramento San Joaquin River Delta written by Russell W. Perry and published by . This book was released on 2010 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lower Snake River Juvenile Salmon Migration Feasibility Report environmental Impact Statement Chapters 1 4 written by and published by . This book was released on 2002 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Downstream Migration of Juvenile Chinook Salmon Without Elevated Gill Na K ATPase Activities written by Richard D. Ewing and published by . This book was released on 1979 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Migratory Characteristics of Juvenile Spring Chinook Salmon in the Willamette River written by and published by . This book was released on 1994 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to examine in detail the migration of juvenile spring chinook salmon (Oncorhynchus tshawytscha) in the Willamette River, Oregon. The authors wanted to determine characteristics of seaward migration of spring chinook smolts in relation to the oxygen supplementation practices at the Oregon Department of Fish and Wildlife (ODFW) Willamette Hatchery and use this information to strengthen the design of the oxygen supplementation project. There is little information available on the effects of oxygen supplementation at hatcheries on the migratory characteristics of juvenile salmon. Such information is required to assess the use of oxygen supplementation as a means of improving hatchery production, its effect on imprinting of juveniles, and finally the return of adults. In the event that oxygen supplementation provides for improved production and survival of juvenile chinook salmon at Willamette Hatchery, background information on the migration characteristics of these fish will be required to effectively utilize the increased production within the goals of the Willamette Fish Management Plan. Furthermore this technology may be instrumental in the goal of doubling the runs of spring Chinook salmon in the Columbia River. While evaluation of success is dependent on evaluation of the return of adults with coded wire tags, examination of the migratory characteristics of hatchery smolts may prove to be equally informative. Through this research it is possible to determine the rate at which individuals from various oxygenation treatment groups leave the Willamette River system, a factor which may be strongly related to adult return rate.
Download or read book Juvenile Chinook Salmon Downstream Migration Investigation written by Al von Finster and published by . This book was released on 1998 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Death of a Salmon written by Ian Geoffrey Brosnan and published by . This book was released on 2014 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: From 2008 to 2011, migrating acoustic-tagged juvenile yearling Chinook salmon smolts (Oncorhynchus tshawytscha) were detected on receivers deployed across the Columbia River and continental shelf at Cascade Head (Oregon), Willapa Bay (Washington), and Vancouver Island (British Columbia). The telemetry data were used to estimate survival and record migration parameters. These were evaluated against oceanographic and freshwater hydrologic variables in statistical and individual-based models. Plume survival was found to be variable, but daily survival rates were more constant and survival was effectively modeled as exponential decay. Correlates of early marine survival that do not have direct effects may act on plume survival by controlling the period of exposure to plume predation. In 2011, half of smolts released were exposed to total dissolved gas levels (TDG) above 120%, the water quality limit for TDG below Columbia River dams. This exposure appears to have negatively affected daily survival rates in the lower river and plume, and has important implications for a proposal to increase the TDG limit to 125% to support spring fish passage. Finally, consistent with the critical size, critical period hypothesis of salmon production, it appears that smolts select habitat to maximize their growth as they migrate north through the plume, rather than selectively using local currents to speed their passage. These findings shed new light on perennial questions in salmon early marine ecology. They lay the groundwork for future research aimed at understanding the effects of changing oceanography and freshwater hydrology on salmon migration and survival.
Download or read book Reconstructing the Migratory Behavior and Long Term Survivorship of Juvenile Chinook Salmon Under Contrasting Hydrologic Regimes written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The loss of genetic and life history diversity has been documented across many taxonomic groups, and is considered a leading cause of increased extinction risk. Juvenile salmon leave their natal rivers at different sizes, ages and times of the year, and it is thought that this life history variation contributes to their population sustainability, and is thus central to many recovery efforts. However, in order to preserve and restore diversity in life history traits, it is necessary to first understand how environmental factors affect their expression and success. We used otolith 87Sr/86Sr in adult Chinook salmon (Oncorhynchus tshawytcha) returning to the Stanislaus River in the California Central Valley (USA) to reconstruct the sizes at which they outmigrated as juveniles in a wetter (2000) and drier (2003) year. We compared rotary screw trap-derived estimates of outmigrant timing, abundance and size with those reconstructed in the adults from the same cohort. This allowed us to estimate the relative survival and contribution of migratory phenotypes (fry, parr, smolts) to the adult spawning population under different flow regimes. Juvenile abundance and outmigration behavior varied with hydroclimatic regime, while downstream survival appeared to be driven by size- and time-selective mortality. Although fry survival is generally assumed to be negligible in this system,>20% of the adult spawners from outmigration year 2000 had outmigrated as fry. In both years, all three phenotypes contributed to the spawning population, however their relative proportions differed, reflecting greater fry contributions in the wetter year (23% vs. 10%) and greater smolt contributions in the drier year (13% vs. 44%). In conclusion, these data demonstrate that the expression and success of migratory phenotypes vary with hydrologic regime, emphasizing the importance of maintaining diversity in a changing climate.
Download or read book The Regional Salmon Outmigration Study survival and Migration Routing of Juvenile Chinook Salmon in the Sacramento San Joaquin River Delta During the Winter of 2008 09 written by U.S. Department Of The Interior and published by CreateSpace. This book was released on 2014-03 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Juvenile Chinook salmon (Oncorhynchus tshawytscha) emigrating from natal tributaries of the Sacramento River may use a number of migration routes to navigate the Sacramento-San Joaquin River Delta (hereafter called "the Delta"), each of which may influence their probability of surviving. We applied a mark-recapture model to data from acoustically tagged juvenile late fall-run Chinook salmon that migrated through the Delta during the winter of 2008-09 to estimate route entrainment, survival, and migration times through the Delta.
Download or read book The Use of a Model System for Studying Seaward Migration of Deschutes River Juvenile Spring Chinook Salmon Oncorhynchus Tshawytscha written by C. E. Hart and published by . This book was released on 1978* with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
