Download or read book Effect of Density dependent Marine Growth on the Economically Optimal Lake Enrichment Strategy for British Columbia Sockeye Salmon Oncorhynchus Nerka microform written by Guthrie, Ian C. (Ian Campbell) and published by National Library of Canada. This book was released on 1985 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Smolt Size and Marine Growth Rates on Adult Sockeye Salmon Oncorhynchus Nerka Returns and Possible Implications for the Cost written by Ryall, Paul J. (Paul James) and published by National Library of Canada. This book was released on 1985 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Bayesian Benefit cost Analysis of an Experimental Fertilization Project for Sockeye Salmon Oncorhynchus Nerka in Chilko Lake British Columbia microform written by Marla Rae Maxwell and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2000 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Gulf of Alaska Sockeye Salmon Oncorhynchus Nerka Abundance on Survival Body Size Growth Rate and Age at Maturity of British Columbia and Britol Bay Alaska Sockeye Populations written by Canada. Department of Fisheries and Oceans and published by . This book was released on 1984 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Gulf of Alaska Sockeye Salmon Oncorhynchus Nerka Abundance on Survival Body Size Growth Rate and Age at Maturity of British Columbia and Bristol Bay Alaska Sockeye Populations written by Canada. Department of Fisheries and Oceans and published by Fisheries and Oceans, Canada. This book was released on 1984 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Contribution of Environment and Heredity to Differences in Freshwater Growth Between Birkenhead River and Weaver Creek Sockeye Salmon Oncorhynchus Nerka microform written by James Douglas Cave and published by National Library of Canada. This book was released on 1988 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Factors Influencing the Early Marine Ecology of Juvenile Sockeye Salmon O Nerka in Rivers Inlet British Columbia written by Seana Leigh Buchanan and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Rivers Inlet sockeye salmon (Oncorhynchus nerka) population was historically the third most numerous in British Columbia, with returns routinely exceeding one million adults. In recent years, the population has drastically declined, culminating in an utter failure of the adult spawning population in 1999, when returns were estimated at 3600 fish. Poor marine survival has been proposed as the primary cause of the decline. Existing evidence, including concurrent declines in sockeye salmon populations from nearby watersheds indicate the problem may lie in the early marine phase. We provide evidence suggesting that a crucial, population-limiting window may exist in the early marine phase, as the newly smolted juvenile sockeye salmon emerge into Rivers Inlet and nearby waters. Unless appropriate abiotic conditions exist in the lead-up to the juvenile migration, the brood year may suffer significant mortality. This, I propose, is a key contributor to reduced returns of Rivers Inlet sockeye salmon.
Download or read book Studies of the Limnological Factors Affecting the Propagation and Survival of the Sockeye Salmon written by William Edwin Ricker and published by . This book was released on 1935 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Lake Fertilization on Growth of Juvenile Sockeye Salmon Oncorhynchus Nerka Walbaum in Lake McDonald Tongass National Forest Alaska written by Ronald P. Olson and published by . This book was released on 1989 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Purpose of this study was to measure the effect of lake fertilization on growth of juvenile sockeye salmon (Oncorhynchus nerka Walbaum) in Lake McDonald, Tongass National Forest, Alaska. Lake was fertilized to increase phosphorus base load.
Download or read book Linking Freshwater Growth to Size dependent Marine Survival of Sockeye Salmon written by Marta Elizabeth Ree and published by . This book was released on 2019 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the mediating role of body size in determining fitness, the ‘bigger is better’ hypothesis still pervades evolutionary ecology despite evidence that natural selection on phenotypic traits varies in time and space. For Pacific salmon (genus Oncorhynchus), the size at which juveniles migrate to sea (i.e., smolts) has been linked to survival during the early marine period, where larger smolts typically survive at a higher rate than their smaller counterparts. However, the relationship of smolt size and survival becomes more ambiguous when considering confounding factors of age, ocean entry timing, and environmental variability. Despite equivocal results, smolt size appears to be a key trait and therefore changes in freshwater conditions may have consequences for population productivity. Furthermore, due to differences in site-specific habitats, trophic dynamics, and population traits the response of specific populations to these changes is likely to be context specific. The objective of this thesis was to 1) quantify the direction and magnitude of natural selection on smolt size for three age classes of sockeye salmon in a small watershed on Kodiak Island, AK and 2) explore stock-specific effects of temperature and conspecific density on smolt size over a multi-decade time-series to understand historic and possible future trends. To address our first objective, we calculated standardized selection differentials by comparing observed size distributions of out-migrating juvenile salmon to back-calculated smolt length from the scales of surviving, returning adults. Results reveal the magnitude of selection on size was very strong and consistent among years. However, the direction of selection on size consistently varied among age classes. The absolute magnitude of selection was negatively correlated to apparent marine survival and positively correlated to late mean ocean entry timing. To address our second objective, we back-calculated smolt size from returning adult scales to reconstruct a time-series of smolt length of two stocks within a small Alaska watershed on Kodiak Island. Using a dynamic linear model framework, we detected evidence that for one stock, temperature was important in explaining smolt length, and density effects influenced both stocks utilizing the same lakes. Furthermore, forecasts of smolt length showed highly variable responses under scenarios of increasing temperature and high and low densities. Collectively, these results demonstrate that interactions between processes of climate, density, and natural selection are highly context-specific in terms of both inter- and intra- population variability.
Download or read book Increased Predation by Juvenile Sockeye Salmon Oncorhynchus Nerka Walbaum Relative to Changes in Macrozooplankton Abundance in Babine Lake British Columbia written by David Paul Rankin and published by . This book was released on 1977 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Benefit cost Evaluation of a Sockeye Salmon Oncorphynchus Nerka Hatchery on the Nahmint River British Columbia microform written by Bruce A. (Bruce Anthony) White and published by National Library of Canada. This book was released on 1988 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lake Fertilization written by John G. Stockner and published by . This book was released on 1987 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sedimentary Legacy of Sockeye Salmon oncorhynchus Nerka and Climate Change in an Ultra oligotrophic Glacially turbid British Columbia Nursery Lake written by Aaron C. Hill and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Marine derived Nutrients on Population Dynamics of Sockeye Salmon Oncorhynchus Nerka written by Tadayasu Uchiyama and published by . This book was released on 2006 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The effects of marine-derived nutrients (MDN) on the productivity of sockeye salmon (Oncorhynchus nerka) stocks in Alaska were examined through nitrogen stable isotope analysis of smolts and mathematical models of the sockeye stock-recruit relationship. Smolt 8 [delta]15N was used to infer the degree to which smolts depend on MDN for their growth. We attempted to identify the characteristics of sockeye nursery lakes and watersheds that affect the availability of MDN to juvenile sockeye using multiple regression. Stock-recruit models incorporating MDN effects were fit to sockeye escapement-return data to test if fluctuations in sockeye stock productivity could be explained by changes in MDN input into nursery lakes. The magnitude of escapement and water residence time were the most important factors affecting the MDN availability to juvenile salmon. Mixing state of lakes and the distance from the coast were also found to significantly affect the MDN availability. We found that regional environmental fluctuations had a large effect on stock productivities in stock-recruit modeling. However, we did not find strong evidence to support our hypothesis that increases in MDN input to nursery lakes will result in increased productivity of sockeye stocks. Stock-recruitment data may be poorly suited to detection of the influence of MDN"--Leaf iii.
Download or read book Preliminary Results of Studies on the Effects of Fertilization of an Oligotrophic Lake on Adult Sockeye Salmon oncorhynchus Nerka Production written by Canada. Fisheries and Marine Service. Research and Development Directorate and published by nanaimo, b. c. : pacific biological station, fisheries and marine service. This book was released on 1976 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
