Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Fluctuations In Abundance Of Columbia River Chinook Salmon Oncorhynchus Tschawytscha 1935 45
Download Fluctuations In Abundance Of Columbia River Chinook Salmon Oncorhynchus Tschawytscha 1935 45 full books in PDF, epub, and Kindle. Read online Fluctuations In Abundance Of Columbia River Chinook Salmon Oncorhynchus Tschawytscha 1935 45 ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Fluctuations in Abundance of Columbia River Chinook Salmon, Oncorhynchus Tschawytscha, 1935-45 by : Ralph P. SILLIMAN
Download or read book Fluctuations in Abundance of Columbia River Chinook Salmon, Oncorhynchus Tschawytscha, 1935-45 written by Ralph P. SILLIMAN and published by . This book was released on 1950 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fluctuations in Abundance of Columbia River Chinook Salmon (Oncorhynchus Tschawytscha) by : Ralph P. Silliman
Download or read book Fluctuations in Abundance of Columbia River Chinook Salmon (Oncorhynchus Tschawytscha) written by Ralph P. Silliman and published by . This book was released on 1950 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fluctuations in Abundance of Columbia River Chinook Salmon 1928-54 by : Harold A. Gangmark
Download or read book Fluctuations in Abundance of Columbia River Chinook Salmon 1928-54 written by Harold A. Gangmark and published by . This book was released on 1956 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special Scientific Report written by and published by . This book was released on 1956 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fishery Bulletin of the written by and published by . This book was released on 1947 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis N.O.A.A. Technical Report NMFS SSRF by :
Download or read book N.O.A.A. Technical Report NMFS SSRF written by and published by . This book was released on 1957 with total page 1296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Intraseasonal and Interseasonal Variations in Average Weight of Columbia River Chinook Salmon (Oncorhynchus Tschawytscha), 1939-1945 by : Ralph Parks Silliman
Download or read book Intraseasonal and Interseasonal Variations in Average Weight of Columbia River Chinook Salmon (Oncorhynchus Tschawytscha), 1939-1945 written by Ralph Parks Silliman and published by . This book was released on 1947 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fishery Bulletin of the Fish and Wildlife Service by :
Download or read book Fishery Bulletin of the Fish and Wildlife Service written by and published by . This book was released on 1947 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fishery Publication Index; 1920-54 by : U.S. Fish and Wildlife Service
Download or read book Fishery Publication Index; 1920-54 written by U.S. Fish and Wildlife Service and published by . This book was released on 1955 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fishery Publication Index, 1920-54 : Publication of the Bureau of Fisheries and Fishery Publications of the Fish and Wildlife Service by Series, Authors, and Subjects by : United States. Department of the Interior. Library
Download or read book Fishery Publication Index, 1920-54 : Publication of the Bureau of Fisheries and Fishery Publications of the Fish and Wildlife Service by Series, Authors, and Subjects written by United States. Department of the Interior. Library and published by . This book was released on 1955 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Factors Affecting the Abundance of Fall Chinook Salmon in the Columbia River by : Jack M. Van Hyning
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.
Download or read book Fishery Leaflet written by and published by . This book was released on 1966 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Guide to Literature on Systematic Biology of Pacific Salmon by : Norman J. Wilimovsky
Download or read book Guide to Literature on Systematic Biology of Pacific Salmon written by Norman J. Wilimovsky and published by . This book was released on 1957 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Pacific Salmon Life Histories by : Cornelis Groot
Download or read book Pacific Salmon Life Histories written by Cornelis Groot and published by UBC Press. This book was released on 1991 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific salmon are an important biological and economic resource of countries of the North Pacific rim. They are also a unique group of fish possessing unusually complex life histories. There are seven species of Pacific salmon, five occurring on both the North American and Asian continents (sockeye, pink, chum, chinook, and coho) and two (masu and amago) only in Asia. The life cycle of the Pacific salmon begins in the autumn when the adult female deposits eggs that are fertilized in gravel beds in rivers or lakes. The young emerge from the gravel the following spring and will either migrate immediately to salt water or spend one or more years in a river or lake before migrating. Migrations in the ocean are extensive during the feeding and growing phase, covering thousands of kilometres. After one or more years the maturing adults find their way back to their home river, returning to their ancestral breeding grounds to spawn. They die after spawning and the eggs in the gravel signify a new cycle. Upon this theme Pacific salmon have developed many variations, both between as well as within species. Pacific Salmon Life Histories provides detailed descriptions of the different life phases through which each of the seven species passes. Each chapter is written by a scientist who has spent years studying and observing a particular species of salmon. Some of the topics covered are geographic distribution, transplants, freshwater life, ocean life, development, growth, feeding, diet, migration, and spawning behaviour. The text is richly supplemented by numerous maps, illustrations, colour plates, and tables and there is a detailed general index, as well as a useful geographical index.
Book Synopsis Neuse River Shad Investigations, 1953 by : Charles H. Walburg
Download or read book Neuse River Shad Investigations, 1953 written by Charles H. Walburg and published by . This book was released on 1957 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Return to the River by : Richard N. Williams
Download or read book Return to the River written by Richard N. Williams and published by Elsevier. This book was released on 2005-11-21 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Return to the River will describe a new ecosystem-based approach to the restoration of salmon and steelhead populations in the Columbia River, once one of the most productive river basins for anadromous salmonids on the west coast of North America. The approach of this work has broad applicability to all recovery efforts throughout the northern hemisphere and general applicability to fisheries and aquatic restoration efforts throughout the world. The Pacific Northwest is now embroiled in a major public policy debate over the management and restoration of Pacific salmon. The outcome of the debate has the potential to affect major segments of the region's economy - river transportation, hydroelectric production, irrigated agriculture, urban growth, commercial and sport fisheries, etc. This debate, centered as it is on the salmon in all the rivers, has created a huge demand for information. The book will be a powerful addition to that debate. - A 15 year collaboration by a diverse group of scientists working on the management and recovery of salmon, steelhead trout, and wildlife populations in the Pacific Northwest - Includes over 200 figures, with four-color throughout the book - Discusses complex issues such as habitat degradation, juvenile survival through the hydrosystem, the role of artificial production, and harvest reform
Download or read book The Progressive Fish Culturist written by and published by . This book was released on 1950 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: