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 Early Marine Distribution of Out migrating Juvenile Sockeye Salmon Oncorhynchus Nerka written by Nicole Gerbrandt and published by . This book was released on 2013 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The early marine phase is a critical period for out-migrating juvenile sockeye salmon (Oncorhynchus nerka). They undergo physiological changes while entering into a new environment, and this is thought to be a period of high mortality. This study examined factors affecting swimming depth as juveniles migrated through Rivers Inlet, and compared swimming depth at the point of ocean entry and life history strategies in sockeye salmon from Rivers Inlet and nearby populations on the Central Coast of British Columbia. Most juvenile sockeye salmon swam within two meters of the ocean's surface during their out-migration through Rivers Inlet, and were slightly deeper later in the out-migration. In addition, in a mesocosm experiment, Rivers Inlet juvenile sockeye salmon did not alter their swimming depth in response to increasing salinity at their preferred swimming depth, despite experiencing negative physiological effects when swimming in highly saline waters. Similar data on other nearby sockeye salmon populations were collected. Juvenile sockeye salmon from populations that out-migrate through brackish waters tended to be smaller than individuals from populations that leave fresh water and enter directly into highly saline marine environments, and they too tended swim within the top two to four meters of the surface. This shows that conditions in the top 4 m of the water's surface represent actual conditions experienced by out-migrating juvenile sockeye salmon in the early marine environment and is a critically important observation in terms of understanding such issues as prey availability, the potential role of brackish surface layers in coastal fjords, lagoons and estuaries, and susceptibility to predators. These findings will inform future sampling efforts on these populations, and also suggest that these populations maintain varying life history characteristics which enable them to survive early marine conditions within the top 4 m of the ocean.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2010 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecosystem Based Fisheries Management written by Jason Link and published by Cambridge University Press. This book was released on 2010-10-07 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Responsible fisheries management is of increasing interest to the scientific community, resource managers, policy makers, stakeholders and the general public. Focusing solely on managing one species of fish stock at a time has become less of a viable option in addressing the problem. Incorporating more holistic considerations into fisheries management by addressing the trade-offs among the range of issues involved, such as ecological principles, legal mandates and the interests of stakeholders, will hopefully challenge and shift the perception that doing ecosystem-based fisheries management is unfeasible. Demonstrating that EBFM is in fact feasible will have widespread impact, both in US and international waters. Using case studies, underlying philosophies and analytical approaches, this book brings together a range of interdisciplinary topics surrounding EBFM and considers these simultaneously, with an aim to provide tools for successful implementation and to further the debate on EBFM, ultimately hoping to foster enhanced living marine resource management.
Download or read book M moire concernant la province de Languedoc written by and published by . This book was released on 1698 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Review of the Research on the Early Marine Period of Pacific Salmon by Canada Japan Russia and the United States written by Philip E. K. Symons and published by . This book was released on 2003 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reports in this Bulletin summarize the studies of the early marine period of the life history of juvenile Pacific salmon. Review paper included: 1) A history of the research on the early marine life of Pacific salmon off Canada's Pacific coast; 2) Japanese studies on the early ocean life of juvenile salmon; 3) Review of Russian marine investigations of juvenile Pacific salmon; 4) Research conducted by the United States on the early ocean life of Pacific salmon.
Download or read book Factors Affecting the Production of Juvenile Sockeye Salmon Oncorhynchus Nerka in Shuswap and Quesnel Lakes British Columbia written by Canada. Department of Fisheries and Oceans and published by Cultus Lake, B.C. : Fisheries and Oceans Canada. This book was released on 1994 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Factors Affecting the Production of Juvenile Sockeye Salmon Oncorhynchus Nerka in Shuswap and Quesnel Lakes British Columbia written by J. M. B. Hume and published by . This book was released on 1994 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Comparison of the Growth Histories of Pre and Post decline Brood Years of Sockeye Salmon Oncorhynchus Nerka from Rivers Inlet Based on Otolith Analysis and in Relation to Environmental Conditions written by Claire Anne Li Loong and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The widths of growth zones recorded on otoliths of sockeye salmon (Oncorhynchus nerka) from Rivers Inlet were measured to assess the impacts of environmental conditions on growth at different life history stages. Otoliths from the pre-decline (1984-1987) and post-decline brood years (1997-2005) were compared. Post-decline juveniles were significantly larger than pre-decline individuals during the migration to sea, but grew less in the first marine year. Final size was not significantly different between time periods. Functional regression analyses were performed to investigate the relationship between otolith growth and sea surface salinity at McInnes Island. Otolith growth was positively correlated with salinity during September and October. Decreased salinity under a 30 ppt threshold appears to have signalled recent unfavourable oceanic conditions for growth and possibly survival.
Download or read book Migration of Adult Sockeye Salmon in Puget Sound and Fraser River written by Henry O'Malley and published by . This book was released on 1919 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Factors Affecting Overwinter Mortality and Early Marine Growth in the First Ocean Year of Juvenile Chinook Salmon in Quatsino Sound British Columbia written by Katherine Rose Middleton and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence suggests that the variability in recruitment of adult Pacific salmon is related to smolt survival during the first ocean year. Specifically, the first few weeks and first marine winter may be two critical periods of high mortality during early marine life. Mortality during early marine residency has been attributed to predation and size-dependent factors while high mortality during the first winter may be due to energy deficits and failure to reach a certain size by the end of the growing season. My study assessed factors influencing overwinter mortality and early marine growth in juvenile Chinook salmon (Oncorhynchus tshawytscha) from Marble River, Quatsino Sound, British Columbia. Juvenile salmon were collected during November 2005 and 2006 (fall) and March 2006 and 2007(winter). Mortality rates over the first winter derived from catch per unit effort across seasons ranged between 80-90% in all years. These are the first estimations of overwinter mortality in juvenile Pacific salmon. Fish size distributions showed no evidence of size-selective overwinter mortality between fall and winter fish in either 2005-2006 or 2006-2007. Otolith microstructure analyses showed no significant difference in circulus increment widths during the first four weeks after marine entry. Similarities in increment width indicated that early marine growth did not differ between fall and winter fish during early marine residency in 2006. These observations show that the high overwinter mortality rates of juvenile Chinook salmon in Quatsino Sound are not size-dependent. Total plankton biomass was significantly lower in the winter season but size distribution, gut fullness and energy density data did not show evidence of starvation. No correlation was found between early marine growth, size, energy accumulation and high mortality in Marble River juvenile Chinook salmon during their first ocean winter in Quatsino Sound. Possible factors influencing these high mortality rates may include non size-selective predation, disease, local environmental influences or an as yet unknown source. Future work should continue to focus on understanding the relationship between early marine survival and adult recruitment. The expansion of growth comparisons geographically and chronologically while determining the effects of predatory mortality on juvenile Chinook salmon along the north Pacific continental shelf and beyond are imperative to fully understanding this complex marine life stage.
Download or read book Summary of Fraser River Sockeye Salmon Oncorhynchus Nerka Ecology to Inform Pathogen Transfer Risk Assessments in the Discovery Islands BC written by S. C. H Grant and published by . This book was released on 2018 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SIZE AND AGE OF BRITISH COLUMBIA SOCKEYE SALMON ONCORHYNCHUS NERKA IN RELATIONS TO ENVIRONMENTAL FACTORS IN THE FISHERY written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Early Marine Growth of Juvenile Pacific Salmon in the Strait of Georgie and Soanich Inlet British Columbia written by Canada. Fisheries and Environment Canada and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sockeye Salmon Oncorhynchus Nerka written by Canada. Department of Fisheries and Oceans and published by Fisheries and Oceans, Information and Publications Branch. This book was released on 1987 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-day symposium was organized by the Department of Fisheries and Oceans and convened at Nanaimo, British Columbia in November 1985. Advice on subject matter and participation came from an external committee of senior scientists and administrators in contributing agencies in Canada, Japan, the United States, and the Union of Soviet Socialist Republics. The papers included in the proceedings deal with sockeye biology and stock management. Papers on sockeye biology are divided into those concerned primarily with life history strategies and enhancement and development. Papers dealing with management are divided into the tools of management and management of some principal stocks.
Download or read book Size and Age of British Columbia Sockeye Salmon Oncorhynchus Nerka in Relation to Environmental Factors and the Fishery written by W.E. Ricker and published by . This book was released on 1982 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EARLY MARINE GROWTH OF JUVENILE PACIFIC SALMON IN THE STRAIGHT OF GEORGIA AND SAANICH INLET BRITISH COLUMBIA written by and published by . This book was released on 1978 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
