Download or read book Factors During Early Marine Life that Affect Smolt to adult Survival of Ocean type Puget Sound Chinook Salmon Oncorhynchus Tshawytscha written by Elisabeth J. Duffy and published by . This book was released on 2009 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Size selective Mortality and Environmental Factors Affecting Early Marine Growth During Early Marine Life Stages of Sub yearling Chinook Salmon in Puget Sound Washington written by Madilyn Marisa Gamble and published by . This book was released on 2016 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Body size, mediated through biotic and abiotic factors affecting growth, is fundamental in determining survival as larger animals are usually less vulnerable to predation, starvation, and extreme environmental conditions (Peterson & Wroblewski 1984; Sogard 1997). Size-selective mortality is a prevalent force regulating marine survival for many anadromous salmonid species, including ESA-listed Chinook salmon (Oncorhynchus tshawytscha) in Puget Sound, WA. The “critical size – critical period” hypothesis suggests that marine survival of anadromous Pacific Salmon (Oncorhynchus spp.) is controlled by two size-selective survival bottlenecks – one during the first marine summer and another during the first marine winter (Beamish and Mahnken 2001). Previous research has indicated a strong positive relationship between the size of juvenile ESA-listed Chinook salmon (O. tshawytscha) in Puget Sound and their survival to adulthood, indicating that early marine growth drives survival (Duffy 2009). Before investigating the drivers of early marine growth, however, it is imperative to understand whether size-selective mortality occurs prior to July in Puget Sound. If so, we may be able to augment marine survival by directing conservation and restoration efforts toward the habitats or regions of Puget Sound where size-selective mortality occurs. Additionally, we must account for any size-selective mortality in estimating early marine growth, as observed weight in July would reflect an artificially inflated “apparent” growth if smaller individuals were experiencing disproportionately high mortality. In this study, we repeatedly sampled nine stocks of both wild and hatchery-origin sub-yearling Chinook salmon during their outmigration into and rearing in Puget Sound. We used scale morphometrics to determine if size-selective mortality is affecting sub-yearling Chinook salmon during their first marine summer rearing in Puget Sound, and if so, where and when that size-selective mortality occurs. We found no evidence of size-selective mortality occurring between habitats or between sampling periods within habitats, suggesting that weight of juvenile Chinook as measured in July is representative of early marine growth and that size-selective mortality occurs later in the summer or outside Puget Sound during the first marine winter. We then focused on understanding differences in growth rates across time, among habitats, and among stocks of juvenile Chinook salmon, and used bioenergetic models to determine the relative influence of prey quality, prey availability, and temperature on early marine growth rates We found that sub-yearling Chinook were larger and grew faster in offshore than in nearshore habitats, and that this difference in growth rate was likely due to differences in prey availability and may have been exacerbated by higher nearshore temperatures. The results of this study can be used to direct restoration and conservation efforts aimed at supporting early marine growth of juvenile Chinook in Puget Sound, and can augment our understanding of distribution patterns and feeding behaviors of Pacific salmon during critical growth periods.
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 Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2014 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Upstream written by National Research Council and published by National Academies Press. This book was released on 1996-07-17 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of salmon to the Pacific Northwestâ€"economic, recreational, symbolicâ€"is enormous. Generations ago, salmon were abundant from central California through Idaho, Oregon, and Washington to British Columbia and Alaska. Now they have disappeared from about 40 percent of their historical range. The decline in salmon numbers has been lamented for at least 100 years, but the issue has become more widespread and acute recently. The Endangered Species Act has been invoked, federal laws have been passed, and lawsuits have been filed. More than $1 billion has been spent to improve salmon runsâ€"and still the populations decline. In this new volume a committee with diverse expertise explores the complications and conflicts surrounding the salmon problemâ€"starting with available data on the status of salmon populations and an illustrative case study from Washington state's Willapa Bay. The book offers specific recommendations for salmon rehabilitation that take into account the key role played by genetic variability in salmon survival and the urgent need for habitat protection and management of fishing. The committee presents a comprehensive discussion of the salmon problem, with a wealth of informative graphs and charts and the right amount of historical perspective to clarify today's issues, including: Salmon biology and geographyâ€"their life's journey from fresh waters to the sea and back again to spawn, and their interaction with ecosystems along the way. The impacts of human activitiesâ€"grazing, damming, timber, agriculture, and population and economic growth. Included is a case study of Washington state's Elwha River dam removal project. Values, attitudes, and the conflicting desires for short-term economic gain and long-term environmental health. The committee traces the roots of the salmon problem to the extractive philosophy characterizing management of land and water in the West. The impact of hatcheries, which were introduced to build fish stocks but which have actually harmed the genetic variability that wild stocks need to survive. This book offers something for everyone with an interest in the salmon issueâ€"policymakers and regulators in the United States and Canada; environmental scientists; environmental advocates; natural resource managers; commercial, tribal, and recreational fishers; and concerned residents of the Pacific Northwest.
Download or read book Alaska Fishery Research Bulletin written by and published by . This book was released on 1994 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Early Marine Migratory Patterns and the Factors that Promote Resident Type Behavior of Chinook Salmon Oncorhynchus Tshawytscha in Puget Sound Washington written by Joshua Chamberlin and published by . This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology of Atlantic Salmon and Brown Trout written by Bror Jonsson and published by Springer Science & Business Media. This book was released on 2011-05-03 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.
Download or read book Growth and Degree of Maturity of Chinook Salmon in the Ocean written by Willis Horton Rich and published by . This book was released on 1925 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aspects of Growth and the Effects of Some Environmental Factors on Pen reared Chinook Salmon Oncorhynchus Tshawytscha Walbaum in Puget Sound Washington written by John Richard Moring and published by . This book was released on 1975 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Marine Environment on Age and Size at Maturity Growth and Abundance of Chum Salmon Ohcorhynchus Keta Walbaum from Olsen Creek Prince William Sound Alaska written by John H. Helle and published by . This book was released on 1979 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of the marine environment on age and size at maturity, early marine growth, and abundance of chum salmon, Oncorhynchus keta, were studied at Olsen Creek during 1959-77. Chum salmon returned to Olsen Creek as predominately 3-, 4-, and 5-year fish; however, age composition varied from year to year. The mean age composition for the brood years 1956-72 for males was 15%, 66%, and 19% for 3-, 4-, and 5-year fish, respectively. Mean age composition for females of the same broods showed slightly higher percentages of older fish: 9%, 67%, and 23% for 3-, 4-, and 5-year fish, respectively. Some 6-year chum salmon returned to Olsen Creek between 1968 and 1975; but, only in 1973 did the number of 6-year fish (3%) represent more than 1% of the returns. Population sizes tended to be larger during these years, and mean age increased as the number of fish in a brood increased. Intraseasonally, age of new chum salmon spawners at Olsen Creek decreased as the season progressed. Mean size of older spawners was greater than the mean size of younger spawners; but, the ranges in size of the three age groups overlap each other so size is not a good criterion for estimating age of chum salmon. Measurement of circuli and distances on adult scales were used to estimate growth of chum salmon during their first two years of marine life. Both number of circuli and distances on scales of juvenile chum salmon after their first summer in Prince William Sound were shown to be related to length of the fish. Growth during the first season at sea was not related to age at maturity; however, amount of growth acquired during the second marine season was negatively related to age at maturity. Growth during the first summer at sea was related to sea surface temperatures and marine weather parameters in Prince William Sound and in the northern Gulf of Alaska. Location of chum salmon from Olsen Creek during their second year at sea is unknown. Fluctuations in size (length) at maturity were more similar between fish from different broods returning during the same year than they were for fish that matured at different ages from the same broods. Length at maturity was related to marine weather factors during their last summer at sea in the northern Gulf of Alaska and Prince William Sound. Length at maturity was also related to mean summer sea surface temperature in Prince William Sound during the year of return. Total survival of each brood was estimated from the ratio of number of progeny (returns) to number of parents (spawners). No direct relationships were found between survival and growth during the first or second season in the sea, sea surface temperatures, or upwelling indices along the coast. However, a highly significant relationship was found between the survival of progeny and mean length of the parents.
Download or read book Synopsis of Biological Data on the Chum Salmon Oncorhynchus Keta Walbaum 1792 written by Richard G. Bakkala and published by . This book was released on 1970 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Impacts on Pacific Salmon written by Richard James Beamish and published by . This book was released on 2010 with total page 176 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 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 Physiological Ecology of Pacific Salmon written by Cornelis Groot and published by UBC Press. This book was released on 2010-10-01 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every year, countless juvenile Pacific salmon leave streams and rivers on their migration to feeding grounds in the North Pacific Ocean and the Bering Sea. After periods ranging from a few months to several years, adult salmon enter rivers along the coasts of Asia and North America to spawn and complete their life cycle. Within this general outline, various life history patterns, both among and within species, involve diverse ways of exploiting freshwater, estuarine, and marine habitats. There are seven species of Pacific salmon. Five (coho, chinook chum, pink, and sockeye) occur in both North America and Asia. Their complex life histories and spectacular migrations have long fascinated biologists and amateurs alike. Physiological Ecology of Pacific Salmon provides comprehensive reviews by leading researchers of the physiological adaptations that allow Pacific Salmon to sustain themselves in the diverse environments in which they live. It begins with an analysis of energy expenditure and continues with reviews of locomotion, growth, feeding, and nutrition. Subsequent chapters deal with osmotic adjustments enabling the passage between fresh and salt water, nitrogen excretion and regulation of acid-base balance, circulation and gas transfer, and finally, responses to stress. This thorough and authoritative volume will be a valuable reference for students and researchers of biology and fisheries science as they seek to understand the environmental requirements for the perpetuation of these unique and valuable species.
Download or read book Factors Affecting the Saltwater entry Behavior and Saltwater Preference of Juvenile Chinook Salmon Oncorhynchus Tshawytscha written by Carol Seals Price and published by . This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: From 1998-2000, laboratory studies were conducted to examine factors that impact saltwater-entry behavior and saltwater preference (SWP) of juvenile chinook salmon, Oncorhynchus tshawytscha. These factors included bacterial kidney disease, stress and the presence of trout, O. mykiss. An additional study investigated the orientation of the startle response of chinook salmon within a salinity gradient. All experiments were conducted in 757-1 tanks in which a stable, vertical salinity gradient was established. SWP was decreased in fish suffering from bacterial kidney disease (31 ± 20.0%), compared with control fish (85 ± 17.6%). A mild chasing stressor resulted in a 26% decrease in SWP relative to unstressed fish. After a severe handling stressor, only 20% of fish preferred salt water, compared with 100% of unstressed controls. After exposure to an overhead predator model, severely stressed fish descended into the saltwater layer, but this response was transient. The presence of non-aggressive steelhead trout did not affect SWP of chinook salmon. Chinook salmon stocked with rainbow trout displayed decreased SWP. Aggression levels in tanks with rainbow trout were higher than in tanks with only chinook salmon. The orientation of the startle response was affected by the presence of salt water. Fish that preferred salt water within a gradient responded by moving horizontally within the saltwater layer. In contrast, control fish (held only in freshwater) moved vertically within the water colunm when startled. Prior preference for salt water superseded the inclination to move upward in the water column when startled. Smoltification involves physiological, behavioral and morphological changes that prepare healthy chinook salmon for seawater residence. However, disease, stress and aggressive interactions can decrease the SWP of fish at this life history stage. Avoidance of salt water during estuarine outmigration is likely maladaptive, and may have ecological ramifications including increased risk of avian predation during outmigration and decreased fitness in the marine environment.
