Download or read book Biophysical Factors Associated with the Marine Growth and Survival of Auke Creek Alaska Coho Salmon Oncorhynchus Kisutch written by Joshua Benjamin Robins and published by . This book was released on 2006 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Correlation and stepwise regression analyses were used to investigate relationships between growth in four distinct marine habitats, marine survival, and biophysical indices for Auke Creek coho salmon, a coho salmon population in Southeast Alaska. Early marine growth of males and females were positively correlated, but neither was correlated with early marine growth of jacks. Regional biophysical indices had significant effects on early marine growth of jack, but not on early marine growth of adult coho salmon. Sea surface temperature and number of hatchery pink and churn salmon juveniles released had negative and positive effects on growth in strait habitat, respectively. Hatchery pink and churn salmon abundance and pink salmon catch in Northern Southeast Alaska were negatively related to the growth of Auke Creek coho salmon in the late ocean phase. The average length-at-return of males, but not females, was negatively related to the abundance of hatchery pink and chum salmon. Female and male size-at-return were positively correlated (r = 0.68) but within-year variation was less for females, indicating possible sex-specific differences in adult size requirements associated with reproductive success. Adult survival and jack return rate were significantly related to early marine growth of adults and jacks, respectively, indicating size-selective mortality. Hatchery pink and churn salmon abundance had positive effects on adult survival and jack return rate"--Leaf iii.
Download or read book Factors Affecting Marine Growth and Survival of Auke Creek Alaska Coho Salmon Oncorhynchus Kisutch written by Ryan Jordan Briscoe and published by . This book was released on 2004 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Correlation analyses and stepwise regression models were run to examine relationships between Auke Creek coho salmon marine survival, scale growth, and a number of physical and biological covariates: local sea surface and air temperatures, local precipitation, the Pacific Decadal Oscillation, local hatchery release numbers, size at return, and regional and state salmon catch numbers. Jack survival and adult survival covaried strongly, suggesting the primary cause of mortality is encountered in the first four or five months of marine life. The number of hatchery fish had the strongest correlation with marine survival (r = 0.71), which could indicate that hatchery releases are prey for Auke Creek coho smolts or buffering these smolts from predators. Sea surface temperature was not significantly associated with adult survival, but was with jack survival. Surprisingly, scale growth was not correlated with marine survival. Adult size appears to be determined in the last year of marine life when the fish are in the Gulf of Alaska. Regional survival trends followed closely with Auke Creek marine survival, indicating factors affecting survival are regional in scope. Specific mechanisms were not defined, but the results indicate biological covariates were more associated with Auke Creek coho survival than were physical covariates"--Leaf iii.
Download or read book Evaluation of Marine and Freshwater Growth and Survival of Auke Creek Coho Salmon written by Joshua R. Russell and published by . This book was released on 2019 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coho Salmon (Oncorhynchus kisutch) are a species of great social and economic importance for commercial, sport, personal-use, and traditional harvest. We explored factors influencing Auke Creek Coho Salmon smolt production, growth, and marine survival. We analyzed 35 years (1980-2014) of data collected at the Auke Creek Research Station weir in Juneau, Alaska. This extensive data series allowed for an analysis of Auke Creek Coho Salmon growth and survival that is not possible elsewhere. Creek flow best explained variation in smolt-per-adult production. Analysis of freshwater and saltwater scale growth zones failed to identify a specific growth zone with a significant influence on marine survival. Marine survival had a positive relationship with the magnitude of regional hatchery releases and the Pacific Decadal Oscillation. Changes in climate and hatchery production could have negative effects on survival of Auke Creek Coho Salmon, as evidenced by low returns in recent years associated with anomalously high temperatures in the Gulf of Alaska. The impact of climate change and increased hatchery production should be considered in future management decisions.
Download or read book Effects of Smolt Length and Emigration Timing on Marine Survival and Age at Maturity of Wild Coho Salmon Oncorhynchus Kisutch at Auke Creek Juneau Alaska written by Judith Lynn Lum and published by . This book was released on 2003 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Coho salmon Oncorhynchus kisutch smolt were collected during the 1993-1997 emigrations at Auke Creek near Juneau, Alaska. Each day emigrants were separated into four size categories: small 90 mm), medium (90 - 110 mm), large (111 - 125 mm), and extra large ( 125 mm), tagged with a sequentially coded-wire tag, and released at tidewater. Tags from returning adults and jacks were collected and decoded in 1993-1998. Most survivors originated from the large and extra large categories, 40.5% and 43.1%, respectively. Large smolts contributed 28.9% to smolt-to-jack returns, significantly less than the smolt-to-jack survival contributed by extra large smolts, 67.8%. Smolt year, emigration date, and smolt length were significant in determining the length of returning jacks. In the 1993 and 1997 smolt years, significantly smaller returning adults originated from smolts that migrated later. Larger smolts produced significantly larger returning adults in all smolt years except 1994"--Leaf iii.
Download or read book Factors Affecting Growth and Survival of Coho Salmon Oncorhynchus Kisutch and Chinook Salmon O Tshawytscha in Saltwater Net pens in Puget Sound written by Conrad V. W. Mahnken and published by . This book was released on 1978 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Biological and Genetic Factors Influencing Local Adaptation of Pink Salmon Oncorhynchus Gorbuscha in Auke Creek Alaska written by Christopher V. Manhard and published by . This book was released on 2016 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific salmon form distinct, locally adapted populations because of the spatial and temporal precision with which they home to their natal streams. Local adaptation is recognized as an important component underlying the productivity and sustainability of salmonid populations, yet there remains uncertainty of the scale at which it occurs. This uncertainty was addressed by analysis of demographic, genetic, and experimental data collected from seasonally structured brood lines of Pink Salmon that spawn in Auke Creek, Alaska. An extensive background of research on this system has indicated that the timing of the adult and juvenile migrations is closely aligned with fitness and productivity in this stream; this background provided a framework for synthesizing the results of the analyses to address these questions: (1) What ecological factors influence productivity of the freshwater and marine life history stages; (2) Do these factors suggest a mechanism for evolution of migration time; (3) What are the consequences of disrupting fine-scale local adaptation of migration time? Freshwater productivity appeared to be influenced primarily by competition for spawning habitat, rather than variability in environmental conditions. Marine productivity, conversely, was associated with physical processes that influence survival of juveniles in the nearshore environment. Consistent with these findings, genetic evolution of earlier migration time, which was observed in both adults and juveniles over two generations, appeared to be driven by earlier vernal warming of the nearshore environment. Despite these environmental changes and resulting selection against late migrating fish, recruitment to Auke Creek has remained stable, thereby indicating that seasonal structure of migration time has supported sustained productivity in a changing climate. Experimental relaxation of natural barriers to gene flow that maintain the seasonal structure resulted in intermediate adult migration times in two generations of hybrid fish. These patterns were consistent with an additive genetic basis for migration time and suggest that ecological outbreeding depression is a post-zygotic mechanism that maintains adaptive variation of migration time in Auke Creek. Collectively, these results provide evidence that fine-scale local adaptation can enhance productivity of salmonid populations while providing resilience to climate change.
Download or read book Variable Effects of Biological and Environmental Processes on Coho Salmon Marine Survival in Southeast Alaska written by Michael J. Malick and published by . This book was released on 2008 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: "I examined the relationships between coho salmon Oncorhynchus kisutch marine survival and seven biological and physical covariates across 14 Southeast Alaska (SEAK) stocks. A primary focus of the study was to investigate the influence of pink O. gorbuscha and chum O. keta salmon fry abundances on marine survival. The coho salmon stocks exhibited strong covariation, suggesting common regional processes are influencing marine survival in SEAK. However, only two of the covariates, the North Pacific index and SEAK pink salmon harvest, had consistent relationships across all 14 stocks with both of the covariates relating positively with marine survival. The other covariates all had inconsistent relationships with marine survival. An index representing hatchery pink and chum salmon fry abundance had a stronger estimated effect on marine survival than an index of wild pink salmon fry abundance and SEAK pink salmon harvest numbers. The magnitude and sign of the hatchery pink and chum salmon effect varied greatly among different localities. This study provides evidence that coho salmon stocks throughout SEAK experience some degree of regional concordance in the marine environment, but also that local stock specific conditions are important in fully understanding variation in marine survival"--Leaf iii.
Download or read book Challenges for Diadromous Fishes in a Dynamic Global Environment written by Alex Haro and published by . This book was released on 2009 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sponsored by the Northeastern Division, American Fisheries Society.
Download or read book Behavior and Survival of Coho Salmon Oncorhynchus Kisutch Walbaum in Sashin Creek Southeastern Alaska written by Richard Allan Crone and published by . This book was released on 1968 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Behavior and survival in fresh water were studied for three brood years of coho salmon in Sashin Creek, Alaska, from October 1963, until September 1966. Investigations of spawning adults were conducted to determine numbers of spawners, distribution on the spawning grounds, effects on pink salmon, age composition, redd life, fecundities, and egg retention. Juvenile coho were studied to determine changes in population size, distribution in the stream, age composition of the population, food habits, and rates of mortality during fresh-water life. The number of coho spawners counted into Sashin Creek each year normally varied from 50 to 300. Weir counts and estimations of the number of spawners determined from observed spawning effort and redd life were not accurate methods of estimating the coho escapement into Sashin Creek. In 1965, a more accurate estimate was obtained by tagging a portion of the run and recording marked to unmarked ratios on the spawning grounds. I estimated that less than two percent of the viable pink salmon embryos were destroyed in 1965 by the spawning activities of coho salmon. Most coho spawners returned to Sashin Creek in 1965 and 1966 in their fourth year of life after having migrated to sea in their third year (designated 43). Smaller numbers of 32 and 54 individuals composed the remainder of the spawning population. The mean redd life of 56 females was 13 days. A small sample of coho from Sashin Creek examined for fecundity in 1966 gave a mean of 2,868 eggs per female. A weir or fyke net was fished in the spring to estimate emigration of juvenile coho. Coho smolts left Sashin Creek from April through July; peak emigration occurred in late May or early June. Coho fry left the stream in the spring and summer in widely varying numbers from year to year. I estimated from growth data, population estimates, and analysis of scale samples that most coho juveniles remained in Sashin Creek for two growing seasons before migrating to sea. Analysis of scales from juvenile coho indicated that some reabsorption of scales occurs during the winter. The possibility of reabsorption of circuli makes back-calculation of the length of younger age-groups of coho from scale measurements unreliable. Diptera were represented more often than any other order of insects in the stomachs of juvenile coho. Hemiptera were important as food items to juvenile coho in a tributary stream. The estimated survival from egg deposition to immediately prior to emergence varied between 17.5 and. 34.9 percent for the three brood years, and averaged 27. 8 percent. Early summer populations of fry were variable in size and dependent on the size of the egg deposition of the brood. Populations of fry declined rapidly during July and early August. Instantaneous mortality rates were much higher for this period than during any other time in the fresh-water life of coho salmon in Sashin Creek. Mortality dropped to a low level during the following winter period.
Download or read book Effects of Logging on Growth of Juvenile Coho Salmon written by Paul M. Iwanaga and published by . This book was released on 1973 with total page 52 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 Analysis of Factors Potentially Inflating the Marine Survival Estimate of Coho Salmon oncorhynchus Kisutch at Mill Creek Yaquina River Central Oregon Coast written by James Ray and published by . This book was released on 2006 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of copper and zinc on smoltification of coho salmon written by Harold W. Lorz and published by . This book was released on 1977 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Survival of Coho Salmon Oncorhynchus Kisutch in Washington State written by Jessica L. Beetz and published by . This book was released on 2009 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic and Environmental Effects on Developmental Timing Otolith Formation and Gill Raker Development in Pink Salmon from Auke Creek Alaska written by Dion Oxman and published by . This book was released on 2012 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: To determine how inheritance, environment, and hybridization influenced developmental timing, otolith formation, and gill raker development in pink salmon (Oncorhynchus oorbuscha), full and half-sibling families from Auke Creek, Alaska and third generation outbred hybrids between Auke Creek females and Pillar Creek males from Kodiak Island, Alaska (1,000 km distant) were incubated in ambient, chilled, and warmed water. Variation in development time of embryos from the odd-year broodline was primarily influenced by additive genetic factors, whereas no genetic effect was detected in the even-year run. No genotype-by environment (GxE) effects were associated with sires or families in either broodline, indicating that the observed variation in development time was likely the result of phenotypic plasticity. Hybridization (outbreeding) significantly prolonged development time in both broodlines, indicating that the phenotypic effects of outbreeding can last at least three generations. Early otolith development was genetically conserved and canalized, but the phenotypic expression of these genes is plastic and strongly influenced by environmental factors. There was no evidence that local adaptation or outbreeding influenced otolith morphology or shape. Otoliths from fish exposed to thermal stress were bilaterally asymmetrical, whereas the bilateral symmetry of otoliths from outbred fish exhibited evidence of heterosis because they were more symmetrical than their native counterparts. Unlike development time and otoliths, gill raker development was linear and consistently stable in the face of both hybridization and environmental stress. These results make it clear that different biological attributes respond to genetic control and stress in different ways.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 1988 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Chum Salmon in Relation to Population Abundance and Climate in the Eastern North Pacific Ocean and the Recruitment of Pollock in the Eastern Bering Sea written by Ellen Martinson Yasumiishi and published by . This book was released on 2013 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global climate change is expected to change the distribution and growth of marine species. Therefore, understanding how climate, ocean productivity, and population abundance affect the dynamics of marine species will help predict how growth and recruitment of marine species will respond to future changes in climatic and oceanic conditions. Statistically significant intertemporal correlations have been observed between a variety of environmental factors and recruitment, growth, mortality, and abundance of fish populations. However, because these correlative relationships are not reflective of the actual biophysical processes, the relationships can break down, particularly when used for forecasting. Failure of these simple correlative relationships motivates the search for biological indicators that integrate ocean productivity across ecological dimensions and through time. Measured distances along Chum Salmon (Oncorhynchus keta) scale radii and associated body morphology were used to construct time series of Chum Salmon growth and, by extension, time series of productivity of those ecological domains salmon have exploited. Seasonal and annual marine growth of Chum Salmon from Fish Creek, Alaska and Quilcene River, Washington were examined in relation to population abundances and climate indices, 1972-2004. Final body size at maturity of these Chum Salmon was associated with variation in immature growth incurred while in oceanic waters. Density-dependent effects and climate explained some of the variation in growth but did not account for the entire increase in size at maturity in the mid-1990s. In the Bering Sea, Chum Salmon growth was assessed as an indicator for the recruitment of Walleye Pollock (Theragra chalcogramma) to age-1 in an effort to support an ecosystem-based fisheries management. Chum Salmon growth and the maximum of the monthly sea surface temperature explained 85% of the variation in age-1 Walleye Pollock recruitment. Higher Walleye Pollock recruitment success was associated with the combined effect of a cool late summer and intermediate growth of Chum Salmon. The combination of a physical and biological indicator served as the best indicators for changes in the marine growth of Chum Salmon and for the recruitment of Walleye Pollock.
