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Author : Rick Andrew Elsner
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (124 download)
Download or read book Smolt Development in Distinct Populations of Coho Salmon (oncorhynchus Kiutch) written by Rick Andrew Elsner and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 124 pages
Book Rating : 4.:/5 (11 download)
Download or read book A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (Oncorhynchus Kisutch) Movement Timing and Growth Patterns Prior to Ocean Entry written by and published by . This book was released on 2016 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may growth and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations.
Author : Sean M. Cochran
Publisher :
ISBN 13 :
Total Pages : 110 pages
Book Rating : 4.:/5 (961 download)
Download or read book Marine Survival of Coho Salmon (Oncorhynchus Kisutch) from Small Coastal Watersheds in Northern California written by Sean M. Cochran and published by . This book was released on 2015 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: California coho salmon Oncorhynchus kisutch populations are at low abundance and factors governing recruitment variability remain unclear. Changes in freshwater habitat that increase juvenile growth and size of salmon outmigrating to sea (smolts) may improve ocean survival. The best data to evaluate this among wild coho salmon populations in California come from life-cycle monitoring (LCM) stations. This study investigated whether marine survival is size-dependent (larger individuals within a cohort have higher marine survival) and whether sites and years with higher growth have higher marine survival across five LCM locations. I tested for size-dependent survival using two techniques: comparing the size of outmigrating smolts and back-calculated smolt sizes from scales of adult fish that survived to return; and using information from fish that were tagged as smolts and survived to return as adults. Analyses comparing smolt sizes back-calculated from adult scales and observed lengths from smolt traps indicated that within-year size-dependent mortality at sea occurred among many outmigrant cohorts, while analyses using smolt lengths of recaptured adult fish tagged as juveniles did not indicate any within-cohort size-selective mortality at sea. Potential explanations for the conflicting results include errors in scale back-calculation; smolts growing in habitats below smolt traps prior to ocean entrance; and fish with alternative juvenile life histories that were unaccounted for in outmigrant sampling surviving and contributing to the adult populations. In regressions across sites and years, marine survival was positively associated with early marine growth measured from the scales of surviving adult salmon and in some instances marine survival was also positively associated with mean fork length of outmigrating smolts. Although size may be an important determinant of ocean survival, this study shows that comparison of back-calculated smolts sizes from scales of adult fish and observed lengths of smolts at an upstream trapping location are unreliable approaches for testing size-selective mortality. This study also provides support for expanding studies at LCM stations to determine how juvenile coho salmon use habitat downstream of migrant trapping locations.
Author : Betsy W. McCracken
Publisher :
ISBN 13 :
Total Pages : 212 pages
Book Rating : 4.:/5 (128 download)
Download or read book Spawning Site Selection of Coho Salmon Oncorhynchus Kisutch in Susitna River Tributaries, Alaska written by Betsy W. McCracken and published by . This book was released on 2021 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coho Salmon Oncorhynchus kisutch are the most widely distributed Pacific salmon species across Alaska. The lack of knowledge surrounding the habitat requirements of this species results in challenges for conservation and management due to natural and anthropogenic pressures. Tributaries of the Susitna River drainage in Alaska support many small and distinct Coho Salmon populations. Heterogeneity of in-stream spawning habitat is an ecological concept known to promote resiliency of salmonid populations. The goal of this study was to investigate the best habitat predictors of spawning site selection and the scale by which spawning habitat should be evaluated for management insights. Scale is particularly important when measuring, assessing, and predicting potential impacts to species from development activities because habitat research at the stream rather than the reach scale can overestimate the amount of available spawning habitat. I investigated a suite of field-measured stream habitat variables paired with empirical Coho Salmon spawning survey data in five tributaries during 2013 and 2014. Physical data was defined as biotic and abiotic surroundings of an organism or population that have an influence on survival, development, and evolution. Mixed-effects modeling results indicated that Coho Salmon spawning-site selection was positively related to gravel substrate and the presence of groundwater flux, and that spawning Coho Salmon avoided cobble substrate. Physical data were analyzed at both the stream and reach scales, and mixed-effects modeling results further concluded that variation in spawning activity at the reach scale (variance = 1.34, SD = 1.16) accounted for more variability and was more predictive than at the stream scale(variance = 0.04, SD = 0.19). This is important because fish habitat-associations identified at the reach scale were not identified at the stream scale. These results highlight the need for multi-scale habitat data collections and analyses to identify the most meaningful fish-habitat associations.
Author : Harold W. Lorz
Publisher :
ISBN 13 :
Total Pages : 100 pages
Book Rating : 4.:/5 (318 download)
Download or read book Effects of Several Metals on Smolting of Coho Salmon written by Harold W. Lorz and published by . This book was released on 1978 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Hugrún Gunnarsdóttir
Publisher :
ISBN 13 :
Total Pages : 144 pages
Book Rating : 4.:/5 (31 download)
Download or read book Scale Patterns Indicate Changes in Use of Rearing Habitat by Juvenile Coho Salmon, Oncorhynchus Kisutch, from 1955 to 1984 in the Tenmile Lakes, Oregon written by Hugrún Gunnarsdóttir and published by . This book was released on 1992 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was designed to provide information about the juvenile life history of coho salmon, Oncorhynchus kisutch, in the Tenmile Lakes in Oregon by 1) classifying scales of spawning fish and outgoing smolts (1+), 2) assessing the contribution of juvenile life history types to the returns of adults (32) and jacks (22), and 3) comparing growth rates and survival of different types. Scales of outmigrating smolts from one brood year, jacks from two brood years, and scales of adults from four brood years were classified into juvenile life histories and examined for several scale characters. A linear discriminant function analysis was used to show the separation of the types and to determine the most distinguishing scale characters. Length of smolts at ocean entry back-calculated from scales of jacks and adults was compared with the length of the observed group of emigrating smolts. Based on variation in numbers and spacing of circuli and the size of the freshwater scale zone, believed to represent different residence time in the tributaries and the lakes, four types of juvenile life histories were defined. Fish classified as type 1, stream-reared, are believed to have reared in the tributaries until migrating as smolts in the following year. Type 2, stream-lake-reared, fish are thought to have reared in the tributaries for almost a year but then moved down to the lakes, where rearing continued until smolt migration in spring. Type 3, stream-lake- reared, are believed to have reared for a short time in the tributaries, then moved down to the lakes sometime in their first year of life. Rearing continued in the lakes until spring of the following year. Type 4, lake-reared, are thought to have moved down to the lakes shortly after emergence from the gravel, where they reared until migrating as smolts in the following spring. Scales of smolts, jacks, and adults were sorted into these four types. Presently, coho salmon fry and yearlings appear to be moving out of tributaries in late spring and from March to beginning of May, respectively. Migration of smolts out of the lake system to the ocean occurs mostly within the month of May. Recent habitat surveys show that dramatic seasonal changes occur in use of rearing habitat by juvenile coho salmon in the Tenmile Lakes tributaries from summer to winter. In winter juveniles appear to be using more low gradient, low velocity, off-channel areas than in summer. Fish of type 4 represented 90%, 43%, and 74% of the returns of adults in 1957- 58, 1963-64, and 1971-72, respectively, and 90% of the returns of jacks in 1962-63 and 1970-71. However, no type 4 fish was represented in the returns of adults in 1985-86, whereas type 1 fish represented 89% of the returns. Type 4 appeared to have grown better in fresh water, reached a larger size at outmigration, and have a greater relative survival than fish of type 2, when compared among the observed group of smolts, returning jacks, and adults. The large proportion of the escapement returning as jacks for some of the years may indicate good growing condition for juvenile coho salmon in fresh water. According to the classification of jack scales a large proportion of fish returning as jacks were lake-reared and were found to be larger at migration to ocean than fish returning as adults. This may suggest that fish that reared well in the lakes and reached a large size at outmigration had the tendency to mature early and return as jacks. Based on the analysis of scales, lake-reared juvenile coho salmon formerly contributed well to adult returns. The former high returns of jacks and adults reflect the importance of the lake habitat for the coho salmon populations of this system. In order to enhance this stock to a higher level, management strategies should be focused on making the lake habitat available to juvenile coho salmon for at least some part of their freshwater life.
Author :
Publisher :
ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.3/5 (121 download)
Download or read book Endangered and Threatened Species ; Threatened Status for Southern Oregon/Northern California Coast Evolutionarily Significant Unit (ESU) of Coho Salmon written by and published by . This book was released on 1997 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Gordon H. Reeves
Publisher :
ISBN 13 :
Total Pages : 24 pages
Book Rating : 4.:/5 (319 download)
Download or read book Identification of Physical Habitats Limiting the Production of Coho Salmon in Western Oregon and Washington written by Gordon H. Reeves and published by . This book was released on 1989 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Alexander Mitchell Espy Schreiber
Publisher :
ISBN 13 :
Total Pages : 192 pages
Book Rating : 4.:/5 (313 download)
Download or read book The Influence of Environmental Salinity and Growth Hormone on Coho Salmon (Oncorhynchus Kisutch (Walbaum)) Osmoregulatory Physiology written by Alexander Mitchell Espy Schreiber and published by . This book was released on 1994 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Salmon migrating from freshwater (FW) to saltwater (SW) must maintain a constant internal osmotic environment to survive their external salinity transition. Up to 40% of SW introduced coho become stunted and eventually die. With the exceptions of growth hormone (GH), hypocalcin, and possibly epinephrine, stunts maintain a hypoendocrine status. Nine hundred yearling coho salmon were raised in SW for five months; 100 salmon were reared in FW for the same duration. After five months in SW 12% of the population developed into stunts as defined morphologically by low body weight and the retention of parr marks. Early stunts hypoosmoregulated more effectively than their smelt counterparts (significantly higher gill chloride cell activity, higher mean intestinal water/ion transport, significantly lower blood osmotic pressures), but over a period of several days displayed fatal osmoregulatory failure (significantly decreased gill chloride cell activity, decreased mean intestinal water/ion transport, significantly increased blood osmotic pressures). Increased liver potassium in stunts correlated positively with blood osmotic pressure and may be a causal agent of osmoregulatory dysfunction. Elevated liver potassium was found to be a probable function of stress (possibly epinephrine mediated), but not of blood osmotic pressure. Muscle potassium concentrations appear to be a direct function of the protein to fat ratio in the muscle, with healthy smelts possessing low muscle K+ and stunts higher muscle K+. Stunt muscle K+ was not influenced by elevated blood osmotic pressure. Fish allowed to smelt in FW (after four months) appear to revert back to the physiological form of a parr. Coho which smoltified in SW, and were then reacclimated to FW for one month retained elevated intestinal water transport rates (J[subscript v]) characteristic of a SW fish, but otherwise resembled the FW reared smelts. After FW reacclimation and hormone level normalization, stunts and smelts were exposed to 67% SW for 12 hours. During this time stunts maintained lower blood osmotic pressures than the smelts; this can be attributed to a reduced stunt intestinal J[subscript v] which was lacking in the smelts. Salmon growth hormone (sGH) injected intramuscularly for three weeks increased gill chloride cell activity, reduced blood osmotic pressure, and raised mean intestinal J[subscript v] rates in stunts and smelts placed in 67% SW for 12 hours. These characteristics resemble early SW stunt physiology, and thus may help implicate naturally increased GH in SW stunts as an osmoregulatory crutch to an otherwise hypoendocrine condition. Finally, after studying the relationship of fish size to migratory behavior within several different species, it seems that stunt distributions could potentially divide certain species with moderate degrees of anadromy into separate migratory and non-migratory populations. Considering the high amount of energy required to sustain anadromous behavior, a more efficient non- migratory population could be selected for (given adequate food availability). Viewed in this way stunts might be considered a population in transition to full FW residency, rather than just fish with a hypoosmoregulatory dysfunction"--Document.
Author : Harold W. Lorz
Publisher :
ISBN 13 :
Total Pages : 92 pages
Book Rating : 4.3/5 (91 download)
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 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Production of All-female Populations of Coho Salmon, Oncorhynchus Kisutch, Using Y-chromosomal DNA Markers written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : David Wah Kwai Au
Publisher :
ISBN 13 :
Total Pages : 490 pages
Book Rating : 4.:/5 (817 download)
Download or read book Population Dynamics of the Coho Salmon and Its Response to Logging in Three Coastal Streams written by David Wah Kwai Au and published by . This book was released on 1972 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines the ecology and dynamics of coho salmon (Oncorhynchus kisutch) in environments experimentally altered by logging. The objective was to evaluate processes that stabilize or regulate the populations. Two small watersheds in Oregon's Coast Range were logged in 1966, one clear-cut, the other patch-cut. A third adjacent watershed was left uncut as a control. The influence of these treatments on the biology of the coho was assessed. Attention was concentrated on populations of the six year classes 1963 to 1968. The natural variability of streamflow-related conditions influencing both the magnitude and pattern of coho recruitment each year was increased in the logged watersheds. Peak flow during storms increased; intragravel dissolved oxygen levels decreased in the stream draining the clear-cut watershed. These changes, however, were apparently within the range of variation that the coho naturally experience. Increased stream temperatures and mortalities, due to the logging effects, altered the post-recruitment life conditions of the coho in that stream but did not significantly affect the final smolt yield. The nocturnal behavior of recently emerged fry leads to recruitment along the stream length. Fry tend to emerge en masse from the redds at night, and large numbers proceed immediately to disperse downstream. This migration continues for several successive nights, beginning each night soon after dark. Evidence is presented indicating that fry emigration is primarily a dispersal mechanism that distributes fry from redd sites to nursery areas. It is hypothesized that the series of events leading from fry dispersal to be quiescent behavior at night, characteristic of resident fry, is a developmental sequence involving the physiology and maturity of the fry, modified by agonistic activity. Adjustments in coho population size were largely accomplished by fall, resulting in stable and characteristic population levels in each stream. A stable smolt yield was a further result. These adjustments are accomplished through high mortality during the months of the first spring and summer. This mortality is likely density dependent and related to the territorial and agonistic behavior of the fish. Growth, biomass, and net production varied greatly during each year. Seasonal changes in growth rate resulted in seasonal variations in biomass that were in contrast to the stabilized trends of population number. The pattern of net production rate was also largely determined by the seasonal growth pattern, and like biomass, did not show: a tendency to stabilize with time. It averaged 5 g/m2 among the three streams for the period June 1 to April 15. The coho populations seem naturally regulated most importantly with respect to number. The patterns of biomass and rate of net production may be understood as an interaction of seasonally variable growth rate with stabilizing population numbers. This study has shown that coho streams normally produce characteristic levels of smolt yield in spite of large natural variations in fry input and conditions for growth. The range of environmental variation for which this result holds may include short-term changes due to logging. However a normal population response to such a severe alteration as occurred on Needle Branch is very likely conditional upon a program that at least includes vigorous stream clearance, the restriction of additional mortality to early summer, when population adjustments are far from complete, and the encouragement of streamside revegetation. A streamside buffer strip of trees is an effective way of protecting aquatic resources.
Author : Corvallis Environmental Research Laboratory
Publisher :
ISBN 13 :
Total Pages : 120 pages
Book Rating : 4.:/5 (319 download)
Download or read book Effects of selected herbicides on smolting of coho salmon written by Corvallis Environmental Research Laboratory and published by . This book was released on 1979 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Andrew P. Hendry
Publisher : Springer Science & Business Media
ISBN 13 : 9401005850
Total Pages : 528 pages
Book Rating : 4.4/5 (1 download)
Download or read book Microevolution Rate, Pattern, Process written by Andrew P. Hendry and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: From guppies to Galapagos finches and from adaptive landscapes to haldanes, this compilation of contributed works provides reviews, perspectives, theoretical models, statistical developments, and empirical demonstrations exploring the tempo and mode of microevolution on contemporary to geological time scales. New developments, and reviews, of classic and novel empirical systems demonstrate the strength and diversity of evolutionary processes producing biodiversity within species. Perspectives and theoretical insights expand these empirical observations to explore patterns and mechanisms of microevolution, methods for its quantification, and implications for the evolution of biodiversity on other scales. This diverse assemblage of manuscripts is aimed at professionals, graduate students, and advanced undergraduates who desire a timely synthesis of current knowledge, an illustration of exciting new directions, and a springboard for future investigations in the study of microevolution in the wild.
Author : Jennifer Lee Nielsen
Publisher :
ISBN 13 :
Total Pages : 334 pages
Book Rating : 4.:/5 (33 download)
Download or read book Environment and Behavior Affecting Growth and Development of Juvenile Coho Salmon (Oncorhynchus Kisutch). written by Jennifer Lee Nielsen and published by . This book was released on 1990 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Nurney Harold Richman
Publisher :
ISBN 13 :
Total Pages : 236 pages
Book Rating : 4.:/5 (27 download)
Download or read book Hormones and Osmoregulation in Developing Coho Salmon (Oncorhynchus Kisutch) written by Nurney Harold Richman and published by . This book was released on 1985 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Ned Jay Knight
Publisher :
ISBN 13 :
Total Pages : 210 pages
Book Rating : 4.:/5 (912 download)
Download or read book Factors Affecting the Smolt Yield of Coho Salmon (Oncorhynchus Kisutch) in Three Oregon Streams written by Ned Jay Knight and published by . This book was released on 1979 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data from the coho salmon migration were examined from three streams of the Alsea Watershed Study, conducted on tributaries to Drift Creek, Oregon, from 1959 through 1973. With the migration season defined as November 1 through May 31, the mean seasonal smolt count was 2022 fish in Deer Creek, 665 in Flynn Creek, and 277 in Needle Branch. A general decline in numbers in the later years of the study was countered by a significant increase in mean length. The peak migration time was in late March and early April in each stream. A general approach to correlate physical and biological factors to the total seasonal smolt count in each stream through single regression analyses was mostly unsuccessful. A hypothesized positive relationship between summer discharge and smolt yield could not be supported, either by using mean monthly or mean maximum flows. A negative relationship between winter discharge and smolt count was hypothesized, due to increased mortality from higher flows. This hypothesis was supported by significant regressions that included mean January flows and mean highest flows. Summer temperatures (mean monthly and mean maximum for 7, 15, and 30 days) showed little correlation with the smolt output. Suspended sediment concentrations were negatively correlated with the number of smolts, as expected from the close relationship between sediment and streamflow. September biomass of juveniles in Flynn Creek was significantly related to the smolt output, though the relationships were weaker in the other two streams. The number of spawning females was positively related to the resulting smolt count but the correlations were not significant. Cutthroat trout biomass showed very little correlation with the coho smolt output. Combinations of variables in multiple regression analyses proved generally more successful than the single correlations with smolt count, but interpretation of the variables that proved significant was not always clear. For Deer Creek, 63.9% of the variability in smolt yield could be explained by the regression with September biomass and mean May maximum temperatures. September biomass, January discharge, and mean sediment concentration accounted for 80.7% of the variability in Flynn Creek smolt output. Only 53.8% of the variability in Needle Branch smolt count could be adequately explained (from January discharge and timing of the mean lowest discharge for 15 days), perhaps due to changes in stream variables following logging. When total smolt weight (biomass) was used as the dependent variable instead of count, only the Flynn Creek regression was significant (R2=0.888, with September biomass, mean lowest discharge for 15 days, and spawning female count). It is evident from these analyses that the juvenile populations in each stream have different relationships with various physical and biological factors. Other studies have shown strong positive relationships between commercial catch of coho salmon off Oregon and Washington and streamflow two years previously, corresponding to the freshwater residence period of the juveniles. In this study, however, negative relationships between winter discharge and smolt output were found. It seems that this negative correlation is masked by downstream, estuary, or ocean factors that are inherent in the relationships between catch and flow.
