Download or read book Life History Patterns of the Mattole River Steelhead Oncorhynchus Mykiss written by Kathy Lynn Day and published by . This book was released on 1996 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Early Marine Growth Patterns of Situk River Steelhead Oncorhynchus Mykiss written by Matthew R. Catterson and published by . This book was released on 2017 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steelhead Oncorhynchus mykiss exhibit complex life-history patterns described by variable freshwater and marine residency periods, maturation patterns, and reproductive characteristics. Over 300 small populations of Steelhead are present in Southeast Alaska, and similar trends in abundance among these populations suggest the influence of population-regulating forces operating on a regional scale. The Situk River, near Yakutat, Alaska, supports the largest known population of Steelhead in Alaska. Stock assessment studies on this river have collected the longest set of biological data and scale samples for Steelhead in the state. For this study, retrospective scale pattern analysis of samples from Situk River Steelhead was synthesized with regional abundance information to investigate patterns in early marine growth among different life-history and demographic groups, as well as to explore linkages between growth, abundance, and marine environmental variables. Positive correlations were identified between freshwater growth, first ocean-year growth, and adult length, while first ocean-year growth was negatively correlated with second ocean-year growth. Early maturing Steelhead were found to have increased first ocean-year growth and reduced adult length relative to later maturing Steelhead, confirming connections between growth and maturation. Correlations in abundance among Southeast Alaska Steelhead populations suggest that marine and climatic drivers may impact these populations in a regionally coherent manner. Correlations among patterns in abundance also varied along a distance gradient: populations located closer to the Situk River were more correlated with the Situk River than more distant populations. Positive relationships between Gulf of Alaska sea surface temperature, North Pacific Gyre Oscillation, and Situk River Steelhead abundance further supported the importance of climate-driven marine conditions to Steelhead productivity. While conservation concerns for Steelhead in Southeast Alaska are currently minimal, proactive investigations into life-history diversity and population linkages may become more relevant with increased marine ecosystem variability related to climate change.

Download or read book The Biology of the Juvenile Steelhead Oncorhynchus Mykiss in the Mattole River Estuary lagoon California written by Paul A. Zedonis and published by . This book was released on 1992 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Possible Decline in the Half pounder Life History Among Trinity River Steelhead Oncorhynchus Mykiss written by Matt L. Peterson and published by . This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Steelhead Trout written by Trey Combs and published by . This book was released on 1971 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Age Growth and Life History of Klamath River Basin Steelhead Trout Oncorhynchus Mykiss Irideus as Determined from Scale Analysis written by James S. Hopelain and published by . This book was released on 1998 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Escapement and Life History Patterns of Adult Steelhead in Freshwater Creek California written by Seth Ricker and published by . This book was released on 2002 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extended Residency and Movement Behavior of Juvenile Steelhead Oncorhynchus Mykiss in the Russian River Estuary California written by Joshua A. Fuller and published by . This book was released on 2011 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Colonization of Steelhead Oncorhynchus Mykiss After Barrier Removal in a Tributary to the Methow River Washington written by Dana Elizabeth Weigel and published by . This book was released on 2013 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Connectivity is important to the long-term persistence of populations allowing individuals to access essential habitats, and provide demographic support and genetic exchange among local populations. This exchange of individuals among populations increases genetic variation and the evolutionary potential of the species. Barriers to migration create fragmentation and isolation which interrupts these processes. This study explores the effects of small irrigation diversion dams on the migration of steelhead ( Oncorhynchus mykiss ) in tributaries to the Methow River, and the subsequent colonization of the anadromous life history after re-designing these diversions to allow passage. Passive integrated transponder tags were used with microsatellite markers to identify life history, source of colonizers and successful reproduction. Migratory O. mykiss successfully colonized Beaver Creek and offspring from the first two brood years successfully returned to the stream as adults. Inter-breeding between the tluvial and anadromous life history types was common and offspring from the fluvial parents returned to the basin as adult steelhead. Hatchery O. mykiss did not contribute to the first two brood years during this early colonization process despite high abundances in adult returns. Population genetic diversity and the percent hatchery admixture were significantly different at the lowest two monitoring sites in the stream after barrier treatment. Colonization was still progressing upstream one generation after barrier treatment (4-5 years). Migration estimates prior to treatment of the diversion dams indicated that there was no migration for at least a generation in Beaver Creek. Comparisons with migration to no migration sites in reference streams (Libby and Gold creeks) found significant differences in distance, number of obstructions, obstruction height to depth ratio and stream gradient. However, when examining Beaver Creek in comparison to sites with migration in the reference streams, only the number of obstructions was significantly different. Diversion dams on Beaver Creek were preventing migration and the treatment of these barriers resulted in the re-colonization of the migratory life histories. The fluvial life history was important in the colonization process and acts as a genetic reserve for the wild genotypes.

Download or read book Born to Run written by Matthew R. Sloat and published by . This book was released on 2013 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steelhead and rainbow trout are common names for marine-migratory (anadromous) and freshwater-resident forms of Oncorhynchus mykiss, a partially migratory salmonid fish. Anadromous and resident forms are sympatric and can produce offspring with a life history different from their own (i.e., steelhead parents can produce rainbow trout offspring and vice versa). The expression of these alternative life histories is a plastic response to individual patterns of energy acquisition, assimilation, and allocation during juvenile life stages. Individual performance during early stream life is of particular interest because of potential carry-over effects on subsequent growth and developmental trajectories. In a series of experiments in laboratory streams, I determined the influence of individual variation in energy metabolism on behavior, growth, and life-history expression in O. mykiss. Individual variation in energy metabolism was a strong predictor of feeding territory acquisition by juvenile fish during the transition from dependence on maternal provisioning of egg yolk reserves to independent feeding. Feeding territory acquisition was positively associated with standard metabolic rate (SMR) under conditions of an abundant and predictable food supply. When the density of intraspecific competitors was manipulated, the association between SMR and territory acquisition was strongest at intermediate stocking densities, moderate at the highest stocking densities, and weakest at the lowest stocking densities. However, reducing the spatial predictability of food resources within streams reversed the influence of SMR on competitive outcomes. These experiments determined that variation in ecological conditions during early life stages imposes different selection regimes on juvenile O. mykiss and results in physiological divergence among cohorts. Subsequent rearing experiments determined that behavioral dominance influences rates of anadromy and freshwater maturation, most likely through the association between SMR and territory acquisition. In addition to the effects of behavioral dominance, I observed a significant influence of sex, rearing temperature, and individual growth trajectories on the expression of anadromy and freshwater maturation. Partially migratory populations of O. mykiss maintain an exceptionally diverse portfolio of life-history strategies. Results from this work lend insight into a suite of behavioral and physiological processes influencing individual life histories.

Download or read book Identifying Historical Populations of Steelhead Within the Puget Sound Distinct Population Segment written by James Miles Myers and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Puget Sound Steelhead Technical Recovery Team (PSS TRT) convened in March 2008 to review information relevant to the identification of historical demographically independent populations (DIPs) of steelhead (Oncorhynchus mykiss) in the Puget Sound steelhead distinct population segment (DPS). The PSS TRT identified three major population groups (MPGs) containing a total of 32 steelhead DIPs in Puget Sound. Steelhead in the Puget Sound DPS exhibit two distinct life history strategies: summer-run and winter-run migrations. Winter-run steelhead, also known as ocean-maturing steelhead, return to freshwater during the winter and early spring months and spawn relatively soon after entering freshwater. Alternatively, summer-run (stream-maturing) steelhead return to freshwater during late spring and early summer in a relatively immature state and hold there until spawning in the following winter/spring. Generally, but not necessarily, summer-run steelhead return-timing is coordinated with river flow patterns that allow access past barriers to headwater spawning areas. Presently and historically, winter-run steelhead numerically represent the predominant life history type in Puget Sound"--Executive summary.

Download or read book Identifying Historical Populations of Steelhead Within the Puget Sound Distinct Population Segment written by James M. Myers and published by . This book was released on 2015 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Puget Sound Steelhead Technical Recovery Team (PSS TRT) convened in March 2008 to review information relevant to the identification of historical demographically independent populations (DIPs) of steelhead (Oncorhynchus mykiss) in the Puget Sound steelhead distinct population segment (DPS). The PSS TRT identified three major population groups (MPGs) containing a total of 32 steelhead DIPs in Puget Sound. Steelhead in the Puget Sound DPS exhibit two distinct life history strategies: summer-run and winter-run migrations. Winter-run steelhead, also known as ocean-maturing steelhead, return to freshwater during the winter and early spring months and spawn relatively soon after entering freshwater. Alternatively, summer-run (stream-maturing) steelhead return to freshwater during late spring and early summer in a relatively immature state and hold there until spawning in the following winter/spring. Generally, but not necessarily, summer-run steelhead return-timing is coordinated with river flow patterns that allow access past barriers to headwater spawning areas. Presently and historically, winter-run steelhead numerically represent the predominant life history type in Puget Sound"--Executive summary.

Download or read book Ecology and Distribution of Steelhead Oncorhynchus Mykiss in the Eel River California written by Samantha Heather Kannry and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Run-timing in salmonids is a prime example to study adaptive complexity in an iconic, culturally and economically important species. The Eel River in Northwestern California represents the southernmost extant population of summer-run steelhead in North America and is at the near-limit of the species’ thermal tolerance. It therefore presents an ideal location to examine the genetic basis for run-timing variations. Here we examine a number of issues related to steelhead conservation: 1) the extent to which upstream passage is blocked by ostensible physical barriers to dispersal; 2) spawning and rearing distribution of the two run-timings; 3) distribution of resident and anadromous genotypes; and 4) genetic diversity in a population of resident trout isolated above an impassable dam for nearly a century. Using Rapture (RAD Capture), we called genotypes at the region diagnostic for run-timing (GREB1L) and the region strongly associated with residency/anadromy in steelhead (OMY5). Remarkably, we concluded steelhead are passing a waterfall that has been managed as a complete barrier to anadromy. We also observed distinct spatial segregation between winter and summer-run steelhead in both the Middle Fork Eel and Van Duzen Rivers. Finally, we found evidence that prior to dam construction, summer-run steelhead inhabited the upper mainstem Eel, and that both life-history and overall genetic diversity are currently maintained in the resident trout population. Resident trout above the dam are well-suited to re-colonize the upper watershed if upstream passage were to be restored through the upcoming FERC re-licensing process.

Download or read book Parallel Evolution of the Summer Steelhead Ecotype in Multiple Populations From Oregon and Northern California written by Martha Angelica Arciniega Hernandez and published by . This book was released on 2017 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parallel adaptive divergence of migratory and reproductive behavior can occur in multiple populations when similar selection is acting on these traits. Timing of migration, sexual maturity, and reproduction can have major impacts on the dynamics and viability of a population. Life-history variation in steelhead, Oncorhynchus mykiss, including variation in anadromous run timing, reproductive maturity and spawn timing, represents an important aspect of their biology and adaptation to local habitats. Here we present a genetic analysis of naturally spawning steelhead to evaluate the genetic relationships and ancestry of summer- and winter-run reproductive ecotypes from multiple river basins in Oregon and Northern California. We infer the phylogeographic relationships among populations of both summer- and winter-run steelhead ecotypes using 12 microsatellite loci and 90 single nucleotide polymorphisms. Phylogenetic trees and analysis of molecular genetic variance revealed that pairs of phenotypically and genetically distinct reproductive ecotypes within rivers were each other's closest relatives. Isolation by distance was also observed, confirming that genetic relatedness was strongly associated with geographic distance, and indicating limited migration or gene flow among river basins. These patterns support the hypothesis that the summer-run steelhead ecotype has repeatedly evolved through parallel evolution in multiple river basins. These results, together with further investigation of the underlying molecular basis for the divergence of winter- and summer-run steelhead life-history traits, will inform management and conservation efforts for these ecotypes and improve our understanding of the role of adaptive variation in conservation genetics.

Download or read book Effects of Reclaimed Wastewater Effluent on Early Life History of Steelhead Trout Oncorhynchus Mykiss written by Andrew J. Jensen and published by . This book was released on 2003 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tradeoffs of Juvenile Steelhead Oncorhynchus Mykiss Rearing in an Intermittently Closed Estuary Northern California USA written by William Carson Matsubu and published by . This book was released on 2019 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estuarine environments provide an essential habitat to many aquatic animals and, in some settings, can be susceptible to drastic environmental transformations caused by deviations in connectivity with the ocean. In these intermittently closed estuaries (ICEs), the presence or absence of a barrier beach, naturally controlled by wave action and river flow, determines the mouth state (closed or open). Depending on the frequency and duration of closures and reopenings, ICEs can create a conundrum for inhabitants, especially diadromous fish that must transit between marine and freshwater habitats to reproduce. Changes in connectivity to the ocean not only obstructs migration between the ocean and the river but can also cause deadly conditions, especially for juvenile pacific salmonids (Oncorhynchus spp.) that have a narrow range of physiological tolerances for the abiotic variables susceptible to large fluctuations in ICEs. Despite these hurdles, ICEs constitute essential habitats for threatened populations of steelhead (Oncorhynchus mykiss). This dissertation utilizes a threatened population of juvenile steelhead in the Russian River estuary, northern California, USA as a case study to examine an array of relevant topics about the efficacy of a juvenile anadromous fish occupying an ICE. The intersection of a threatened fish with a plastic and complex life history within an understudied system provides many challenges as well as opportunities. In addition to a brief introduction (Chapter 1) and conclusion (Chapter 6), the main chapters of this dissertation (Chapters 2-5) will address knowledge gaps specific to juvenile steelhead in the Russian River estuary. The second chapter addressed uncertainties regarding what abiotic conditions juvenile steelhead are exposed to and how steelhead may avoid physiologically stressful conditions. Specifically, we answered the following questions: (1) "What are the WQ habitats used by juvenile steelhead during open and closed conditions in an ICE?" and (2) "What behavioural change is evidenced between open and closed conditions that might alter the juvenile steelhead's risk of exposure to stressful WQ?" To answer these questions, we combined thermal sensor encoded acoustic telemetry and coincidental WQ sampling. Chapter two determined that, under open conditions, juvenile steelhead experienced primarily brackish and saline water in the lower and middle reaches and warm freshwater in the upper reach, whereas under closed conditions, they moved greater distances and were found to be aggregating near cool water refugia not used during open mouth conditions. These findings shed light on the abiotic conditions juvenile steelhead are exposed to and emphasize the importance of tributary hydrogeomorphic processes and groundwater linkages in subwatersheds that are sources of cool water refugia in ICEs. The purpose of the third chapter was to evaluate the vertical response of juvenile steelhead to the physiochemical conditions (i.e., temperature, DO, salinity) in the Russian River estuary. This chapter further explored the acoustic telemetry and simultaneously collected WQ data from chapter two to test the following hypotheses: (i) juvenile steelhead will shift their position in the water column based on prevailing physiochemical conditions; (ii) the degree to which juvenile steelhead adjust their position in the water column will vary with fish size; and (iii) smaller juvenile steelhead will risk potentially stressful conditions to take advantage of prey sources. The results indicated the depth of fish varied in response to the present abiotic conditions and typically reflected the occupation of more energetically and physiologically beneficial habitats, with smaller fish being shallower in the water column when proximate salinities are higher. Results indicated management activities that promote open mouth conditions may create challenges for steelhead that are not acclimated to saline conditions but reveal foraging strategies used by juvenile steelhead that are not yet tolerant of higher salinities. Macroinvertebrates are fundamental to the food webs, yet their response to management activities that affect connectivity to the ocean is not well understood. The fourth chapter used systematic sampling of the benthic and epibenthic macroinvertebrates to assess factors that affect the diversity and abundance of key food web taxa. Similar to other ICEs, the macroinvertebrate assemblage of the Russian River estuary was primarily composed of taxa that can deal with the variability, either physiologically or behaviourally. Furthermore, the prominent food web taxa were abundant during both open and closed mouth conditions and were found in large aggregations in habitat only inundated during closed mouth conditions. These increased densities in the closure-inundated habitat may reflect more expansive aggregations of key food web taxa that would lead to more efficient foraging for juvenile steelhead. Although the growth rates of juvenile steelhead in ICEs have been reported near the highest in literature, leading to increased marine survival, the specific factors contributing to this growth have not been specifically evaluated. The fifth chapter incorporated observed growth rates, a diet analysis, and thermal history of juvenile steelhead into a bioenergetics model to explore factors that most influence the growth potential of juvenile steelhead. In this chapter, I confirmed that growth rates of juvenile steelhead in the Russian River estuary rival the highest in literature and are attributed to ample foraging opportunities and the ability of juvenile steelhead to thermo-regulate behaviourally in the heterogeneous abiotic environment. Higher energetic costs due to higher temperatures in the upper reach were possibly buffered by the consumption of more energy dense prey. These results indicated that growth is likely not limiting the recovery of threatened steelhead in the Russian River estuary. With many populations of salmonids imperiled near their southern range, efforts for recovery could benefit from protecting habitats in ICEs and considering the impacts of management activities to the water quality conditions.

Download or read book Influence of Early Life Growth and Precipitation Zone on Survival to Adulthood in Wild Steelhead Trout Oncorhynchus Mykiss in the Skagit River Basin WA written by Jamie N. Thompson and published by . This book was released on 2013 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wild Steelhead Trout, Oncorhynchus mykiss, in the Puget Sound are currently in decline, and very little is known about the early life history of these threatened fish. This study evaluated consequences of early life growth in terms of survival to smolt or adult stages. The objectives of this study were to determine whether significant size-selective mortality (SSM) in Steelhead could be detected between freshwater stages and returning adults; and if so, how the magnitude of size selectivity varied among reaches categorized by three different precipitation zones (snow, mixed rain-snow, or rain). Wild Steelhead in the Skagit River basin were sampled as juveniles, smolts, and adults, and scales were measured to compare back-calculated freshwater growth rates and size distributions of rearing juveniles with individuals that survived from an earlier life stage to the smolt and adult stages. Linear regression of scale radius (SR) and fork length indicated that SR was a reasonable predictor of fork length during freshwater residency. Back-calculated size-at-annulus estimates indicated that fish sampled as adults grew significantly faster to age 1, 2, and 3 annuli compared to fish sampled as juveniles, and faster to the age 2 and 3 annuli compared to fish sampled as smolts. Within precipitation zones, fish sampled as juveniles were consistently smaller at each freshwater annulus compared to those same freshwater annuli on fish sampled as adults. An increased disparity in size-at-annuli 2 and 3 between fish sampled as juveniles, smolts, and adults suggests that fast growth during the period at which Steelhead smoltify is vitally important to survival to adulthood. These findings provide evidence that survival among life stages is an important dynamic in wild Steelhead, and can be attributed, in part, to size attained at earlier life stages. Efforts for recovery of threatened Puget Sound Steelhead could benefit by considering growth- and size-selective mortality in freshwater environments, and identifying factors that limit early life growth at a finer scale of habitat, for example among sub-basins or precipitation zones.