Download or read book The Abundance of Epibenthic and Planktonic Macrofauna and Feeding Habits of Juvenile Fall Chinook Salmon Oncorhynchus Tshawytscha in the Mattole River Estuary Lagoon Humboldt County California written by Morgan S. Busby and published by . This book was released on 1991 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mattole River Watershed Assessment Report written by and published by . This book was released on 2003 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Water Quality Monitoring in the Klamath River Estuary 1991 1994 written by Michael Wallace and published by . This book was released on 1998 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book California Fish and Game written by and published by . This book was released on 1995 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inland Fisheries Administrative Report written by and published by . This book was released on 1998 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Juvenile Chinook Salmon written by Douglas A. Young and published by . This book was released on 1987 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predation by Sculpins on Fall Chinook Salmon Oncorhynchus Tshawytscha Fry of Hatchery Origin written by Benjamin G. Patten and published by . This book was released on 1971 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Food Habits Growth and Emigration of Juvenile Chinook Salmon Oncorhynchus Tshawytscha from a Stream pond Environment written by Jon Joseph Lauer and published by . This book was released on 1969 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feeding Ecology and Growth of Juvenile Chinook Salmon Oncorhynchus Tshawytscha During Early Marine Residence written by Marisa Norma Chantal Litz and published by . This book was released on 2017 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The early marine phase following freshwater emigration has been identified as a critical period in salmonid (Oncorhynchus spp.) life history, characterized by high but variable mortality. Consistent with the “growth-mortality” and “bigger-is-better” hypotheses, at least some of the mortality during the critical period appears to be size-dependent – with smaller or slower growing individuals less likely to survive than larger, faster growing conspecifics. Size and growth are flexible morphological traits that vary with prey availability, yet there is incomplete information on the temporal and spatial match/mismatch between juvenile salmonids and their marine prey in the Northern California Current Ecosystem. This work addressed a gap in the understanding of seasonal variability in prey community composition, abundance, and quality during early marine residence. Three studies were conducted using a population of subyearling (age-0) Chinook salmon (O. tshawytscha) from the upper Columbia River in order to evaluate the effects of prey on salmon growth, biochemistry, and performance. The first was a laboratory study that tested for growth rate and swimming speed differences in salmon reared on three treatment diets followed by three fasting treatments to assess the effects of variability in summer diet quality and winter diet quantity. Significant differences in growth were detected among fasting treatments but not diet treatments. Also, larger salmon with more storage lipids swam faster than smaller leaner fish following fasting, indirectly supporting the notion that growth during the critical period provides a carryover benefit important for overwinter survival. Salmon fatty acids and bulk stable isotopes of carbon and nitrogen were measured throughout the experiment to provide estimates of turnover and incorporation rates. The next study was a longitudinal field study that measured variation in salmon size and prey field community throughout the early ocean period (May – September) over two years of high marine survival (2011 and 2012) to better understand the relationship between prey community composition and salmon growth. Maximum growth rates were associated with high biomass of northern anchovy (Engraulis mordax) which peaked in abundance at different times in each year. The final bioenergetics modeling study combined data from the laboratory and field studies to evaluate the relative importance of prey availability, prey energy density, and temperature on salmon growth. Variation in feeding rate was related most with growth rate variability and least with prey energy density. Throughout their range, subyearlings can grow at high rates in the ocean (>2% body weight per day) by consuming both invertebrate and marine fish prey. However, when marine fish prey are highly abundant they likely provide an energetic advantage over invertebrate prey by reducing overall foraging costs. Quantifying the abundance, size, diet, and distribution of juvenile salmonids relative to their prey field throughout early ocean residence will contribute to a better understanding of seasonal differences in trophic interactions that are associated with differences in annual growth and survival rates. Moreover, an integrated approach that combines sampling of prey with measurements of predator growth, diet, fatty acids, and stable isotopes provides a useful framework for assessing trophic dynamics and evaluating the effects of climate variability and change on predator and prey communities.
Download or read book Physiological Ecology of Juvenile Chinook Salmon Oncorhynchus Tshawytscha Rearing in Fluctuating Salinity Environments written by Crystal R. Hackmann and published by . This book was released on 2005 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estuaries provide juvenile salmonids with highly productive feeding grounds, refugia from tidal fluctuations and predators, and acclimation areas for smoltification. However, these dynamic, fluctuating salinity environments may also be physiologically stressful to growing juvenile fish. In order to evaluate the costs and benefits of estuarine marshes to juvenile Chinook salmon, I observed habitat use, diet, and growth of fish in the Nehalem Estuary on the Oregon coast. I also examined physiological costs associated with salmon living in fluctuating salinities and growth rates in laboratory experiments. I collected growth, diet and osmoregulation information from juvenile Chinook salmon in three tidal marsh sites in the Nehalem Bay and from juveniles in the Nehalem River. Stomach contents indicated that a high proportion of the diet is derived from terrestrial prey. These allochthonous prey resources likely become available during the flood stages of tidal cycles when drift, emergent and terrestrial insects would become available from the grasses surrounding the water. This field study confirmed that juvenile Chinook salmon utilized fluctuating salinity habitats to feed on a wide range of items including terrestrial-derived resources. Although field studies indicate that fish in estuarine habitats grow well and have access to quality prey resources, experimental manipulations of salinities were used to quantify the physiological costs of residing in the freshwater-saltwater transitional zone. In the laboratory, I designed an experiment to investigate the physiological responses to fluctuating salinities. Experimental treatments consisted of freshwater (FW), saltwater (SW) (22-25%o); and a fluctuating salinity (SW/FW) (2 - 25%o). These treatments were based on typical salinity fluctuations found in estuarine habitats. I measured length, weight, plasma electrolytes and cortisol concentrations for indications of growth and osmoregulatory function. The fluctuating salinity treatment had a negative effect on growth rate and initial osmoregulatory ability when compared with constant freshwater and saltwater treatments. The results indicated that fluctuating salinities had a small but marginally significant reduction in growth rate, possibly due to the additional energetic requirements of switching between hyper- and hypo-osmoregulation. However, 24-hour saltwater challenge results indicated that all fish were capable of osmoregulating in full-strength seawater. In a second experiment, I manipulated feed consumption rates of juvenile spring Chinook salmon to investigate the effects of variable growth rates on osmoregulatory ability and to test the validity of RNA:DNA ratios as indication of recent growth. The treatments consisted of three different feeding rates: three tanks of fish fed 0.7 5% (LOW) body weight; three tanks fed 3% (HIGH) body weight; and three tanks were fasted (NONE) during the experiment. These laboratory results showed a significant difference in the osmoregulatory ability of the NONE treatment compared to the LOW and HIGH treatments which indicates that a reduction in caloric intake significantly effected osmoregulatory capabilities during a 24 hour saltwater challenge. Furthermore, this suggests that there is a minimum energetic requirement in order to maintain proper ion- and osmoregulation in marine conditions. Estuarine marshes have the potential to provide productive feeding grounds with sufficient prey input from terrestrial systems. However, utilization of these marshes in sub-optimal conditions could alter behavior or impair physiological condition of juvenile Chinook salmon prior to their seaward migration by providing insufficient prey resources in a potentially stressful, fluctuating environment. Therefore, the physiological costs associated with estuarine habitat use should be well understood in order to aid future restoration planning.
Download or read book Feeding Habits and Condition of Juvenile Chinook Salmon in the Upper Sacramento River California written by Pamela Ann Petrusso and published by . This book was released on 1998 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimating Juvenile Chinook Salmon Oncorhynchus Tshawytscha Abundance from Beach Seine Data Collected in the Sacramento San Joaquin Delta and San Francisco Bay California written by Russell W. Perry and published by . This book was released on 2016 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Juvenile Chinook Salmon Oncorhynchus Tshawytscha Life History Diversity and Growth Variability in a Large Freshwater Tidal Estuary written by Pascale A. L. Goertler and published by . This book was released on 2014 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many fish and wildlife species, a mosaic of available habitats is required to complete their life cycle, and is considered necessary to ensure population stability and persistence. Particularly for young animals, nursery habitats provide opportunities for rapid growth and high survival during this vulnerable life stage. My thesis focuses on juvenile Chinook salmon (Oncorhynchus tshawytscha) and their use of estuarine wetlands as nursery habitat. Estuaries are highly productive systems representing a mosaic of habitats connecting rivers to the sea, and freshwater tidal estuaries provide abundant prey communities, shade, refuge from predation and transitional habitat for the osmoregulatory changes experienced by anadromous fishes. I will be discussing the freshwater tidal wetland habitat use of juvenile Chinook salmon in the Columbia River estuary, which are listed under the Endangered Species Act. I used otolith microstructural growth estimates and prey consumption to measure rearing habitat quality. This sampling effort was designed to target as much genetic diversity as possible, and individual assignment to regional stocks of origin was used to describe the diversity of juvenile Chinook salmon groups inhabiting the estuary. Diversity is important for resilience, and in salmon biocomplexity within fish stocks has been shown to ensure collective productivity despite environmental change. However much of the research which links diversity to resilience in salmon has focused on the adult portion of the life cycle and many resource management policies oversimplify juvenile life history diversity. When this oversimplification of juvenile life history diversity is applied to salmon conservation it may be ignoring critical indicators for stability. Therefore in addition to genetic diversity I also explore methods for better defining juvenile life history diversity and its application in salmon management, such as permitting requirements, habitat restoration, hydropower practices and hatchery management. This study addresses how juvenile salmon growth changes among a range of wetland habitats in the freshwater tidal portion of the Columbia River estuary and how growth variation describes and contributes to life history diversity. To do this, I incorporated otolith microstructure, individual assignment to regional stock of origin, GIS habitat mapping and diet composition, in three habitats (mainstem river, tributary confluence and backwater channel) along ~130 km of the upper estuary. For my first chapter I employed a generalized linear model (GLM) to test three hypotheses: juvenile Chinook growth was best explained by (1) temporal factors, (2) habitat use, or (3) demographic characteristics, such as stock of origin or the timing of seaward migration. I found that variation in growth was best explained by habitat type and an interaction between fork length and month of capture. Juvenile Chinook salmon grew faster in backwater channel habitat and later in the summer. I also found that mid-summer and late summer/fall subyearlings had the highest estuarine growth rates. When compared to other studies in the basin these juvenile Chinook grew on average 0.23, 0.11-0.43 mm/d in the freshwater tidal estuary, similar to estimates in the brackish estuary, but ~4 times slower than those in the plume and upstream reservoirs. However, survival studies from the system elucidated a possible tradeoff between growth and survival in the Columbia River basin. These findings present a unique example of the complexity in understanding the influences of the many processes that generate variation in growth rate for juvenile anadromous fish inhabiting estuaries. In my second chapter, I used otolith microstructure and growth trends produced in a dynamic factor analysis (DFA, a multivariate time series method only recently being used in fisheries) to identify the life history variation in juvenile Chinook salmon caught in the Columbia River estuary over a two-year period (2010-2012). I used genetic assignment to stock of origin and capture location and date with growth trajectories, as a proxy for habitat transitions, to reconstruct life history types. DFA estimated four to five growth trends were present in juvenile Chinook salmon caught in the Columbia River estuary, diversity currently being simplified in many management practices. Regional stocks and habitats did not display divergent growth histories, but the marked hatchery fish did ordinate very similarly in the trend loadings from the DFA analysis, suggesting that hatchery fish may not experience the same breadth of growth variability as wild fish. I was not able to quantify juvenile life history diversity, and juvenile Chinook life history diversity remains difficult to catalog and integrate into species conservation and habitat restoration for resource management. However, by expanding our understanding of how juvenile Chinook salmon experience their freshwater rearing environment we improve our capacity to conserve and manage salmon populations. The findings from my thesis provide the necessary information for a restoration framework to link habitat features with salmon management goals, such as juvenile growth, wild and genetic origin and life history diversity.
Download or read book Growth and Abundance of Juvenile Fall Chinook Salmon in Sixes River Estuary 1969 written by Paul E. Reimers and published by . This book was released on 1970 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution Habitat Use and Growth of Juvenile Chinook Salmon in the Metolius River Basin Oregon written by Jens C. Lovtang and published by . This book was released on 2005 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chinook salmon (Oncorhynchus tshawytscha) have been absent from their historic spawning and rearing grounds in the Metolius River Basin in central Oregon since 1968, when fish passage was terminated at the Pelton Round Butte Hydroelectric Project on the Deschutes River. Plans have been developed to reestablish passage of anadromous fish through the Project. However, only anecdotal evidence exists on the historic distribution of spring Chinook juveniles in the Basin. A recent approach to characterizing habitat quality for anadromous fishes in the Basin was the development of HabRate (Burke et al. In Press), which presented a relative quality rating of habitat based upon published fish-habitat relationships at the stream reach spatial scale. The present study was initiated to test the predictions of HabRate for summer rearing juvenile Chinook salmon in the Metolius Basin. Chinook salmon fry were released in the winters of 2002 and 2003, and their densities and sizes were quantified via snorkeling and fish collection in six unique study reaches in the upper Metolius River Basin. Each of these stream reaches varied in terms of temperature, habitat availability, invertebrate drift availability, and fish community composition. My observations were not consistent with the qualitative predictions of HabRate. Moreover, habitat utilization was not consistent among study reaches. Similar to other qualitative habitat rating models (e.g. Habitat Suitability Indices (Raleigh et al. 1986) and Instream Flow Incremental Methodology (Bovee 1982)), HabRate's predictions rely solely on physical habitat characteristics, with the assumption that habitat will be used consistently among stream reaches (i.e. a pool in one reach is of equal importance as a pool in another reach). My results suggest that the unique ecological setting of each study reach provides the context for understanding the patterns of growth, habitat use, and diurnal activity of juvenile Chinook salmon. The inclusion of ecological components, such as food availability, the bioenergetic constraints of temperature, and the risk of predation can make these models more biologically realistic. Growth of juvenile Chinook salmon among study reaches had a curvilinear relationship to water temperature, and was also positively related to the drift density of invertebrate biomass. In three collection seasons (fall 2002, spring 2003 and fall 2003) 41 to 69% of the variations in fork lengths were explained by a multiple regression model including temperature and invertebrate drift. Based on these findings, I present a conceptual growth capacity model based on the tenets of bioenergetics as a basis for understanding the relative quality of the habitat among stream reaches for juvenile Chinook salmon. Fish community composition can help to explain observed patterns in habitat utilization and diel activity patterns. In the study reaches that had a greater presence of adult trout (potential predators), observations of juvenile Chinook salmon in mid-channel habitat were infrequent to non-existent during the day and abundances were higher in all habitat types at night. In the study reaches with colder water temperatures, observed juvenile Chinook salmon densities were higher at night. I suggest that habitat selection and diurnal activity patterns in some study reaches are reflective of strategies taken by the fish to minimize risks of predation.
Download or read book Diet and Prey Resources of Juvenile Chinook Salmon Oncorhynchus Tshawytscha Rearing in the Littoral Zone of an Urban Lake written by Michele Elise Koehler and published by . This book was released on 2002 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Freshwater Habitat Utilization by Juvenile Fall Chinook Salmon Oncorhyncus Tshawytscha in Camp Creek Klamath Basin California written by Brenda J. Olson and published by . This book was released on 1997 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
