Download or read book Age Growth and Productivity of Juvenile Sockeye Salmon in Two High Latitude Lakes Alaska written by Lorna I. Wilson and published by . This book was released on 2009 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The growth of Seward Peninsula sockeye salmon (Oncorhynchus nerka) from Salmon and Glacial lakes is related to their physical environment. Dermal scales collected over many years were measured to document the annual age specific growth of smolts and adults. The effect of fertilization on fry growth was examined using the first year of growth. The growth histories of Salmon Lake sockeye salmon were compared to Glacial Lake sockeye salmon through smolting and in the marine environment. Annual age specific fry growth had no direct relationship to fertilization; however, there were interactions between biomass of salmon prey and fertilization, and between prey biomass and age of smolting. Glacial Lake age-1 smolts are the same size as Salmon Lake age-1 smolts, but age-1.3 Salmon Lake juveniles after their first year in the ocean are smaller than age-1.3 Glacial Lake juveniles suggesting lower size based mortality. The differences in growth histories show each population's response to lake production and mortality experienced by smolt between the rearing lake and the ocean"--Leaf iii.
Download or read book Ecological Studies of Sockeye Salmon and Related Limnological and Climatological Investigations Brooks Lane Alaska 1957 written by Theodore R. Merrell and published by . This book was released on 1964 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecological studies on the fresh-water phases of the life history of sockeye salmon and studies on related limnology and climatology were made at Brooks Lake, Alaska, in 1957. Data are presented and interpreted on adult sockeye salmon spawning distributions and behavior, age, sex, length, fecundity, and bear predation; on juvenile sockeye salmon ages, food, growth, migration from the lake, relative abundance, and distribution in the lake; and on climatological and limnological factors that may influence sockeye salmon behavior and abundance.
Download or read book Variation in the Early Life History of Sockeye Salmon Oncorhynchus Nerka written by Caryn A. Abrey and published by . This book was released on 2005 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evidence for Temperature Limitation of Juvenile Sockeye Salmon Oncorhynchus Nerka Growth in Hugh Smith Lake Alaska written by Larry Peltz and published by . This book was released on 1989 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Aspects of the Comparative Ecology of Fishes Associated with Juvenile Sockeye Salmon Oncorhynchus Nerka Walbaum in the Lakes of the Naknek River System Alaska written by Richard L. Wallace and published by . This book was released on 1969 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the distribution, relative abundance and diet of fishes sympatric with juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), within the freshwater nursery areas of the Naknek River system was undertaken from 1961 to 1963. The study was part of an extensive investigation to determine what factors in the freshwater environment were limiting the size of the populations of sockeye salmon returning to the rivers of Bristol Bay, Alaska. The speties found associated with juvenile salmon in the limnetic zones of the Naknek system were the pond smelt, Hypomesus olidus (Pallas); the least cisco, Coregonus sardinella Valenciennes; the threespine stickleback, Gasterosteus aculeatus Linnaeus; and the ninespine stickleback, Pungitius pungitius (Linnaeus). Life history information was collected for these sympatric species. Tow nets were used to capture samples of fish from the limnetic portions of the nursery areas. Some samples were collected by beach seines, lake traps and otter trawls. Plankton samples were collected and compared to the diets of the limnetic fishes. Although some confusion has existed in the literature, I concluded that pond smelt of the Naknek system belong to Hypomesus olidus (Pallas). The populations of smelt were comprised of six age-groups in the late summer, but most specimens belonged to three age-groups. Most members of the species spawn in the spring of the fourth year of life. The estimated fecundity ranged from 900 to 4,300 eggs per female. Seven age-groups of least ciscoes were present in the populations of the Naknek system. The species in the Naknek system probably spawned for the first time in the fall of their fourth year. The estimated fecundity of two specimens was 4,006 and 14,380 eggs. Populations of three spine stickleback were comprised of three age-groups of fish. I was unable to assign ages to ninespine stickleback. Estimates of the fecundity of the species ranged from 116 to 456 eggs per female. All species studied were distributed throughout the Naknek system. The relative abundance of the fishes studied was variable between and within nursery areas and from year to year. The population densities of pond smelt and threespine stickleback were larger in the surface waters compared to the deep waters. The relative abundance of sockeye fry, yearlings and ninespine stickleback was greater in the surface stratum rather than the deep stratum in most nursery areas. The five main food items utilized by these limnetic species were cladocerans (Bosmina sp. and Daphnia sp.); copepods (cyclopoid copepods and Diaptomus sp.); and Dipteran insects. Analysis of the similarity of diets indicated that the diets of sockeye fry and pond smelt were more similar than were the diets of sockeye fry or yearlings and any other sympatric species. The diet of sockeye fry was more similar to that of either species of stickleback than was the diet of sockeye yearlings. An analysis of the food of various sizes of each species of fish indicated the diets of three age-groups of smelt were more similar than the diets of various age-groups of any other fish. The food composition of three age-groups of ciscoes and two size groups of both species of stickleback showed a strong positive correlation. The diets of sockeye fry and yearlings showed the weakest positive correlation of the species studied. All species of fish studied selectively fed on one or more components of the zooplankton. Daphnia sp. and cyclopoid copepods were strongly selected in Lake Coville. Cyclopoids were selected in South Bay. Bosmina sp. was selected from the waters of West End. In Lake Coville, the greatest potential competition for food probably existed between the large populations of pond smelt and sockeye fry. In the West End nursery area, potential competition between juvenile salmon and both species of stickleback may not be severe, depending on the age composition of the salmon population present in the nursery area. The possibility exists that the relatively low numbers of adult sockeye salmon returning to the comparatively rich lakes of the Naknek River system is due to the presence of large populations of sympatric species of fish. Each of these sympatric species feed on the same general types of food organisms as do the juvenile salmon and may affect the numbers of young salmon that leave the lake, and subsequently return from the ocean.
Download or read book Growth Patterns of Juvenile Sockeye Salmon in Different Thermal Environments of Alaskan Lakes written by Jim A. Edmundson and published by . This book was released on 1997 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Juvenile Chilkat Lake Sockeye Salmon in Response to Density dependent and Environmental Factors written by Jodi Neil (C.) and published by . This book was released on 2018 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chilkat Lake, in northern Southeast Alaska, is home to a Sockeye Salmon Oncorhynchus nerka population that is an important component in local commercial, sport, and subsistence fisheries, and has been monitored since the late 1960s. The population began declining in the late 1980s, prompting fishery managers to evaluate the production potential of Chilkat Lake to determine if it could be a candidate for enhancement efforts such as fry stocking or lake fertilization. Sockeye Salmon fry were stocked into Chilkat Lake intermittently from 1989 to 2004 in both small- (
Download or read book Growth of Juvenile Sockeye Salmon Oncorhynchus Nerka Walbaum in Auke Lake Alaska written by Garvan Pat Bucaria and published by . This book was released on 1968 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feeding Ecology of Juvenile Sockeye Salmon in Afognak Lake Alaska written by Natura Richardson and published by . This book was released on 2016 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much attention has been given to juvenile Sockeye Salmon (Oncorhynchus nerka) ecology with particular focus on pelagic food webs in deep nursery lakes. In contrast, this study took place at Afognak Lake, Alaska, to better understand juvenile Sockeye Salmon foraging ecology, potential consumer interactions, and metabolic opportunities and constraints in a shallow nursery lake. I collected fish every two weeks from Afognak Lake from May through August, 2013. I described ontogenetic and temporal variation in the diets of juvenile Sockeye Salmon and a potential competitor, adult Threespine Stickleback (Gasterosteus aculeatus). Notably, this study revealed that adult aquatic insects are an important prey item for lake rearing juveniles. Threespine Stickleback diets showed some overlap with diets of juvenile Sockeye Salmon; however, significant differences in diet composition suggest that Sockeye Salmon and Threespine Stickleback partition prey and habitat resources. I then used my field-derived temperature, demographic, and diet data as inputs to a bioenergetics model to estimate summer consumption rate and growth efficiency of juvenile Sockeye Salmon from Afognak Lake across a range of foraging scenarios. Consumption rate was greater and mean growth efficiency was lower for all littoral-use scenarios relative to pelagic-use scenarios. Further, daily consumption was lowest and mean growth efficiency was highest for model scenarios in which insects were a dominant component of the diet relative to scenarios in which zooplankton were the dominant prey. My findings highlight the importance of benthic-pelagic coupling in Sockeye Salmon nursery lakes and the potential for juveniles to navigate trade-offs between energy acquisition and thermal conditions across lake habitats.
Download or read book Effects of Climate and Density on the Distribution Growth and Life History of Juvenile Sockeye Salmon Oncorhynchus Nerka in Iliamna Lake Alaska written by Harry B. Rich and published by . This book was released on 2006 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Linking Freshwater Growth to Size dependent Marine Survival of Sockeye Salmon written by Marta Elizabeth Ree and published by . This book was released on 2019 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the mediating role of body size in determining fitness, the ‘bigger is better’ hypothesis still pervades evolutionary ecology despite evidence that natural selection on phenotypic traits varies in time and space. For Pacific salmon (genus Oncorhynchus), the size at which juveniles migrate to sea (i.e., smolts) has been linked to survival during the early marine period, where larger smolts typically survive at a higher rate than their smaller counterparts. However, the relationship of smolt size and survival becomes more ambiguous when considering confounding factors of age, ocean entry timing, and environmental variability. Despite equivocal results, smolt size appears to be a key trait and therefore changes in freshwater conditions may have consequences for population productivity. Furthermore, due to differences in site-specific habitats, trophic dynamics, and population traits the response of specific populations to these changes is likely to be context specific. The objective of this thesis was to 1) quantify the direction and magnitude of natural selection on smolt size for three age classes of sockeye salmon in a small watershed on Kodiak Island, AK and 2) explore stock-specific effects of temperature and conspecific density on smolt size over a multi-decade time-series to understand historic and possible future trends. To address our first objective, we calculated standardized selection differentials by comparing observed size distributions of out-migrating juvenile salmon to back-calculated smolt length from the scales of surviving, returning adults. Results reveal the magnitude of selection on size was very strong and consistent among years. However, the direction of selection on size consistently varied among age classes. The absolute magnitude of selection was negatively correlated to apparent marine survival and positively correlated to late mean ocean entry timing. To address our second objective, we back-calculated smolt size from returning adult scales to reconstruct a time-series of smolt length of two stocks within a small Alaska watershed on Kodiak Island. Using a dynamic linear model framework, we detected evidence that for one stock, temperature was important in explaining smolt length, and density effects influenced both stocks utilizing the same lakes. Furthermore, forecasts of smolt length showed highly variable responses under scenarios of increasing temperature and high and low densities. Collectively, these results demonstrate that interactions between processes of climate, density, and natural selection are highly context-specific in terms of both inter- and intra- population variability.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2013 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 842 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Production of Juvenile Atlantic Salmon Salmo Salar in Natural Waters written by National Research Council Canada and published by NRC Research Press. This book was released on 1993 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up-to-date information, knowledge and research in progress in scientific fields related to natural production of juvenile Atlantic salmon and some other ecologically similar fluvial salmonids is contained in the 25 papers and 12 abstracts contained in this publication, which were prepared for an international symposium held in St. John's, Newfoundland. Studies relate to stream ecology, invertebrates and predators, habitat improvement, competitive effects, behaviour and dispersal, habitat and production of juvenile salmon, population dynamics and relationships of juvenile salmon estimates to smolt yields. A list of participants at the conference is also provided.
Download or read book Book Catalog of the Library and Information Services Division Author title series indexes written by Environmental Science Information Center. Library and Information Services Division and published by . This book was released on 1977 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long term Environmental Change in Arctic and Antarctic Lakes written by Reinhard Pienitz and published by Springer Science & Business Media. This book was released on 2007-11-08 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns about the effects of global climate change have focused attention on the vulnerability of circumpolar regions. This book offers a synthesis of the spectrum of techniques available for generating long-term environmental records from circumpolar lakes.
Download or read book Oceanic Abstracts written by and published by . This book was released on 1996 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt:
