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Book Effects of Habitat and Predator prey Interactions on Stocked Sockeye Fry in Tatsamenie Lake

Download or read book Effects of Habitat and Predator prey Interactions on Stocked Sockeye Fry in Tatsamenie Lake written by Renate R. Riffe and published by . This book was released on 2006 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tatsamenie Lake has been stocked with marked sockeye salmon fry since 1991, as part of a program initiated by the Pacific Salmon Commission to increase annual returns of sockeye salmon (Oncorhynchus nerka) to the Taku River system by 100,000 fish annually. However, the average annual commercial catch of stocked Tatsamenie sockeye salmon between 1995 and 2000 has been only about 2,000 fish. This study was conducted in 2001 and 2002 to ascertain whether predators were targeting stocked sockeye fry in the lake, and which species, if any, were responsible. Other questions investigated included whether age-0 stocked sockeye fry were migrating prematurely from the lake, and whether differences in water chemistry between Tatsamenie Lake and the incubating hatchery were depressing stocked-fry survival rates.

Book Canadian Journal of Fisheries and Aquatic Sciences

Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 1995-10 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Journal of the Fisheries Research Board of Canada

Download or read book Journal of the Fisheries Research Board of Canada written by Fisheries Research Board of Canada and published by . This book was released on 1978 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Predation of Sockeye Salmon Fry by Cottids and Other Predatory Fishes in the Cedar River and Southern Lake Washington 1997

Download or read book Predation of Sockeye Salmon Fry by Cottids and Other Predatory Fishes in the Cedar River and Southern Lake Washington 1997 written by Roger Tabor and published by . This book was released on 1998 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Pacific Salmon their Ecosystems

Download or read book Pacific Salmon their Ecosystems written by Deanna J. Stouder and published by Springer Science & Business Media. This book was released on 2012-02-02 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: The symposium "Pacific Salmon and Their Ecosystems: Status and Future Options',' and this book resulted from initial efforts in 1992 by Robert J. Naiman and Deanna J. Stouder to examine the problem of declining Pacific salmon (Oncorhynchus spp.). Our primary goal was to determine informational gaps. As we explored different scientific sources, state, provincial, and federal agencies, as well as non-profit and fishing organizations, we found that the information existed but was not being communicated across institutional and organizational boundaries. At this juncture, we decided to create a steering committee and plan a symposium to bring together researchers, managers, and resource users. The steering committee consisted of members from state and federal agencies, non-profit organizations, and private industry (see Acknowledgments for names and affiliations). In February 1993, we met at the University of Washington in Seattle to begin planning the symposium. The steering committee spent the next four months developing the conceptual framework for the symposium and the subsequent book. Our objectives were to accomplish the following: (1) assess changes in anadromous Pacific Northwest salmonid populations, (2) examine factors responsible for those changes, and (3) identify options available to society to restore Pacific salmon in the Northwest. The symposium on Pacific Salmon was held in Seattle, Washington, January 10-12, 1994. Four hundred and thirty-five people listened to oral presentations and examined more than forty posters over two and a half days. We made a deliberate attempt to draw in speakers and attendees from outside the Pacific Northwest.

Book Relating the Sockeye Salmon Oncorhynchus Nerka Spawning Migrating Experience with Offspring Fitness

Download or read book Relating the Sockeye Salmon Oncorhynchus Nerka Spawning Migrating Experience with Offspring Fitness written by David A. Patterson and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adult Pacific salmon arrive at the Fraser River with a finite supply of energy to allocate between reproductive development and river migration, yet it is unknown if environmental conditions experienced by parents cause energetic trade-offs that ultimately affect offspring fitness. This thesis examined populations of Fraser River sockeye salmon (Oncorhynchus nerka) that differed in their mirgration distance (Weaver - 100 km, Gates - 363 km, and Early Stuart - 1086 km) to assess the hypothesis that migratory stress exerts an intergenerational effect on offspring fitness. When compared among three year classes of Early Stuart sockeye salmon, metrics for ovarian development at six locations along the migration route revealed no evidence of facultative adjustments of either egg number or egg size en route. In contrast, significant interannual variation existed for final ovary mass, egg size and egg number over a 16-year period, with reductions in ovary mass and egg size associated with years of high river discharge rate during the migration. Selection against maternal phenotypes with a high ovarian investment strategy was postulated as a mechanism to reconcile both data sets. Maternal and paternal gamete origin significantly influenced offspring survival. However, egg viability did not correlate with phenotypic variation in maternal energetic condition, osmoregulatory status, reproductive hormonal state, egg composition, stress, or moribund condition. Nevertheless, at the population level, migration severity may have impacted overall egg quality because (a) the two populations that experienced more severe migration conditions in 1999 and 2000 had the lowest overall embryo survival (Gates = 77%; Early Stuart = 81%; Weaver = 94%; - artifical fertilizations), and (b) a poor maternal condition (using pre-spawn mortality as surrogate of poor condition and adverse migration conditions) was positively correlated with low egg to fry survival in Early Stuart sockeye salmon over a 15 year period. Given that changes in egg size and the number of surviving offspring associated with parental influences are clear examples of intergenerational effects in sockeye salmon, the weight of evidence suggests that migratory stress associated with the parental spawning migration can contribute to an alteration in intergenerational gene flow and offspring size.

Book Quantifying the Impact of Two Native Predators on Juvenile Sockeye Salmon Survival in Lake Washington

Download or read book Quantifying the Impact of Two Native Predators on Juvenile Sockeye Salmon Survival in Lake Washington written by Casey Porter Clark and published by . This book was released on 2017 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the mechanisms regulating population fluctuations, such as births, reproduction, and deaths, remains a persistent question in ecology. Mortality can be incurred at any point during the lifecycle, but mortality rates can be high for juvenile animals in particular. One source of this early life history mortality is via predation. Accurately measuring predation rates requires intensive studies, and is further complicated by variability in habitats and changes in the extent of spatial and temporal overlap between predators and prey. In this study, we examined abundance, spatial distributions and diets of two piscivorous fishes and their predation impact on juvenile salmonids in a well-studied large western lake, Lake Washington. We addressed the following questions: (i) What is the abundance of cutthroat trout and northern pikeminnow in Lake Washington? (ii) At what rates do these predators consume juvenile salmon throughout the year, and how many total juvenile salmon are consumed given the predator population size? Understanding which factors influence predation and the extent of this predatory impact requires temporally and spatially explicit data on the interaction between predators and prey, including both juvenile sockeye salmon and the main alternative prey fish species. To observe these interactions, we used several overlapping sampling types across trophic levels. We used a Chapman-modified population estimation procedure to estimate a cutthroat trout population size of 22,791 ≥300 mm FL and the same procedure to estimate a northern pikeminnow population size of 13,582 ≥300 mm FL. We also used a relative catch method to estimate a northern pikeminnow population size of 112,816 ≥300 mm FL. The magnitude of predation on juvenile salmon and other prey fishes varied considerably among months and between cutthroat trout and northern pikeminnow, between small and large size classes of each predator species, and between years. In 2015, predation mortality of lake entry 2015 (sub-yearling) sockeye salmon was 20% of fry production in that year, and predation losses of lake entry 2014 (yearling) sockeye were 56% of pre-smolt production. In 2016, mortality of lake entry 2016 (sub-yearling) sockeye was 44% of fry production, and predation losses of lake entry 2014 sockeye were 473% of pre-smolt production of that year. Our work shows that the current predation rate is high enough and these predator populations are of sufficient size that predation is a significant source of mortality for juvenile sockeye and Chinook salmon in this system. This work highlights a scenario of combined physical and biological factors that influence mortality in juvenile fish, and can potentially inform the potential for predation mortality in other lake systems.

Book Sockeye Salmon Oncorhynchus Nerka

    Sockeye Salmon Oncorhynchus Nerka

    Book Details:
  • Author : Canada. Department of Fisheries and Oceans
  • Publisher : Fisheries and Oceans, Information and Publications Branch
  • Release : 1987
  • ISBN :
  • Pages : 508 pages

Download or read book Sockeye Salmon Oncorhynchus Nerka written by Canada. Department of Fisheries and Oceans and published by Fisheries and Oceans, Information and Publications Branch. This book was released on 1987 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-day symposium was organized by the Department of Fisheries and Oceans and convened at Nanaimo, British Columbia in November 1985. Advice on subject matter and participation came from an external committee of senior scientists and administrators in contributing agencies in Canada, Japan, the United States, and the Union of Soviet Socialist Republics. The papers included in the proceedings deal with sockeye biology and stock management. Papers on sockeye biology are divided into those concerned primarily with life history strategies and enhancement and development. Papers dealing with management are divided into the tools of management and management of some principal stocks.

Book Sport Fishery Abstracts

Download or read book Sport Fishery Abstracts written by and published by . This book was released on 1991 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Technical Report

Download or read book Technical Report written by and published by . This book was released on 1997 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Control of Fish Migration

Download or read book The Control of Fish Migration written by R.J.F. Smith and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fish migration is important and spectacular. Migratory fish gather energy in one portion of the environment and transport it to other areas, where it often becomes available to humans or to other elements in the ecosystem. Migration brings fish into situations that allow easy harvest as they concentrate along migration routes. Their journeys also make them vulnerable to human intereference at critical points along their route. Salmon, for example, may harvest plankton in the open ocean and transport that food energy to coastal and inland regions, where it is captured by fisheries or deposited in inland streams and utilized by the flora and fauna of the region. These salmon are able to complete journeys of thousands of kilometers from their natal streams to oceanic feeding grounds and back to the same home streams, an accomplishment that strains our credi bili ty . We now understand some of the timing and guiding stimuli used in these migrations, and mechanisms can be logically proposed, on the basis of the established abilities of fishes, to account for the unexplained portions of the migrations. There is no single factor guiding these fish. Instead, they are dependent on the presence in their environment of a great variety of appropriate orienting and timing stimuli. These stimuli are vulnerable to human interference. The more widespread and easily available the information on these requirements, the more readily fish can be protected from such interference.