Salmonid Spawning Habitat in Rivers

Salmonid Spawning Habitat in Rivers

Author: David A. Sear

Publisher:

Published: 2008

Total Pages: 396

ISBN-13:

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"Proceedings of the Symposium 'Physical Factors Affecting Salmon Spawning and Egg Survival to Emergence: Integrating Science and Remediation Management' Held in Quebec City, Quebec, Canada, August 13-14, 2003."


Wild Salmonids in the Urbanizing Pacific Northwest

Wild Salmonids in the Urbanizing Pacific Northwest

Author: J. Alan Yeakley

Publisher: Springer Science & Business Media

Published: 2013-11-20

Total Pages: 270

ISBN-13: 1461488184

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Wild salmon, trout, char, grayling, and whitefish (collectively salmonids) have been a significant local food and cultural resource for Pacific Northwest peoples for millennia. The location, size, and distribution of urban areas along streams, rivers, estuaries, and coasts directly and indirectly alter and degrade wild salmonid populations and their habitats. Although urban and exurban areas typically cover a smaller fraction of the landscape than other land uses combined, they have profound consequences for local ecosystems, aquatic and terrestrial populations, and water quality and quantity.​


Salmon Without Rivers

Salmon Without Rivers

Author: Jim Lichatowich

Publisher:

Published: 1999-08

Total Pages: 346

ISBN-13:

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"Fundamentally, the salmon's decline has been the consequence of a vision based on flawed assumptions and unchallenged myths.... We assumed we could control the biological productivity of salmon and 'improve' upon natural processes that we didn't even try to understand. We assumed we could have salmon without rivers." --from the introduction From a mountain top where an eagle carries a salmon carcass to feed its young to the distant oceanic waters of the California current and the Alaskan Gyre, salmon have penetrated the Northwest to an extent unmatched by any other animal. Since the turn of the twentieth century, the natural productivity of salmon in Oregon, Washington, California, and Idaho has declined by eighty percent. The decline of Pacific salmon to the brink of extinction is a clear sign of serious problems in the region. In Salmon Without Rivers, fisheries biologist Jim Lichatowich offers an eye-opening look at the roots and evolution of the salmon crisis in the Pacific Northwest. He describes the multitude of factors over the past century and a half that have led to the salmon's decline, and examines in depth the abject failure of restoration efforts that have focused almost exclusively on hatcheries to return salmon stocks to healthy levels without addressing the underlying causes of the decline. The book: describes the evolutionary history of the salmon along with the geologic history of the Pacific Northwest over the past 40 million years considers the indigenous cultures of the region, and the emergence of salmon-based economies that survived for thousands of years examines the rapid transformation of the region following the arrival of Europeans presents the history of efforts to protect and restore the salmon offers a critical assessment of why restoration efforts have failed Throughout, Lichatowich argues that the dominant worldview of our society -- a worldview that denies connections between humans and the natural world -- has created the conflict and controversy that characterize the recent history of salmon; unless that worldview is challenged and changed, there is little hope for recovery. Salmon Without Rivers exposes the myths that have guided recent human-salmon interactions. It clearly explains the difficult choices facing the citizens of the region, and provides unique insight into one of the most tragic chapters in our nation's environmental history.


Ecology of Atlantic Salmon and Brown Trout

Ecology of Atlantic Salmon and Brown Trout

Author: Bror Jonsson

Publisher: Springer Science & Business Media

Published: 2011-05-03

Total Pages: 720

ISBN-13: 9400711891

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Destruction of habitat is the major cause for loss of biodiversity including variation in life history and habitat ecology. Each species and population adapts to its environment, adaptations visible in morphology, ecology, behaviour, physiology and genetics. Here, the authors present the population ecology of Atlantic salmon and brown trout and how it is influenced by the environment in terms of growth, migration, spawning and recruitment. Salmonids appeared as freshwater fish some 50 million years ago. Atlantic salmon and brown trout evolved in the Atlantic basin, Atlantic salmon in North America and Europe, brown trout in Europe, Northern Africa and Western Asia. The species live in small streams as well as large rivers, lakes, estuaries, coastal seas and oceans, with brown trout better adapted to small streams and less well adapted to feeding in the ocean than Atlantic salmon. Smolt and adult sizes and longevity are constrained by habitat conditions of populations spawning in small streams. Feeding, wintering and spawning opportunities influence migratory versus resident lifestyles, while the growth rate influences egg size and number, age at maturity, reproductive success and longevity. Further, early experiences influence later performance. For instance, juvenile behaviour influences adult homing, competition for spawning habitat, partner finding and predator avoidance. The abundance of wild Atlantic salmon populations has declined in recent years; climate change and escaped farmed salmon are major threats. The climate influences through changes in temperature and flow, while escaped farmed salmon do so through ecological competition, interbreeding and the spreading of contagious diseases. The authors pinpoint essential problems and offer suggestions as to how they can be reduced. In this context, population enhancement, habitat restoration and management are also discussed. The text closes with a presentation of what the authors view as major scientific challenges in ecological research on these species.