نتایج جستجو برای: salmon patch

تعداد نتایج: 53543  

Journal: :Environmental science & technology 2006
Susan D Shaw Diane Brenner Michelle L Berger David O Carpenter Chia-Swee Hong Kurunthachalam Kannan

Farmed Atlantic salmon (Salmo salar) from Maine and eastern Canada, wild Alaskan Chinook salmon (Oncorhynchus tshawytscha), and organically farmed Norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (PCBs), dioxin-like PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-furans (PCDFs), and chlorinated pesticides. PCDD and PCDF congeners were not detected ...

2008
Yajie Liu Rashid Sumaila

Salmon aquaculture generates good output (i.e., salmon) and bad output (e.g., pollution). A joint production function approach is applied to model both outputs simultaneously. Two environmental production technologies are specified, namely, regulated and unregulated technologies. Two production functions with different mapping rules are applied. Pollution abatement costs are estimated based on ...

Journal: :PLoS Biology 2008
Jennifer S Ford Ransom A Myers†

Since the late 1980s, wild salmon catch and abundance have declined dramatically in the North Atlantic and in much of the northeastern Pacific south of Alaska. In these areas, there has been a concomitant increase in the production of farmed salmon. Previous studies have shown negative impacts on wild salmonids, but these results have been difficult to translate into predictions of change in wi...

Journal: :Proceedings. Biological sciences 2009
Martin Krkosek Alexandra Morton John P Volpe Mark A Lewis

The ecological impact of parasite transmission from fish farms is probably mediated by the migration of wild fishes, which determines the period of exposure to parasites. For Pacific salmon and the parasitic sea louse, Lepeophtheirus salmonis, analysis of the exposure period may resolve conflicting observations of epizootic mortality in field studies and parasite rejection in experiments. This ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2006
Ray Hilborn

C oncerns have been raised about the impact of farmed fish on wild fish through a range of mechanisms including disease and the impact of fish that escape from farms (1). Although Alaska has banned salmon farming and Washington has developed only a very small industry, British Columbia, with an extensive network of protected inlets, has developed a very large salmon-farming industry, now consid...

2008
Dylan J Fraser Adam M Cook James D Eddington Paul Bentzen Jeffrey A Hutchings

Interbreeding between artificially-selected and wild organisms can have negative fitness consequences for the latter. In the Northwest Atlantic, farmed Atlantic salmon recurrently escape into the wild and enter rivers where small, declining populations of wild salmon breed. Most farmed salmon in the region derive from an ancestral source population that occupies a nonacidified river (pH 6.0-6.5...

In this paper, we propose a new compact quasi-fractal shaped microstrip antenna that consists of a hexagonal patch as the main radiator and a complementary stacked patch as the parasitic element. The overall surface of the proposed quasi-fractal patch is about 55% lower than the conventional hexagonal patch. Using of stacked technique, the gain reduction of compression technique is almost compe...

2012
Taal Levi Chris T. Darimont Misty MacDuffee Marc Mangel Paul Paquet Christopher C. Wilmers

Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon prov...

2004
Scott M. Gende Thomas P. Quinn Ray Hilborn Andrew P. Hendry Bobette Dickerson

Pacific salmon return to spawn in thousands of streams across the Pacific Rim, from large rivers to tiny headwater streams. Once on the spawning grounds, salmon undergo dramatic biochemical changes as they metabolize stored lipid and protein reserves; at stream entrance, they will contain up to 85% more lipid and 40% more protein than at their senescent death a week or two later. Foraging brown...

2004
C. E. Wilkinson M. D. Hocking T. E Reimchen

Throughout forested watersheds bordering the North Pacific, anadromous salmon (Oncorhynchus spp. ) are transferred into coastal forests by numerous predators and scavengers with remnants providing an important nutrient subsidy to riparian zones. The contribution of these nutrients to mosses and liverworts, which are the dominant ground cover of coastal forests, has not been investigated. We exa...

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