نتایج جستجو برای: caspian salmon
تعداد نتایج: 15460 فیلتر نتایج به سال:
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 ...
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 ...
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...
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 ...
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...
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...
Introduction Perhaps, the most exciting equine discovery of the 20th century was that the Caspian is not a pony, but an ancient breed of miniature horse, previously believed to have been extinct for over a thousand years. These animals native of the areas around the Elborz Mountains and Caspian Sea in Iran, are extremely rare and were rescued from extinction in 1965 by an American L.FIROUSE [11...
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...
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...
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