Cultured Atlantic salmon (Salmo salar L.) may be introduced into natural systems intentionally or accidentally. As smolts or post-smolts, they move to the feeding areas of wild salmon in the North Atlantic Ocean. As maturing fish, they return to the area of release and enter rivers to spawn. Lack of juvenile river experience is the prime reason why cultured salmon often enter fresh water later ...

Many fish that are exposed to a threat release disturbance cues, which are chemicals that alert conspecifics to the presence of the threat. The release of disturbance cues has been well demonstrated in various species of laboratory-reared fish. Migratory fish species often exhibit increased cortisol levels and are exposed to numerous stressors during their migrations, which could trigger the re...

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...

Iran contributes to the stock enhancement of several economically valuable fish species, including the Caspian salmon, S. trutta caspius, by producing and releasing millions of fingerlings into the sea. This work was conducted to determine the production costs of the Caspian salmon fingerlings in the years 2002 and 2003. For this purpose, a questionnaire was prepared and filled in by an expert ...

The migration of Pacific salmon is an important part of functioning freshwater ecosystems, but as populations have decreased and ecological conditions have changed, so have migration patterns. Understanding how the environment, and human impacts, change salmon migration behavior requires observing migration at small temporal and spatial scales across large geographic areas. Studying these detai...

The author details the connection between disease outbreaks in salmonid fish and imports of salmonid eggs into Japan since the 1950s. The following diseases and species are involved: -infectious pancreatic necrosis in rainbow trout (Oncorhynchus mykiss) -infectious haematopoietic necrosis in sockeye ( of 'kokanee') salmon (O. nerka) and masu salmon (O. masu) -cold water disease, erythrocyte inc...

This data article reports the chemical properties (moisture, pH, salinity, and soluble solid content) and colors of fermenting materials in salmon fish sauce products. The fish sauce was produced by mixing salt with differing proportions of raw salmon materials and fermenting for three months; the salmon materials comprised flesh, viscera, an inedible portion, and soft roe. Chemical properties ...

Salmon carcasses were recorded during October December along spawning streams in 3 study areas: 1 upper Shee Water, R. Tay system (2000 & 2001); 2. Upper Clunie Water, Aberdeenshire Dee system (2000 [part of area] and 2001) and 3. Kinlochewe River, R. Ewe system (2001 only). Estimates of numbers of salmon within each study area are based on fish observations, redd counts and counts at fish trap...

Mercury (Hg) is a potent toxin that biomagnifies in aquatic food webs. Large fish generally have higher Hg concentrations than small fish of the same species. However, models predict that fish that grow large faster should have lower Hg concentrations than small, slow-growing fish due to somatic growth dilution (SGD). We examined the relationship between Hg concentrations and growth rate in fis...

Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonid...