Absence of Nematodes in Farmed Atlantic Salmon (Salmo salar L.) in Norway

2003 ◽  
Vol 66 (1) ◽  
pp. 122-124 ◽  
Author(s):  
BJØRN TORE LUNESTAD

In the present study, a total of 1,180 samples of muscle or viscera from Norwegian-farmed salmon (Salmo salar L.) were examined for the presence of nematode larvae. The samples represented all salmon-producing counties in Norway. The method applied was based on the degradation of fish soft tissue in an acidified pepsin enzyme solution. None of the samples examined in this study contained nematodes.

2006 ◽  
Vol 63 (7) ◽  
pp. 1201-1210 ◽  
Author(s):  
Alan M. Walker ◽  
Malcolm C.M. Beveridge ◽  
Walter Crozier ◽  
Niall Ó Maoiléidigh ◽  
Nigel Milner

Abstract An inevitable consequence of the development of the Atlantic salmon, Salmo salar L., farming industry in coastal waters of the British Isles has been the loss of farmed salmon to the wild, their occurrence in inshore waters and rivers, and their appearance in coastal and freshwater fisheries. Monitoring programmes have been developed throughout the British Isles, variously using scientific sampling, catch records from coastal or freshwater fisheries or both, and scientific sampling of catches from in-river traps. We compare the results of these monitoring programmes with regional production and the numbers of escapees reported from marine fish farms. We also consider the effectiveness of the programmes for assessing the prevalence of farmed salmon that escape from marine cages. Finally, we make recommendations for improvements to these programmes and for the development of best practice, including the scientific sampling of in-river spawning stocks through fishery-independent sources, identification of fish origin based on at least two methods, assessment of the degree of incorrect classification, and the timely and accurate reporting of all escapes.


1991 ◽  
Vol 48 (3) ◽  
pp. 426-428 ◽  
Author(s):  
D. Gausen ◽  
V. Moen

We present data on Atlantic salmon (Salmo salar) which show that escaped farmed salmon enter Norwegian rivers in great numbers. Escaped farmed salmon comprised a substantial proportion of the mature salmon present on the spawning grounds in autumn. A potential for large-scale genetic introgression thus exists. The sex ratios, length distributions, and times of ascent of wild and farmed salmon differed significantly, reflecting major variations in biology and behavior. High proportions of farmed salmon (> 20%) were found only in rivers having fish farms situated closer than 20 km from the outlet.


2008 ◽  
Vol 65 (12) ◽  
pp. 2807-2826 ◽  
Author(s):  
Matthew R.J. Morris ◽  
Dylan J. Fraser ◽  
Anthony J. Heggelin ◽  
Frederick G. Whoriskey ◽  
Jonathan W. Carr ◽  
...  

Knowledge of the prevalence of escaped farmed fishes in the wild is an essential first step to assessing the risk resulting from interactions between farmed and wild fishes. This is especially important in eastern North America, where Atlantic salmon ( Salmo salar ) aquaculture occurs near wild Atlantic salmon rivers and where many wild salmon populations are severely depressed. Here, we review the literature on the incidence of escaped farmed salmon in eastern North American rivers, for which there has been no comprehensive compilation to date. Escaped farmed salmon have been found in 54 of 62 (87%) rivers investigated within a 300 km radius of the aquaculture industry since 1984, including 11 rivers that contain endangered salmon populations. Averaged among all investigations, the proportional representation of farmed salmon among adults entering the rivers from the sea was 9.2% (range 0% to 100%). Where data were sufficient to examine temporal trends, farmed salmon proportions varied considerably over time, suggesting that escape events are episodic in nature. We conclude that escaped farmed salmon are sufficiently prevalent in eastern North American rivers to pose a potentially serious risk to the persistence of wild salmon populations, especially in those rivers that are adjacent to existing aquaculture sites.


1995 ◽  
Vol 31 (11) ◽  
pp. 259-264 ◽  
Author(s):  
L. J. Farmer ◽  
J. M. McConnell ◽  
T. D. J. Hagan ◽  
D. B. Harper

Sensory profiling techniques were used to investigate the odour and flavour of Atlantic salmon (Salmo salar) from six sources in order to determine (i) whether there was any scientific basis for reports of off-flavours in salmon from certain sources and (ii) whether farmed and wild salmon differed in terms of flavour attributes. There were no consistent differences in odour or flavour between sea-caught wild salmon and farmed salmon. However, river-caught wild salmon showed enhanced ‘earthy’ flavour and odour; GC-odour assessment studies have indicated that 2-methylisoborneol and geosmin contribute to these attributes. For a short period, wild river salmon from one source also suffered from a manure-like off-flavour which has been shown to be due to the presence of skatole. The source of this compound remains uncertain.


1991 ◽  
Vol 48 (3) ◽  
pp. 429-433 ◽  
Author(s):  
Harald Lura ◽  
Harald Saegrov

A method of separating eggs and alevins from wild and farmed Atlantic salmon (Salmo salar) is described, using high-performance liquid chromatography (HPLC) to trace optical isomers of astaxanthin commonly occurring in the diet of both wild and farmed salmon. The proportions of isomers in eggs and alevins of farmed salmon, fed synthetic astaxanthin, differ highly from those of wild fish. The method can be used as a tool to determine the spawning success of escaped farmed female Atlantic salmon.


Sign in / Sign up

Export Citation Format

Share Document