Prevalence and recurrence of escaped farmed Atlantic salmon (Salmo salar) in eastern North American rivers

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 ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
North American ◽  
Temporal Trends ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
In The Wild ◽  
Farmed Atlantic Salmon ◽  
Comprehensive Compilation

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.

Flavour and off-flavour in wild and farmed atlantic salmon from locations around northern ireland

1995 ◽  
Vol 31 (11) ◽  
pp. 259-264 ◽  
Author(s):  
L. J. Farmer ◽  
J. M. McConnell ◽  
T. D. J. Hagan ◽  
D. B. Harper
Keyword(s):  
Northern Ireland ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Scientific Basis ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Short Period ◽  
Profiling Techniques ◽  
Farmed Atlantic Salmon

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.

scholarly journals Escape history and proportion of farmed Atlantic salmon Salmo salar on the coast and in an adjacent salmon fjord in Norway

2020 ◽  
Vol 12 ◽  
pp. 371-383
Author(s):  
T Aronsen ◽  
EM Ulvan ◽  
TF Næsje ◽  
P Fiske
Keyword(s):  
Atlantic Salmon ◽  
Body Length ◽  
Salmo Salar ◽  
Coastal Waters ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Significant Difference ◽  
In The Wild ◽  
The Mean ◽  
Farmed Atlantic Salmon

To gain more knowledge about escaped farmed salmon Salmo salar in the wild, we investigated the proportion of escapees, body length at escape, proportion escaped as smolts/post-smolts (≤300 mm) and number of winters in the wild (winter zones in the growth pattern in the scale samples) in catches on the Norwegian coast and in an adjacent fjord from 2013 to 2017. The mean proportion of escapees was higher on the coast (26%) than in the fjord (4%), and escapees caught on the coast had a slightly larger mean body length at escape (607 mm) than in the fjord (557 mm). However, the mean proportion escaped as smolts/post-smolts did not differ significantly between the coast (8%) and the fjord (11%). There was also no significant difference in the mean proportion of farmed salmon with 1 or more winter zones after escape (50% on the coast and 56% in the fjord). The proportions of escapees with 1, 2, 3 or 4 winter zones after escape were 28, 20, 2 and 0.4% in catches on the coast and 30, 21 and 4% in catches in the fjord, respectively. This study found that the proportion of escapees was considerably higher in coastal waters than in the fjord. Escapees consisted of farmed salmon from several escape events over several years, and approximately 50% of the escapees had one or more winter zones after escape. Thus, escaped farmed salmon may pose a threat to wild salmon populations for several years after the escape event.

scholarly journals Monitoring the incidence of escaped farmed Atlantic salmon, Salmo salar L., in rivers and fisheries of the United Kingdom and Ireland: current progress and recommendations for future programmes

2006 ◽  
Vol 63 (7) ◽  
pp. 1201-1210 ◽  
Author(s):  
Alan M. Walker ◽  
Malcolm C.M. Beveridge ◽  
Walter Crozier ◽  
Niall Ó Maoiléidigh ◽  
Nigel Milner
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Best Practice ◽  
British Isles ◽  
Fish Farms ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
The United Kingdom ◽  
Farmed Atlantic Salmon ◽  
Farming Industry

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.

Performance of farmed, hybrid, and wild Atlantic salmon (Salmo salar) families in a natural river environment

2012 ◽  
Vol 69 (12) ◽  
pp. 1994-2006 ◽  
Author(s):  
Øystein Skaala ◽  
Kevin A. Glover ◽  
Bjørn T. Barlaup ◽  
Terje Svåsand ◽  
Francois Besnier ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Growth Rates ◽  
Egg Size ◽  
Relative Survival ◽  
Hybrid Progeny ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Sib Families

Survival, growth, and diet were compared for farmed, hybrid, and wild Atlantic salmon (Salmo salar) families from the eyed egg to the smolt stage in River Guddalselva, Hardangerfjord, Norway. All individuals that survived until the smolt stage were captured in a Wolf trap and identified to one of the 69 experimental families using microsatellite markers. Survival of farmed salmon progeny was significantly lower than that of hybrids and wild progeny. However, survival varied considerably, from 0.17% to 6.4%, among farmed families. Egg size had an important influence on survival. Half-sib hybrid families with a farmed mother had higher survival when fathered by wild salmon than by farmed salmon. The overall relative survival of farmed families compared with that of their hybrid half-sib families fell from 0.86 in the second cohort to 0.62 in the last cohort with increasing fish density. Smolts of farmed parents showed significantly higher growth rates than wild and hybrid smolts. The overlap in diet among types of crosses demonstrates competition, and farm and hybrid progeny therefore will reduce the river’s capacity for production of wild salmon.

scholarly journals Does density influence relative growth performance of farm, wild and F 1 hybrid Atlantic salmon in semi-natural and hatchery common garden conditions?

2016 ◽  
Vol 3 (7) ◽  
pp. 160152 ◽  
Author(s):  
Alison C. Harvey ◽  
Gareth Juleff ◽  
Gary R. Carvalho ◽  
Martin I. Taylor ◽  
Monica F. Solberg ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Natural Environment ◽  
Common Garden ◽  
High Density ◽  
Lower Growth ◽  
Relative Growth ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
In The Wild

The conditions encountered by Atlantic salmon, Salmo salar L., in aquaculture are markedly different from the natural environment. Typically, farmed salmon experience much higher densities than wild individuals, and may therefore have adapted to living in high densities. Previous studies have demonstrated that farmed salmon typically outgrow wild salmon by large ratios in the hatchery, but these differences are much less pronounced in the wild. Such divergence in growth may be explained partly by the offspring of wild salmon experiencing higher stress and thus lower growth when compared under high-density farming conditions. Here, growth of farmed, wild and F 1 hybrid salmon was studied at contrasting densities within a hatchery and semi-natural environment. Farmed salmon significantly outgrew hybrid and wild salmon in all treatments. Importantly, however, the reaction norms were similar across treatments for all groups. Thus, this study was unable to find evidence that the offspring of farmed salmon have adapted more readily to higher fish densities than wild salmon as a result of domestication. It is suggested that the substantially higher growth rate of farmed salmon observed in the hatchery compared with wild individuals may not solely be caused by differences in their ability to grow in high-density hatchery scenarios.

Large-Scale Escapes of Farmed Atlantic Salmon (Salmo salar) into Norwegian Rivers Threaten Natural Populations

1991 ◽  
Vol 48 (3) ◽  
pp. 426-428 ◽  
Author(s):  
D. Gausen ◽  
V. Moen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Large Scale ◽  
Natural Populations ◽  
Genetic Introgression ◽  
Fish Farms ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar ◽  
Farmed Atlantic Salmon ◽  
And Behavior

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.

scholarly journals An Update on the Content of Fatty Acids, Dioxins, PCBs and Heavy Metals in Farmed, Escaped and Wild Atlantic Salmon (Salmo salar L.) in Norway

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1901
Author(s):  
Ida-Johanne Jensen ◽  
Karl-Erik Eilertsen ◽  
Carina Helen Almli Otnæs ◽  
Hanne K. Mæhre ◽  
Edel Oddny Elvevoll
Keyword(s):  
Heavy Metals ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Omega 3 ◽  
Farmed Fish ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Atlantic Salmon Salmo Salar

In this paper, we present updated data on proximate composition, amino acid, and fatty acid composition, as well as concentrations of dioxins, polychlorinated biphenyls (PCBs), and selected heavy metals, in fillets from farmed (n = 20), escaped (n = 17), and wild (n = 23) Atlantic salmon (Salmo salar L.). The concentrations of dioxins (0.53 ± 0.12 pg toxic equivalents (TEQ)/g), dioxin-like PCBs (0.95 ± 0.48 pg TEQ/g), mercury (56.3 ± 12.9 µg/kg) and arsenic (2.56 ± 0.87 mg/kg) were three times higher in wild compared to farmed salmon, but all well below EU-uniform maximum levels for contaminants in food. The six ICES (International Council for the Exploration of the Sea) PCBs concentrations (5.09 ± 0.83 ng/g) in wild salmon were higher than in the farmed fish (3.34 ± 0.46 ng/g). The protein content was slightly higher in wild salmon (16%) compared to the farmed fish (15%), and the amount of essential amino acids were similar. The fat content of farmed salmon (18%) was three times that of the wild fish, and the proportion of marine long-chain omega-3 fatty acids was a substantially lower (8.9 vs. 24.1%). The omega-6 to omega-3 fatty acid ratio was higher in farmed than wild salmon (0.7 vs. 0.05). Both farmed and wild Atlantic salmon are still valuable sources of eicosapentaenoic acid and docosahexaenoic acid. One 150 g portion per week will contribute to more (2.1 g and 1.8 g) than the recommended weekly intake for adults.

Effects of acidic pH on wild, farmed, and F1 hybrid Atlantic salmon (Salmo salar) parr

2018 ◽  
Vol 75 (1) ◽  
pp. 116-120
Author(s):  
Lynn Lush ◽  
Isabel Costa ◽  
Kimberly Marshall ◽  
Juan Carlos Pérez-Casanova ◽  
Rénald Belley ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Common Garden ◽  
F1 Hybrids ◽  
Acidic Ph ◽  
F1 Hybrid ◽  
Atlantic Salmon Salmo Salar ◽  
In The Wild ◽  
Acidic Waters ◽  
Farmed Atlantic Salmon

Farmed escapees have the potential to introduce novel genes to wild salmon and alter locally adapted populations. We tested whether the acidic conditions found in rivers on Newfoundland’s south coast might differentially impact offspring of farmed Atlantic salmon (Salmo salar) in comparison to wild populations. We performed crosses with wild and farmed parents to obtain wild (W♂ × W♀), farmed (F♂ × F♀), and F1 hybrid (W♂ × F♀, F♂ × W♀) parr and conducted a common garden experiment at neutral or acidic pH. No differences were observed between pure wild crosses and F1 hybrids, suggesting that acidic waters do not differentially affect survival, growth, condition factor, and Na+/K+-ATPase activity of F1 hybrids. Trends in mortality show that pure farmed parr had lower survival than pure wild and F1 hybrids in low pH. Considering that production of F1 hybrids rather than pure farmed offspring is the most likely outcome in the wild, pure farmed parr survival may have little bearing on the prediction of genetic risks of farmed–wild interactions. There is no evidence to indicate that the survival of the F1 generation in acidic waters acts as a potential barrier against introgression.

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