scholarly journals Risk assessment of the environmental impact of Norwegian Atlantic salmon farming

2014 ◽  
Vol 72 (3) ◽  
pp. 997-1021 ◽  
Author(s):  
Geir Lasse Taranger ◽  
Ørjan Karlsen ◽  
Raymond John Bannister ◽  
Kevin Alan Glover ◽  
Vivian Husa ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Atlantic Salmon ◽  
Viral Disease ◽  
Organic Load ◽  
Genetic Introgression ◽  
Wild Populations ◽  
Fish Farms ◽  
Marine Research ◽  
Salmon Farming ◽  
Salmon Lice

Abstract Norwegian aquaculture has grown from its pioneering days in the 1970s to be a major industry. It is primarily based on culturing Atlantic salmon and rainbow trout and has the potential to influence the surrounding environment and wild populations. To evaluate these potential hazards, the Institute of Marine Research initiated a risk assessment of Norwegian salmon farming in 2011. This assessment has been repeated annually since. Here, we describe the background, methods and limitations of the risk assessment for the following hazards: genetic introgression of farmed salmon in wild populations, regulatory effects of salmon lice and viral diseases on wild salmonid populations, local and regional impact of nutrients and organic load. The main findings are as follows: (i) 21 of the 34 wild salmon populations investigated indicated moderate-to-high risk for genetic introgression from farmed escaped salmon. (ii) of 109 stations investigated along the Norwegian coast for salmon lice infection, 27 indicated moderate-to-high likelihood of mortality for salmon smolts while 67 stations indicated moderate-to-high mortality of wild sea trout. (iii) Viral disease outbreaks (pancreas disease, infectious pancreatic necrosis, heart and skeletal muscle inflammation, and cardiomyopathy syndrome) in Norwegian salmon farming suggest extensive release of viruses in many areas. However, screening of wild salmonids revealed low to very low prevalence of the causal viruses. (iv) From ∼500 yearly investigations of local organic loading under fish farms, only 2% of them displayed unacceptable conditions in 2013. The risk of eutrophication and organic load beyond the production area of the farm is considered low. Despite several limitations, especially limited monitoring data, this work represents one of the world’s first risk assessment of aquaculture. This has provided the Norwegian government with the basis upon which to take decisions for further development of the Norwegian aquaculture industry.

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 Salmon lice increase the age of returning Atlantic salmon

2014 ◽  
Vol 10 (1) ◽  
pp. 20130896 ◽  
Author(s):  
Knut Wiik Vollset ◽  
Bjørn Torgeir Barlaup ◽  
Helge Skoglund ◽  
Eirik Straume Normann ◽  
Ove Tommy Skilbrei
Keyword(s):  
Atlantic Salmon ◽  
Life History Traits ◽  
Age Distribution ◽  
Wild Populations ◽  
Age At Maturity ◽  
Farmed Fish ◽  
Parasite Abundance ◽  
Salmon Lice ◽  
Global Increase ◽  
Host Parasite

The global increase in the production of domestic farmed fish in open net pens has created concerns about the resilience of wild populations owing to shifts in host–parasite systems in coastal ecosystems. However, little is known about the effects of increased parasite abundance on life-history traits in wild fish populations. Here, we report the results of two separate studies in which 379 779 hatchery-reared Atlantic salmon smolts were treated (or not) against salmon lice, marked and released. Adults were later recaptured, and we specifically tested whether the age distribution of the returning spawners was affected by the treatment. The estimates of parasite-induced mortality were 31.9% and 0.6% in the River Vosso and River Dale stock experiments, respectively. Age of returning salmon was on average higher in treated versus untreated fish. The percentages of fish returning after one winter at sea were 37.5% and 29.9% for the treated and untreated groups, respectively. We conclude that salmon lice increase the age of returning salmon, either by affecting their age at maturity or by disproportionately increasing mortality in fish that mature early.

scholarly journals Predicting the impacts of escaped farmed Atlantic salmon on wild salmon populations

2018 ◽  
Vol 75 (4) ◽  
pp. 506-512 ◽  
Author(s):  
Freya Keyser ◽  
Brendan F. Wringe ◽  
Nicholas W. Jeffery ◽  
J. Brian Dempson ◽  
Steven Duffy ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Genetic Introgression ◽  
Nucleotide Polymorphisms ◽  
Wild Populations ◽  
Northwest Atlantic ◽  
Wild Salmon ◽  
Facility Locations ◽  
Farmed Salmon ◽  
Farmed Atlantic Salmon ◽  
The Impact

The escape of Atlantic salmon (Salmo salar) from aquaculture facilities can result in both negative genetic and ecological interactions with wild populations, yet the ability to predict the associated risk to wild populations has remained elusive. Here we assess the potential of a spatiotemporal database of aquaculture facility locations, production estimates, and escape events to predict the distribution of escaped farmed salmon and genetic impacts on wild populations in the Northwest Atlantic. Industry production data, reported escape events, and in-river detections of escaped farmed salmon were collected from across the Northwest Atlantic. Genetic estimates of impact were obtained using single nucleotide polymorphisms (95 loci) representing aquaculture and wild salmon throughout the region (30 populations, 3048 individuals). Both the number of escaped farmed salmon detected at counting facilities and the magnitude of genetic impacts were positively correlated with a cumulative spatial measure of aquaculture production. Our results suggest that the risk of escapees and genetic introgression from wild–farmed salmon interactions can be assessed using information on farm production characteristics. This represents a first step in predicting the impact of existing cage-based farms on wild Atlantic salmon.

scholarly journals Organophosphate Poisoning of Atlantic Salmon in Connection with Treatment against Salmon Lice

1989 ◽  
Vol 30 (4) ◽  
pp. 385-390
Author(s):  
Tor Einar Horsberg ◽  
Tonje Høy ◽  
Inger Nafstad
Keyword(s):  
Atlantic Salmon ◽  
Organophosphate Poisoning ◽  
Salmon Lice

Effects of salmon lice infection and salmon lice protection on fjord migrating Atlantic salmon and brown trout post-smolts

2007 ◽  
pp. 35-42
Author(s):  
Rolf Sivertsgård ◽  
Eva B. Thorstad ◽  
Finn Økland ◽  
Bengt Finstad ◽  
Pål Arne Bjørn ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Salmon Lice

scholarly journals Salmon lice evasion, susceptibility, retention, and development differ amongst host salmonid species

2017 ◽  
Vol 75 (3) ◽  
pp. 1071-1079 ◽  
Author(s):  
Samantha Bui ◽  
Elina Halttunen ◽  
Agnes M Mohn ◽  
Tone Vågseth ◽  
Frode Oppedal
Keyword(s):  
Atlantic Salmon ◽  
Chinook Salmon ◽  
Salmo Trutta ◽  
Parasite Development ◽  
Lepeophtheirus Salmonis ◽  
Sea Trout ◽  
Salmon Lice ◽  
Salmonid Species ◽  
Host Parasite ◽  
Temporal Overlap

Abstract With different ecological characteristics amongst salmonid species, their response to parasitic infestation is likely to vary according to their spatial and temporal overlap with the parasite. This study investigated the host–parasite interactions amongst three species of salmonids and the ectoparasitic salmon louse, Lepeophtheirus salmonis. To determine any variation in infestation parameters amongst salmonids, single population groups of Atlantic salmon (Salmo salar), chinook salmon (Onchorhynchus tshawytscha), and previously-infested and naïve sea trout (Salmo trutta) were exposed to a controlled infestation challenge. We found that chinook salmon and both sea trout groups were more susceptible to acquiring lice than Atlantic salmon. Behavioural responses during infestation were more pronounced in Atlantic and chinook salmon. Parasite development was similar in lice attached to Atlantic salmon and sea trout, but hindered on chinook salmon. At 16 days post-infestation, chinook salmon had reduced lice loads to the same level as Atlantic salmon, whilst sea trout retained their lice. These results demonstrate differences in interactions with L. salmonis amongst these species, and highlight the vulnerability of sea trout to infestation.

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