scholarly journals Estimating the temporal overlap between post-smolt migration of Atlantic salmon and salmon lice infestation pressure from fish farms

2016 ◽  
Vol 8 ◽  
pp. 511-525 ◽  
Author(s):  
KW Vollset ◽  
BT Barlaup ◽  
S Mahlum ◽  
PA Bjørn ◽  
OT Skilbrei
Keyword(s):  
Atlantic Salmon ◽  
Fish Farms ◽  
Salmon Lice ◽  
Temporal Overlap

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.

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.

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

Thermal delousing in anaesthetised small Atlantic salmon (Salmo salar) post-smolts: A case study showing the viability of anaesthesia prior to delousing for improved welfare during treatment for salmon lice

2021 ◽  
Vol 30 (2) ◽  
pp. 117-120
Author(s):  
O Folkedal ◽  
SO Utskot ◽  
J Nilsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Experimental Research ◽  
Acute Stress ◽  
Small Scale ◽  
Lepeophtheirus Salmonis ◽  
Salmon Lice ◽  
Sequence Of Events ◽  
Present Case Study

Delousing treatment for salmon sea lice (Lepeophtheirus salmonis) is considered a significant welfare concern in farming of Atlantic salmon ( Salmo salar), where both industry and legislative bodies prompt for better methods. Currently, the most common method is thermal delousing, where fish are crowded, pumped into a vessel and exposed to ∼28–34°C for ∼30 s. Physical collisions occurring as a result of a loss of behavioural control lead to acute stress. Crowding triggers vigorous escape behaviour as salmon respond not only to treatment but also to being channeled to and from the treatment zone. A sequence of events considered to cause mortality and poor welfare. The present case study was motivated by an urgent need for delousing in groups of small salmon post-smolts in experimental research. For this purpose, a simple, small-scale system for thermal delousing was constructed, including anaesthesia to alleviate behavioural responses. The anaesthetised fish showed little behavioural response to thermal treatment, strong appetite within hours, and negligible mortality. The described method is regarded as a welfare-friendly alternative to industrial delousing in smaller fish groups, for example, in experimental research. We would encourage detailed research aimed towards gaining a deeper under-standing of the welfare effects of anaesthesia prior to treatment for delousing.

scholarly journals Parasite induced mortality is context dependent in Atlantic salmon: insights from an individual-based model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Knut Wiik Vollset
Keyword(s):  
Atlantic Salmon ◽  
Environmental Gradients ◽  
Population Level ◽  
Relative Effect ◽  
Host Population ◽  
Sea Lice ◽  
Fish Farms ◽  
Individual Based Model ◽  
Parasite Infestation ◽  
The Impact

AbstractAn individual-based model was parameterized to explore the impact of a crustacean ectoparasite (sea louse, Lepeophtheirus salmonis & Caligus spp.) on migrating Atlantic salmon smolt. The model explores how environmental and intrinsic factors can modulate the effect of sea lice on survival, growth and maturation of Atlantic salmon at sea. Relative to other effects, the parasite infestation pressure from fish farms and the encounter process emerge as the most important parameters. Although small variations in parasite-induced mortality may be masked by variable environmental effects, episodes of high infestation pressure from fish farms should be observable in wild populations of Atlantic salmon if laboratory studies accurately reflect the physiological effects of sea lice. Increases in temperature in the model negatively influenced fish survival by affecting the development time of the parasite at a rate that was not compensated for by the growth of the host. Discharge from rivers was parameterized to increase migration speed and influenced parasite induced mortality by decreasing time spent in areas with increased infestation pressure. Initial size and growth of the host was inversely related to the impact of the parasite because of size-dependent parasite-induced mortality in the early phase of migration. Overall, the model illustrates how environmental factors modulate effects on the host population by impacting either the parasite load or the relative effect of the parasite. The results suggest that linking population-level effects to parasite infestation pressure across climatic and environmental gradients may be challenging without correctly accounting for these effects.

scholarly journals Near- and far-field dispersal modelling of organic waste from Atlantic salmon aquaculture in fjord systems

2016 ◽  
Vol 73 (9) ◽  
pp. 2408-2419 ◽  
Author(s):  
Raymond J. Bannister ◽  
Ingrid A. Johnsen ◽  
Pia K. Hansen ◽  
Tina Kutti ◽  
Lars Asplin
Keyword(s):  
Atlantic Salmon ◽  
Organic Waste ◽  
Dispersion Model ◽  
Near Field ◽  
Predictive Modelling ◽  
Production Cycle ◽  
Far Field ◽  
Fish Farms ◽  
Salmon Aquaculture ◽  
Tracking Model

Abstract The ability to achieve environmentally sustainable Atlantic salmon aquaculture in coastal fjord ecosystems is currently constrained by our limited knowledge of the regional interactions and fate of organic effluents on benthic ecosystems. A first step in addressing this limitation is to establish predictive modelling tools to better understand local and regional dispersion of organic effluents in the wider ecosystem. By combining settling velocity of faecal waste from different sizes of Atlantic salmon, a three-dimensional hydrodynamic model coupled with a particle tracking model and farm management data, this study presents a first-generation generic near- and far-field effluent dispersion model to predict the spread of particulate organic waste into fjord ecosystems. Simulations predict that >75% of organic effluents are dispersed to near-field sites (<500 m from the release point), while a small proportion of particulate organic effluents (up to 2.7%) are dispersed to far-field sites (>2 km). These simulations indicate that organic effluents from fish farms may be dispersed over large areas of fjord systems. The input of measured “mass fractions” settling velocities of faecal waste from different sizes of Atlantic salmon ensured that modelled predictions of near and far-field dispersion of organic material over a production cycle were in the range of observed POM fluxes.

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.

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