scholarly journals Descriptive multi-agent epidemiology via molecular screening on Atlantic salmon farms in the northeast Pacific Ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew W. Bateman ◽  
Angela D. Schulze ◽  
Karia H. Kaukinen ◽  
Amy Tabata ◽  
Gideon Mordecai ◽  
...  

AbstractRapid expansion of salmon aquaculture has resulted in high-density populations that host diverse infectious agents, for which surveillance and monitoring are critical to disease management. Screening can reveal infection diversity from which disease arises, differential patterns of infection in live and dead fish that are difficult to collect in wild populations, and potential risks associated with agent transmission between wild and farmed hosts. We report results from a multi-year infectious-agent screening program of farmed salmon in British Columbia, Canada, using quantitative PCR to assess presence and load of 58 infective agents (viruses, bacteria, and eukaryotes) in 2931 Atlantic salmon (Salmo salar). Our analysis reveals temporal trends, agent correlations within hosts, and agent-associated mortality signatures. Multiple agents, most notably Tenacibaculum maritimum, were elevated in dead and dying salmon. We also report detections of agents only recently shown to infect farmed salmon in BC (Atlantic salmon calicivirus, Cutthroat trout virus-2), detection in freshwater hatcheries of two marine agents (Kudoa thyrsites and Tenacibaculum maritimum), and detection in the ocean of a freshwater agent (Flavobacterium psychrophilum). Our results provide information for farm managers, regulators, and conservationists, and enable further work to explore patterns of multi-agent infection and farm/wild transmission risk.

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.


2006 ◽  
Vol 63 (7) ◽  
pp. 1263-1268 ◽  
Author(s):  
Jonathan W. Carr ◽  
Frederick G. Whoriskey

Abstract The escape of juvenile Atlantic salmon from freshwater hatcheries supplying the salmon farming industry may lead to interactions between wild and farmed fish. The scale of this problem, however, has not been examined in detail. We monitored temporal trends in the abundance of escaped juvenile farmed salmon in the Magaguadavic River and Chamcook Stream for several years. In addition, in 2004 we assessed more than 90% of the commercial hatcheries producing salmon smolts located next to freshwater streams in New Brunswick. Escaped juvenile fish were recorded in 75% of the streams electrofished close to hatcheries. Numbers varied by site and year. However, escaped juvenile salmon were found every year at sites near hatcheries in the Magaguadavic River and Chamcook Stream. In the Magaguadavic River, juvenile escapees outnumbered wild salmon parr in most years. These results highlight the need for implementation of a containment strategy for freshwater hatcheries to reduce escapes.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 414
Author(s):  
Joseph P. Nowlan ◽  
Scott R. Britney ◽  
John S. Lumsden ◽  
Spencer Russell

Tenacibaculum are frequently detected from fish with tenacibaculosis at aquaculture sites; however, information on the ecology of these bacteria is sparse. Quantitative-PCR assays were used to detect T. maritimum and T. dicentrarchi at commercial Atlantic salmon (Salmo salar) netpen sites throughout several tenacibaculosis outbreaks. T. dicentrarchi and T. maritimum were identified in live fish, dead fish, other organisms associated with netpens, water samples and on inanimate substrates, which indicates a ubiquitous distribution around stocked netpen sites. Before an outbreak, T. dicentrarchi was found throughout the environment and from fish, and T. maritimum was infrequently identified. During an outbreak, increases in the bacterial load in were recorded and no differences were recorded after an outbreak supporting the observed recrudescence of mouthrot. More bacteria were recorded in the summer months, with more mortality events and antibiotic treatments, indicating that seasonality may influence tenacibaculosis; however, outbreaks occurred in both seasons. Relationships were identified between fish mortalities and antimicrobial use to water quality parameters (temperature, salinity, dissolved oxygen) (p < 0.05), but with low R2 values (<0.25), other variables are also involved. Furthermore, Tenacibaculum species appear to have a ubiquitous spatial and temporal distribution around stocked netpen sites, and with the potential to induce disease in Atlantic salmon, continued research is needed.


2018 ◽  
Vol 31 ◽  
pp. 31
Author(s):  
Per Gunnar Fjelldal ◽  
Monica F. Solberg ◽  
Kevin A. Glover ◽  
Ole Folkedal ◽  
Jonatan Nilsson ◽  
...  

The production of salmonids in sea-cages has been developed for monoculture of the target species. However, we show here for the first time, that wild fish may enter sea-cages used for farming of Atlantic salmon (Salmo salar L.) in Norway, out-grow the mesh size, and thereafter become permanently trapped. Within seven different sea-cages located in western Norway, eight different species of wild fish were identified; European eel (Anguilla anguilla), sea trout (Salmo trutta L.), cod (Gadus morhua), haddock (Melanogrammus aeglefinus), saithe (Pollachius virens), pollack (Pollachius pollachius), hake (Merluccius merluccius) and whiting (Merlangius merlangus). In the two most extreme cases, a 5 × 5 × 7 m cage with 311 farmed salmon (903 g) also contained 542 whiting (79 g), 77 haddock (43 g), and 5 cod (26 g), and a 12 × 12 × 15 m cage with 1695 farmed salmon (559 g) also contained 1196 haddock (35 g), 1115 whiting (31 g), 46 cod (23 g), 23 saithe (48 g), 15 pollock (22 g), 5 sea trout (54 g), and 2 hake (29 g). The present study thus demonstrates that aquaculture cages designed for monoculture may attract and effectively ‘trap’ wild fish. We did not investigate the frequency of this occurrence, and the ecological significance of these observations remains unclear. However, with the ever-increasing number of sea-cages used for global aquaculture, this is clearly a topic for further research.


2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Maria Letizia Fioravanti ◽  
Andrea Gustinelli ◽  
George Rigos ◽  
Kurt Buchmann ◽  
Monica Caffara ◽  
...  

Background The increasing demand for raw or undercooked fish products, supplied by both aquaculture and fisheries, raises concerns about the transmission risk to humans of zoonotic fish parasites. This has led to the current European Union (EU) Regulation No 1276/2011 amending Annex III of Regulation (EC) No 853/2004 and mandating a freezing treatment of such products. Zoonotic parasites, particularly anisakid larvae, have been well documented in wild fish. Data on their presence in European aquaculture products, however, are still scarce, except for Atlantic salmon (Salmo salar), where the zoonotic risk was assessed as negligible, exempting it from freezing treatment. Aim To evaluate the zoonotic Anisakidae parasite risk in European farmed marine fish other than Atlantic salmon. Methods From 2016 to 2018 an observational parasitological survey was undertaken on 6,549 farmed fish including 2,753 gilthead seabream (Sparus aurata), 2,761 European seabass (Dicentrarchus labrax) and 1,035 turbot (Scophthalmus maximus) from 14 farms in Italy, Spain and Greece. Furthermore, 200 rainbow trout (Oncorhynchus mykiss) sea-caged in Denmark, as well as 352 seabream and 290 seabass imported in Italy and Spain from other countries were examined. Fish were subjected to visual inspection and candling. Fresh visceral organs/fillet samples were artificially digested or UV pressed and visually examined for zoonotic anisakid larvae. Results No zoonotic parasites were found in any of the fish investigated. Conclusions The risk linked to zoonotic Anisakidae in the examined fish species from European mariculture appears negligible. This study laid the groundwork for considerations to amend the current EU regulation.


2021 ◽  
Author(s):  
Elia Ciani ◽  
Kristine von Krogh ◽  
Rasoul Nourizadeh-Lillabadi ◽  
Ian Mayer ◽  
Romain Fontaine ◽  
...  

AbstractMale Atlantic salmon (Salmo salar) display different sexual strategies, maturing either as parr during the freshwater phase (as sneaky spawners), or as post smolts following one or several years at sea. First sexual maturation (puberty) occurs at different times depending on environmental and genetic factors. To improve our knowledge on the timing (age and season) of first sexual maturation in Atlantic salmon male parr, we investigated pubertal activation in second generation farmed salmon from the Norwegian river Figgjo, reared under natural conditions of photoperiod and water temperature. Histological analysis, in combination with morphometric measurements, plasma androgen levels and pituitary gonadotropin gene expression analysis revealed that, as previously reported, some male parr initiated early sexual maturation in spring at one year of age. Interestingly, some male parr were observed to initiate sexual maturation already in autumn, six months after hatching (under-yearlings), much earlier than reported in previous studies. One-year old maturing males showed a low induction in gonadotropin levels, while under-yearling maturing males displayed a significant increase in fshb transcripts as compared to immature fish. Plasma testosterone, detectable also in immature males, increased constantly during testes development, while 11-ketotestosterone, undetectable in immature and early maturing males, increased during more advanced stages of maturation. A mild feminization of the testes (ovotestes) was detected in a subset of samples. This study brings new knowledge on the little investigated field of sexually maturing under-yearlings in Atlantic salmon. This is also the first study comparing the physiology of under-yearling vs one-year old maturing male parr, thus bringing new insights to the remarkable plasticity of Atlantic salmon puberty.


Author(s):  
Bogdan Manațe ◽  
Florin Fortiş ◽  
Philip Moore

The rapid expansion of the Internet of Things (IoT) will generate a diverse range of data types that needs to be handled, processed and stored. This paper aims to create a multi-agent system that suits the needs introduced by the IoT expansion, thus being able to oversee the Big Data collection and processing and also to maintain the semantic links between the data sources and data consumers. In order to build a complex agent oriented architecture, we have assessed the existing agent oriented methodologies searching for the best solution that is not bound to a specific programming language of framework, and it is flexible enough to be applied in such a divers domain like IoT. As complex scenario, the proposed approach has been applied to medical diagnosis and motoring of mental disorders.


2020 ◽  
Vol 37 (10) ◽  
pp. e4.1-e4
Author(s):  
Graham McClelland ◽  
Karl Charlton ◽  
Jacqueline Mains ◽  
Karen Millican ◽  
Caroline Cullerton

BackgroundAmbulance services transport patients with infections and diseases and could pose a cross transmission risk to patients and staff through environmental contamination. The literature suggests that environmental pathogens are present on ambulances, cleaning is inconsistent and patient/staff impact is difficult to quantify. Eco-Mist developed a dry misting decontamination system for ambulance use called AmbuGard which works in <30 minutes and is 99.9999% effective against common pathogens. The research question is ‘What pathogens are present on North East Ambulance Service ambulances and what impact does adding the AmbuGard to the deep cleaning process make?’MethodsA two armed, randomised controlled trial enrolled fourteen ambulances during their regular 24 week deep clean which were 1:1 randomised to deep cleaning (control arm) or deep cleaning plus AmbuGard (intervention arm). Polywipe swabs were taken before and after cleaning from five locations selected for high rates of contact (steering wheel, shelf, side door grab rail, patient seat armrest, rear door handle/grab rail). Microbiology culture methods identified the presence and amount of bacterial organisms present including the selected pathogens: Enterococcus spp.; Enterobacter spp.; Klebsiella spp.; Staphylococcus aureus; Acinetobacter spp.; Pseudomonas spp.; Clostridium difficile; coagulase-negative staphylococci (CoNS)). The researcher taking the swabs and the laboratory were blinded to the trial arm.ResultsPathogens of interest were found on 10 (71%) vehicles. CoNS were found on all vehicles. Pathogens were found on all locations swabbed. Normal deep cleaning was effective at eliminating pathogens and the addition of AmbuGard showed no obvious improvement in effectiveness.ConclusionPathogens associated with healthcare acquired infections were found throughout all ambulances. Normal deep cleaning was effective and adding AmbuGard showed no obvious improvement. This was a small study at a single point in time. Further research is needed into temporal trends, how to reduce pathogens during normal clinical duties and patient/staff impact.


2019 ◽  
Vol 76 (5) ◽  
pp. 695-704 ◽  
Author(s):  
Brendan F. Wringe ◽  
Eric C. Anderson ◽  
Nicholas W. Jeffery ◽  
Ryan R.E. Stanley ◽  
Ian R. Bradbury

Hybridization between wild and escaped cultured Atlantic salmon (Salmo salar) can threaten the stability and persistence of locally adapted wild populations. Here we describe the development and validation of a genomic-based approach to quantify recent hybridization between escapee and wild salmon in the western Atlantic. Based on genome-wide single nucleotide polymorphism (SNP) scans of wild and cultured salmon, collectively diagnostic panels were created for Newfoundland and the Canadian Maritimes. These panels were capable of both discriminating hybrids from nonhybrids and of correctly assigning individuals to hybrid class (i.e., pure wild, pure farm, F1, F2, and backcrosses) with a high degree of accuracy (Newfoundland 96 SNPs > 90%, Maritimes 720 SNPs > 80%). These genomic panels permit the assessment of the impacts of past and future farmed salmon escape events on wild populations and can inform the protection and conservation of wild Atlantic salmon genetic integrity in the western Atlantic.


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