Tromsø, Norway
Tromsø, Norway

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Karlsson S.,Nofima Marine | Moen T.,Aqua Gen AS | Moen T.,Norwegian University of Life Sciences | Lien S.,Norwegian University of Life Sciences | And 2 more authors.
Molecular Ecology Resources | Year: 2011

Genetic interactions between farmed and wild conspecifics are of special concern in fisheries where large numbers of domesticated individuals are released into the wild. In the Atlantic salmon (Salmo salar), selective breeding since the 1970's has resulted in rapid genetic changes in commercially important traits, such as a doubling of the growth rate. Each year, farmed salmon escape from net pens, enter rivers, and interbreed with wild salmon. Field experiments demonstrate that genetic introgression may weaken the viability of recipient populations. However, due to the lack of diagnostic genetic markers, little is known about actual rates of gene flow from farmed to wild populations. Here we present a panel of 60 single nucleotide polymorphisms (SNPs) that collectively are diagnostic in identifying individual salmon as being farmed or wild, regardless of their populations of origin. These were sourced from a pool of 7000 SNPs comparing historical wild and farmed salmon populations, and were distributed on all but two of the 29 chromosomes. We suggest that the generic differences between farmed and wild salmon at these SNPs have arisen due to domestication. The identified panel of SNPs will permit quantification of gene flow from farmed to wild salmon populations, elucidating one of the most controversial potential impacts of aquaculture. With increasing global interest in aquaculture and increasing pressure on wild populations, results from our study have implications for a wide range of species. © 2011 Blackwell Publishing Ltd.


Altintzoglou T.,Nofima Marine | Vanhonacker F.,Ghent University | Verbeke W.,Ghent University | Luten J.,Nofima Market
Aquaculture International | Year: 2011

Consumers in many European countries do not equally meet the recommended daily intake levels for fish consumption. Various factors that can influence fish consumption behaviour have been identified but limited research has been performed on fish consumption behaviour, discriminating between farmed and wild fish. The present survey study confirmed differences in total fish consumption, farmed fish and wild fish consumption behaviour in Belgium, Norway and Spain. Spanish consumers consumed more frequently fish of each category than Norwegian consumers. Belgian consumers reported the lowest consumption frequency of fish. Accordingly, health involvement and attitudes towards fish consumption decreased from Spain over Norway to Belgium, suggesting a positive association of health involvement and attitudes towards fish consumption with total fish consumption. Similar effects were found for farmed and wild fish consumption. In general, consumers in all countries were poorly aware of the origin of the fish they consume, despite the mandatory indication of origin on fish labels. Across countries, an increased awareness about fish origin was found with increased fish consumption. The findings of the study indicate that farmed and wild fish consumption should be further stimulated among Belgian, Norwegian and Spanish consumers in association with a healthy and positive meal. Additionally, given the limited awareness of the origin of fish, transparency on the issue of farmed origin will be important in order to anticipate potential adverse communication. © 2010 The Author(s).


Vanhonacker F.,Ghent University | Altintzoglou T.,Nofima Marine | Luten J.,Nofima Marine | Verbeke W.,Ghent University
British Food Journal | Year: 2011

Purpose: This study aims to gain insights into the relevance and market potential of fish origin (farmed or wild) among consumers in Belgium, Norway and Spain. Design/methodology/approach: Cross-sectional data were collected through a consumer survey (n=1,319), conducted in November-December 2007 in three European countries: Belgium, Norway and Spain. The study describes personal and food characteristics, as well as consumer attitudes and knowledge related to fish origin. Further, these characteristics were analysed in terms of their impact on the choice of either farmed or wild fish, using bivariate analyses. Findings: In general, European consumers have little knowledge or awareness regarding the origin of fish. This results in uncertainty in consumers' perception of farmed fish in particular. The study is in line with previous ones suggesting that perceptions of aquaculture and farmed fish are based more on emotions than on rational considerations. Still, the perception of farmed fish is positive in general. Consumers do not prioritise fish origin as an information cue, although variation is present between different consumer groups. Consumers of predominantly farmed versus wild fish did not have a very distinct profile, which corroborates with the only modest significance of fish origin as a product-specific information cue during the fish purchase and consumption decision process. Originality/value: The strength of the paper pertains to its international scope, and to the diversity of countries selected in terms of relevant variables. Also, the growing relevance of aquaculture as a fish production method and farmed fish as a food product makes results and findings of the study topical and of practical relevance. © Emerald Group Publishing Limited.


Altintzoglou T.,Nofima Marine | Verbeke W.,Ghent University | Vanhonacker F.,Ghent University | Luten J.,Nofima Market
Journal of Aquatic Food Product Technology | Year: 2010

This study investigated the effect of balanced, nonpersuasive information related to safety, healthiness, and sustainability of aquaculture on the image of farmed fish among European consumers. It was demonstrated that there is neither positive nor negative influence of this type of information on the predominantly positive image of fish from aquaculture. Consumers who were exposed to information related to the EU origin and aquaculture related guarantee reported a more positive image of farmed fish. These results provide valuable input for transparent communication about fish farming practices which might increase consumer trust and will not harm the image of fish from aquaculture. Increasing consumers' knowledge about aquaculture and its positive effects on the image of farmed fish is also discussed as a pathway for maintaining and improving aquaculture's positive image in the future. Copyright © Taylor & Francis Group, LLC.


Hansen O.J.,Nofima marine | Puvanendran V.,Nofima marine | Jostensen J.P.,Tromso Fiskeindustri AS TROFI | Ous C.,Tromso Fiskeindustri AS TROFI
Aquaculture Research | Year: 2011

Effects of two weaning diets that differed in phospholipid (PL) classes on growth, survival and deformities of cod larvae and early juveniles were evaluated. Cod larvae were fed rotifers until 21 days post hatch (dph) and then weaning onto dry diet started. One group of larvae were fed a control diet with low levels of phosphatidylcholine (PC), PE and phosphatidylinositol (PI) and the other group of larvae were fed with an experimental diet containing higher levels of PC, PE and PI. Larvae fed with the control diet were significantly smaller than larvae fed with the experimental diet at the end of the experiment. Swim bladder abnormalities were significantly higher in larvae fed with control diet at 35dph than the larvae fed with experimental diet; however, no significant difference was evident at 42dph. Vertebral deformities were significantly higher in larvae fed with control diet and scoliosis was significantly different between the treatments. Survival was also significantly higher in the experimental group. Our results indicate that dietary levels of PL, PC and PI may affect the cod larval growth, survival and deformities. More detail studies are needed to find out the optimal levels of these important PL classes in larval cod diets. © 2010 Blackwell Publishing Ltd.


Skagemo V.,Nofima Marine | Skagemo V.,Norwegian University of Life Sciences | Sonesson A.K.,Nofima Marine | Meuwissen T.H.E.,Norwegian University of Life Sciences | Rye M.,Akvaforsk
Aquaculture | Year: 2010

We studied a typical breeding nucleus with dissemination of genetic material directly from the nucleus to the grow-out level by stochastic simulation. Profits could be increased through production and dissemination of specialised stocks suited for specific production environments or markets. Truncation selection of 50 sires and 200 dams (trunc ♂2.5% ♀10%) and of 5 sires and 25 dams (trunc ♂0.25% ♀1.25%) were compared to random selection of 50 sires and 200 dams (rand ♂2.5% ♀10%). Higher profit was obtained for all truncation selection schemes as compared to random selection, and increasing with decreasing proportion selected. By optimising the selection of parents, which are used for dissemination from the nucleus to the grow-out, instead of using randomly selected nucleus parents, an additional response corresponding of approximately 1.5 generations of selection in the nucleus was achieved. The effect of the correlation between the nucleus breeding goal and the breeding objective of the grow-out was that profit was highest when the correlation was high. With a negative genetic correlation between the traits, profit was still high if the trait with the highest heritability (i.e. the trait measured on candidate itself) had the highest economic value. The range of ΔF in the 7th generation in the nucleus was [- 0.0075-0.0269] with SD equal to 0.0056. The average over all the replicates was 0.0095. This study showed that selection of specialised stocks for specific breeding objectives from the nucleus to the grow-out level will give the grow-out producers a direct and extra genetic improvement and that selecting breeders in the nucleus for dissemination gives also more flexibility for a final product, by adapting economic weights for each grow-out producer. © 2010 Elsevier B.V. All rights reserved.


Canon Jones H.A.,University of Cambridge | Hansen L.A.,Nofima Marine | Noble C.,Nofima Marine | Damsgard B.,Nofima Marine | And 2 more authors.
Applied Animal Behaviour Science | Year: 2010

The role of behavioural interactions in the development of fin damage amongst Atlantic salmon (Salmo salar) undergoing feed-restriction was investigated using social network analysis. Dorsal fin damage, particularly erosion, was seen only in groups subjected to feed-restriction. The amount of dorsal fin damage was positively correlated with aggression and fin-biting. Feed-restricted fish exhibited significantly lower weight gain, reduced growth-rate and body condition but no differences in total length. Social networks based on aggressive interactions in feed-restriction groups showed significantly lower distance, and higher density, higher clustering coefficient and higher in and out degree centrality. These findings indicated higher and more intense aggressive interactions in feed-restricted fish. A distinctive separation of roles according to aggression was found in feed-restriction groups where initiators had high out-degree centrality and receivers had high in-degree centrality. Fish initiating aggressive interactions had less fin damage, gained more weight and attained more central positions within the school. Fish receiving aggression had more fin damage and gained less weight. Association networks in the feed-restricted groups had significantly lower values for transitivity and distance with a tendency for higher centrality. These findings indicate higher levels of interaction and an imbalance in their relationships. We demonstrated the value of social network analysis in investigating behavioural interactions associated with aggression and the development of fin damage in Atlantic salmon. © 2010 Elsevier B.V.


Schram E.,Wageningen University | Schelvis-Smit R.A.A.M.,Wageningen University | van der Heul J.W.,Wageningen University | Luten J.B.,Nofima Marine
Aquaculture Research | Year: 2010

We wanted to optimize the procedure for the selenium enrichment of farmed African catfish, using garlic as dietary selenium source. In the first experiment we established the relation between the length of the selenium enrichment period and the resulting total selenium level in the fillet of the fish. It was found that at a dietary level of 11.7 mg kg-1 Se, a total selenium level in the fillet of 0.7 mg kg-1 was reached in a relatively short enrichment period of 10 days before harvest. In the second experiment we studied the effect of depuration on the selenium level in the fillet and the sensory properties of selenium-enriched African catfish. It was found that total selenium levels in the fillet were not affected during a 7-day depuration period, while garlic odours and flavours in the raw and cooked fillets were significantly reduced after 2 days of depuration. We concluded that selenium enrichment of farmed African catfish can be obtained by selenium-enriched finishing diets, while garlic odours and flavours resulting from dietary garlic can be effectively reduced in the fillet during a short depuration period without negatively affecting fillet levels of total selenium. © 2009 The Authors. Journal Compilation © 2009 Blackwell Publishing Ltd.


Karlsson S.,NOFIMA Marine | Moen T.,Aqua Gen AS
BMC Research Notes | Year: 2010

Background. An increasing number of aquaculture species are subjected to artificial selection in systematic breeding programs. Rapid improvements of important commercial traits are reported, but little is known about the effects of the strong directional selection applied, on gene level variation. Large numbers of genetic markers are becoming available, making it feasible to detect and estimate these effects. Here a simulation tool was developed in order to explore the power by which single genetic loci subjected to uni-directional selection in parallel breeding populations may be detected. Findings. Two simulation models were pursued: 1) screening for loci displaying higher genetic differentiation than expected (high-FSToutliers), from neutral evolution between a pool of domesticated populations and a pool of wild populations; 2) screening for loci displaying lower genetic differentiation (low-FSToutliers) between domesticated strains than expected from neutral evolution. The premise for both approaches was that the isolated domesticated strains are subjected to the same breeding goals. The power to detect outlier loci was calculated under the following parameter values: number of populations, effective population size per population, number of generations since onset of selection, initial FST, and the selection coefficient acting on the locus. Among the parameters investigated, selection coefficient, the number of generation since onset of selection, and number of populations, had the largest impact on power. The power to detect loci subjected to directional in breeding programmes was high when applying the between farmed and wild population approach, and low for the between farmed populations approach. Conclusions. A simulation tool was developed for estimating the power to detect artificial selection acting directly on single loci. The simulation tool should be applicable to most species subject to domestication, as long as a reasonable high accuracy in input parameters such as effective population size, number of generations since the initiation of selection, and initial differentiation (FST) can be obtained. Identification of genetic loci under artificial selection would be highly valuable, since such loci could be used to monitor maintenance of genetic variation in the breeding populations and monitoring possible genetic changes in wild populations from genetic interaction between escapees and their wild counterpart. © 2010 Karlsson et al; licensee BioMed Central Ltd.


Lopez-Olmeda J.F.,University of Murcia | Noble C.,Nofima Marine | Sanchez-Vazquez F.J.,University of Murcia
Fish Physiology and Biochemistry | Year: 2012

Increased aquaculture production has raised concerns about managing protocols to safeguard the welfare of farmed fish, as consumers demand responsible aquaculture practices to provide 'welfare friendly' products. Feeding is one of the largest production cost in a fish farm and can be one of the biggest stressors for fish. Under farming conditions, fish are challenged with artificial diets and feeding regimes, and inadequate feeding conditions cause stress, alteration of normal behavioural patterns, poor performance and eventually diseases and death, which are by no means acceptable neither economically nor ethically. This review aims to highlight the impact of feeding rhythms and feeding time upon physiological and behavioural welfare indicators, which show circadian rhythms as well. Therefore, all these variables should be considered when designing feeding strategies in farming conditions and assessing the welfare state of cultured fish. © 2011 Springer Science+Business Media B.V.

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