ISSN:1064-1262    

DOI:10.1080/10641269709388602

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Aquaculture research has been part of the Norwegian aquaculture policy since the appointment of the Lys0 Commission in 1972. In 1993 a major reorganization of the national research system took place. Here the organization of the aquaculture research system, with particular emphasis on the 1980s, is the focus. When the Norwegian government required aquaculture as a priority area for industrial growth in the budget proposal of 1985, a follow‐up of the first governmental initiatives, there was a signal to the research community that the future would bring increased opportunity and funding. The expectations were high in the research community, because aquaculture was a new arena, and it was available to everyone. Because of the rigid structures of the three industrial research councils, the extraordinary governmental funding level was absorbed by the established research system, and the intentions of extraordinary governmental effort impaired. The result is that, as argued here, the governmental effort has maintained intersectoral boundaries in the research system rather than breaking them down in favor of the new discipline known as aquaculture research. The conclusion is that the coordinating and governing institutions must have greater impact in the administration of aquaculture research. Industry‐related research is a political instrument, and as such has to be governed in accordance with democratic institutions.

ISSN:1064-1262    

DOI:10.1080/10641269709388603

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Fish growth is an energetically demanding process. It has been suggested that fish maximum growth rate is limited by the organism's capacity to support energetic demand. We reexamined gill surface area data and found no evidence that maximum growth rate could be limited by the ability to extract oxygen from the environment. We also compared the relationship between aerobic capacity of axial muscle and growth rate for different species and found that muscle aerobic capacity was poorly correlated with growth rate for single individuals or averaged over species. Our estimation of aerobic capacity and cost of protein synthesis in white muscle of cod with growth rates of 1 and 0.12% wet weightday‐1showed that the aerobic capacity of this tissue surpass almost 10 times the energy needed for protein synthesis. Finally, neither the maximum growth rate nor the conversion efficiency during positive growth rate are related to the aerobic capacity of the digestive tract.

ISSN:1064-1262    

DOI:10.1080/10641269709388604

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Being able to influence the gametogenesis of cultured fish so they reproduce clonally, as some do in nature, would provide aquaculturists with powerful options not available to other animal breeders. This article shows why tetraploidizing precursor cell types to oocytes in otherwise diploid fish, coupled with already practiced gynogenetic induction of spawned eggs and sex reversal, could lead to large‐scale cloning of selectively bred or transgenic individuals, and faithful copying of wild fish genomes. How cloning of this sort might be conducted on fish is described and data needs pointed out. Tetraploid copying of diploid clones, further even larger‐scale cloning for aquaculture production, and inter‐ and intra‐clonal crossbreeding are also topics of consideration.

ISSN:1064-1262    

DOI:10.1080/10641269709388605

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The application of large marine enclosures for early life history studies has revealed important information for cultivation methods of fish larvae. During the 1970s and 1980s extensive and semiintensive methods were developed for cultivation of Atlantic cod, turbot, Atlantic halibut, seabass, and sea bream. In Norway, the lagoon enclosure technique was the predominant method in the late 1980s. The extensive method, applied mostly for cod, is defined as larval rearing in lagoons or ponds, where larval feeding is based entirely on natural plankton production in the system. In contrast, the semiintensive method is defined as larval rearing in large tanks or plastic bags, where food organisms are collected and concentrated from extensive lagoon or pond systems before being fed to the fish larvae. Copepods are the predominant food item produced with these techniques, but variability of copepod productivity in relation to the food demands of the larval population has been a major problem. At present in Norway only halibut juveniles are commercially reared using such systems. In Denmark, extensive rearing techniques for turbot in concrete tanks were developed in the early 1980s and are still commercially applied in a more semiintensive manner. This article reviews the development of the extensive and semiintensive rearing methods for marine fish larvae and gives a short outline of the different adaptations of the methods. Commercialization of the methods is discussed in relation to their constraints.

ISSN:1064-1262    

DOI:10.1080/10641269709388606

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor