Salmon and rainbow trout are anadromous species, having both a freshwater and saltwater phase to their life cycle. Hatching and smolt production takes place in onshore freshwater tanks, while intensive on growing to market size takes place offshore in marine cages. Hatching of marine species such as cod also takes place in onshore tanks by pumping seawater ashore; ongrowing is then carried out in much the same way as for salmonids. Mussel farming is more extensive with natural spat collection and ongrowing on longlines.
Ninety-five percent of Norwegian production is exported with the EU being the main market. Salmon products however are exported all over the world. Farmed salmon is now one of the main export commodities from Norway and aquaculture and related industries contribute substantially to the country’s economy and it is believed that there is still considerable potential for future growth. The major challenge to the industry is to develop a profitable aquaculture industry based on species other than salmon and to establish a sustainable supply of raw materials for the feed industry.
Today, salmon and rainbow trout farming has developed into a major business along the majority of the Norwegian coast.
Along with the growth in salmonid farming, interest has also become oriented towards other marine species such as the Atlantic cod (Gadus morhua ), the Atlantic halibut (Hippoglossus hippoglossus ) and the spotted wolffish (Anarhichas minor ). All of these species are now in the process of being commercialised.
Oyster culture has also been practiced for more than a hundred years, while interest in other shellfish (mussels, scallops) is more recent.
The service and supply sector is also very important, since feed costs are responsible for more than 50 percent of total production costs. The industry has become a major contributor to employment, as have suppliers of technical equipment, services and logistics. The total employment in the aquaculture sector in Norway is given in table 1.
Table 1. Employment in the aquaculture industry in Norway (man-years) in 2003
Additional employment beyond that detailed in the above table has also been created in related downstream services.
While employment in production has been declining over recent years, this has not been the case with the administration and service sector to the industry where a major change from an unskilled to a skilled labour force has taken place and the number of employees with academic qualifications has increased.
Fig. 1. Distribution and characteristics of the main aquaculture production sites by administrative units (National data, 2003)
The anadromous species Atlantic salmon (Salmo salar ) is native of Norwegian waters, where spawning and smoltification has taken place in the country’s rivers since the last glacial period followed by an ongrowing period at sea. Wild stocks of Atlantic salmon have been caught since ancient times, both in rivers and in the open sea, along with the halibut, salmon has probably been the most valued fish species of all by people living along the coast. Compared to Pacific salmon species, the stocks are small and total landings have never exceeded more than a few thousand tonnes per annum.
The rainbow trout (Oncorhynchus mykiss ) is the only fish species in Norwegian aquaculture which is not native, the species was introduced into Norway around 1900 and was produced in freshwater until the early 1960s. Transfer to sea water following smoltification became a successful process from the start and intensive ongrowing of fish to between 2-6 kg in sea cages has subsequently come to dominate rainbow trout production. There is also a minor, although not insignificant, production of portion size rainbow trout in freshwater in ponds or tanks.
Farming of Atlantic salmon and rainbow trout takes place along the entire coast from Agder in the south to Finnmark in the north. Since 1975 production has been regulated by government licensing.
By the end of 2003, 832 licences for ongrowing in sea water and 242 onshore hatchery/smolt production licences were in operation. Approximately 25 licences for the production of portion size rainbow trout in freshwater ponds are also active, mainly located inland in the south-east of Norway (FHL/Sintef/KPMG, 2004).
Ongrowing in sea water takes place today exclusively in cage systems, the cage systems are based on either square steel platform constructions linked together, or circular plastic rings.
Under normal conditions several licences are operated together, either within the same company or through cooperation between companies. In addition to the licences, farmers must also have permission to utilise specific sites for production. These production sites are required to operate on a single year class basis. In other words, when smolt are put into a site in any particular year, the farmer is not allowed to stock new smolt into the same site before the original fish have been ongrown and all the fish harvested out. The site should then be left empty or fallow, usually for a period of at least six months, before new smolts can be transferred into the site again. With an ongrowing production period varying between 12 to 30 months, one farm should have at least three ongrowing sites available.
Hatcheries are also distributed along most of the coast; maximum smolt production is currently approximately 2.5 million smolts per licence, however again more than one licence can be operated by each producer. For obvious reasons, smolt producers are located close to major freshwater resources.
Today Atlantic salmon is by far the most important species in Norwegian aquaculture, accounting for more than 80 percent of total production while rainbow trout accounts for 10-15 percent.
The cod (Gadus morhua ) has always been the most important species in Norwegian capture fisheries. As a result of seasonal variations in availability and fluctuations in catch from year to year, interest in farming the species has been shown for a long time. However following years of research, production of farmed cod is now growing rapidly.
In the Old Norse language, the halibut (Hippoglossus hippoglossus ) was called ‘the holy fish’. The fish is highly valued due to its taste and relative scarcity from the wild caught fisheries; it is therefore very interesting with respect to its prospects for aquaculture. The species has however, a complex biology and it has been very difficult to establish a stable production of high quality fry. Improvements are being made and today volume is increasing especially due to its high price making production profitable.
Marine fish farms for cod and halibut are distributed along most of the Norwegian coast.
Other fish species
In the southern part of the country, one farm is producing about 600 000 turbot fry (Psetta maxima ) and about 250 tonnes of market size fish per annum. The spotted wolffish (Anarchichas minor) is a very promising aquaculture species which thrives in cold waters and is therefore very well adapted to production in northern regions. This is also true for the charr (Salvelinus alpinus ), of which a small but stable production of between 200 to 300 tonnes a year has been reached.
The blue mussel (Mytilus edulis ) is found along the entire Norwegian coast from the Swedish to the Russian borders. Various experiments in the extensive culture of this species have been carried out over the last 50 years; however, production has yet to reach commercial viability. The main reasons for this are a low price, logistical problems as well as problems with bird predation and marine biotoxins caused by algal blooms. Interest in mussel farming is still high however and production is increasing. Possibilities for high volume production are enormous along the long and highly productive coastline if a commercial breakthrough does occur one day.
Production of the European flat oyster (Ostrea edulis ), both of juveniles and market size oysters, has a long tradition in Norway, and the Pacific cupped oyster (Crassostrea gigas ) has also been imported for aquaculture purposes, but neither of these have reached any significant production volume. Experiments in the cultivation of the great Atlantic scallop (Pecten maximus ) has also been on going for a number of years but again no commercial production has yet been established.
As most of Norwegian aquaculture is based on anadromous fish (salmonids), there needs to be both a freshwater and a seawater stage of the production cycle. The starting point is the production of broodstock fish for the collection of eggs and milt. This is now almost entirely based on participation in genetic breeding programs and there are now 10 specialist producers of fertilised salmon eggs. For farmed salmon, the original breeding population was a selection of wild salmon caught from Norwegian rivers some seven to eight generations ago. Rainbow trout now has around nine to 10 generations of family and individual based selection behind it. Breeding programs are now about to be established both for cod and halibut.
The stripping of salmon takes place between October to mid January, while it begins in mid February for rainbow trout and continues for a couple of months. Fertilized eggs are then incubated, hatched and feeding begun using formulated feed in intensive systems. With the use of artificial light manipulation the first smoltification process takes place in August with smolts then being able to be transferred at sea, the smoltification process will usually be completed by June of the following year. Some freshwater production facilities include both hatcheries and smolt production while others purchase juvenile fry and produce smolt stage salmon.
Fertilised egg production from halibut and cod usually takes place between March and May, but this can be altered by using artificial light (photoperiod manipulation). Unlike salmon and trout, fry of these species have to be fed live natural plankton (rotifers, artemia ) as a starter feed. This commonly takes place in intensive hatcheries, but semi-intensive systems in small inlets are also used for cod fry production.
Ongrowing at sea is now almost exclusively based on intensive cage culture for all finfish species, some halibut is still produced in onshore tanks, but cage culture seems to dominate for this species also. Formulated dry feed account for almost 100 percent of the feed used; however, a small amount of moist pellets is still used. Ongrowing at sea takes from 14 to 30 months, the production at one site usually varies from 800 to 4 000 tonnes in one production cycle, thus making this a very large-scale production system.
The cage systems used have essentially changed little from those first produced, basically; a moored, floating, square, hexagonal or circular unit with a closed net hanging down below it. While the first cages were wooden, with a net volume of 3 400 m3 , today’s cages are either very robust steel square platforms or circular plastic rings with net volumes varying from 3 000 to 40 000 m3 . Each cage usually has a surface area varying from 400 m2 up to 1 100 m2 , the nets can be from 10 to 40 meters deep. Regulations allow a total cage surface area of approximately 2 800 m3 per licence, but total area demand will be much larger when mooring systems are included. Circular plastic cages require more space than steel platforms.
Extensive mussel farming
All mussel farming is based on longlines utilising natural spat collection using hanging collectors, these are sometimes left for final ongrowing, but it has become more common practice to replant or thin the spat as it grows.
Semi-intensive oyster farming
European flat oyster spat is usually produced in specific small, narrow inlets which have a freshwater layer on top, with this layer providing a ‘greenhouse’ effect with a temperature high enough for the oyster to spawn. Spat will then settle on collectors and can be transferred to hanging baskets for ongrowing. Intensive production of scallop and oyster spat has also been researched.
Compared with salmon and rainbow trout, the production volumes and values of other species are still very small.
Total aquaculture production in Norway since 1950 according to FAO Fishery statistics is given in the graph below.
When harvesting, the fish are transported live from the farms to slaughter houses in well-boats, which are capable of carrying loads of between 20 to 200 tonnes of fish. The harvesting stations are designed and have operating practices in place to ensure the best possible levels of animal welfare as well as end product quality. All offal produced during the process is channelled into the fish meal production industry and there is no discharge back to the sea. 70 percent of Norwegian farmed salmon is exported chilled on ice, gutted with head on, and the remainder is processed in a variety of ways (fillets, smoked salmon etc.) or frozen.
Farmed cod and halibut have been very well accepted on both domestic and export markets, as has the blue mussel, these species are all sold fresh, chilled on ice.
Local communities also have important responsibilities in the maintenance of areas for aquaculture purposes.
The Act Relative to Sea Ranching (2000, as amended in 2003) applies to the release and recapture of crustaceans, molluscs and echinoderms for commercial purposes. The Ministry of Fisheries is the institution in charge of the administration of sea ranching, being given the general power to make regulations with regard to all matters stated in the act. The granting of all sea ranching licences is delegated to The Directorate of Fisheries, together with management and enforcement powers.
The Food Production and Food Safety Act (The Food Safety Act 2003) is the main act addressing aspects related to the production, cultivation and distribution of foodstuffs, seeds and feed, as well as issues related to animal and plant health - hence it is applicable to fish production and fish processing as well as fish health. The Ministries of Health, Fisheries and Agriculture are the institutions in charge of the administration of the act, with the power to make regulations regarding all matters of the act. The Norwegian Food Safety Authority is given management and enforcement powers related to the act.
The Act Relative to Prevention of Cruelty to Animals (1974, as amended in 2003) is also of importance for the aquaculture sector.
The EEA agreement imposes several obligations on Norwegian legislation. Of particular interest here is the implementation of EU-legislation on veterinary checks, animal health and hygiene of food.
For more information on aquaculture legislation in Norway please click on the following link:
National Aquaculture Legislation Overview - Norway
Aquaculture research and academic teaching is undertaken by almost all Norwegian universities, the most important being the universities of Tromsø and Bergen, the Agricultural university of Norway, the Norwegian School of Veterinary Science and the Norwegian university of Technology and Science. Teaching is also provided at the regional university colleges.
Vocational training is given by several upper secondary schools based on a two year theoretical education in school plus a two year apprenticeship and leading to a craft certificate.Several public research institutes are also involved in aquaculture research, the most important being the Institute of Fisheries and Aquaculture Research, the Institute of Marine Research, SINTEF Fisheries and Aquaculture and the Institute of Aquaculture Research (AKVAFORSK). The main feed manufacturers (Skretting, EWOS, and Biomar) also have their own research departments and experimental facilities.
Research funding is both public and private based. Public funding is mainly channelled through the Research Council, the universities and research institutes being the main beneficiaries. Private funding has two foundations, firstly, there is a general fee of 0.3 percent on all exports of seafood, generating about US$ 10 millions a year for the Fishery and Aquaculture Research Fund, and secondly, research programs in private companies, either financed wholly by the companies themselves or partly in conjunction with public funding.
Another reason for the success of aquaculture is probably based on logistics. Today’s customers and marketing systems demand quality, stability, and reliability which can be difficult to meet from the wild catch. While this area has seen tremendous development the seafood industry still has a long way to go to catch up with the agriculture sector. Improved logistics systems made possible by aquaculture will also provide an advantage in developing the culture of other species in competition with capture fisheries. Although the relationship between production and demand has been rather unstable at times in the farmed salmon sector, there is no reason to believe that market demand has reached its peak. Further growth is therefore likely, both in relation to salmonids and in particular the ‘new’ species.
What is also seen today is integration between the traditional fisheries and aquaculture. ‘Capture-based aquaculture’ is now creating quite an interest, where fish is caught and brought ashore alive, graded, held in pens, fed if necessary and harvested in response to market demand.
Shortly after the development of intensive salmon farming, severe problems with bacterial diseases (vibriosis, cold water vibriosis, furunculosis etc.) emerged, but the diseases were treated unsuccessfully with antibiotics. The problem continued to increase and by 1987, antibiotic use reached a peak with close to 50 tonnes being administered during the year. A major review of the industry was then undertaken including the implementation of better environmental practices and the development of fish vaccines. This development was extremely successful and antibiotic use in salmon has remained at less than 1 000 kg a year since 1996 (Directorate of Fisheries, 2003 and FHL Havbruk, 2003).
Norwegian fish farming today is a ‘healthy’ business in that diseases and parasite problems are relatively well controlled, pollution problems are reduced, and major improvements have also been made relating to other environmental aspects. However, some viral diseases still cause problems, sea lice control demands meticulous attention and salmon escapes need to be reduced. Further attention to these issues, as well as documentation and traceability throughout the production process will be crucial if customer and consumer demand is to be met.
Limited market access has also been a problem. Following accusations of price fixing, in 1996 the European Union imposed restrictions on Norwegian salmon imports to the EU.
In the long term, limited and possibly dwindling supplies of marine protein and oil for the fish feed industry will probably be the main obstacle for future growth. The amount of marine fish available for use in the fish meal and oil industry is limited and the proportion used for this purpose is diminishing. Plant proteins and oils are already being used to substitute nutrients of marine origin in fish feed and much research effort is being put into optimising the use of alternative raw materials.
FAO . 2005 . Aquaculture production, 2004. Year book of Fishery Statistics - Vol.96/2. Food and Agriculture organization of the United Nations, Rome, Italy.
FHL/Sintef/KPMG . 2004 . Betydningen av Fiskeri- og Havbruksnæringen for Norge – en ringvirkningsanalyse: an analysis of spreading effects from the fisheries and aquaculture sector in Norway.
Direct information from the industry.
FHL Havbruk. 2003 . Aquaculture in Norway. (Information pamphlet).
Gjedrem Trygve (ed). 1993 . Fiskeoppdrett. Vekstnæring for distrikts-Norge. Landbruksforlaget.