About the statistics

1. Administrative information

1.1. Name

Aquaculture

1.2. Subject group

10.05 - Fishing and fish farming

1.3. Frequency and timeliness

Preliminary figures: Annually, ca. 6 months after the reference-period (1.1 - 31.12).

Final figures: Annually, ca. 11 months after the reference-period.

1.4. Regional level

County figures and figures for entire country.

County figures are published by the following classification:

Remaining counties include Oppland, Hedmark, Akershus, Oslo, Buskerud, Telemark, Østfold, Vestfold, Aust-Agder og Vest-Agder.

1.5. Responsible division

430 - Division for Primary Industry Statistics

1.6. Legal authority

The Directorate of Fisheries collect data with legal basis in Act no. 79 of 17 June 2005: Act relating to aquaculture.

Statistics Norway recieves data from the Directorate of Fisheries according to the Statistics Act §§2-1, 2-2, 3-2.

1.7. Legal document(EU)

1.8. International reporting

The Directorate of Fisheries reports to Eurostat, FAO and OECD.

2. Background and purpose

2.1. Purpose and history

The purpose of the statistics is to publish relevant information and statistics on the development in Norwegian aquaculture (until 2006 the statistics was named Fish farming).

Statistics on fish farming have been composed since 1971. In the two first years, the task was carried out by Statistics Norway. Since then data collection has been conducted by the Directorate of Fisheries. Statistics Norway has always been responsible for preparing and publishing the final statistics.

The figures are compareable over time, but the statistics comprise more details today than in 1971, when the data collection was carried out for the first time. From 1989, statistics on shellfish and other fish species than salmon and trout were included.

2.2. Users and applications

The main statistic users are public administrations, different organisations, scientists, students, media and the fish farmers themselves. Foreign organisations are also users of the statistics. The statistics are important as a database for analyses of future development. The material is also used in anlyses and economical estimations internally in Statistics Norway.

The data material is used to fulfil Norway's international obligations to report to a number of international organisations as FAO, Eurostat and OECD. The Directorate of Fisheries are responsible for these reports.

3. Statistics production

3.1. Population

The statistics covers the following types of licence to farm fish and/or shellfish:

Final figures contain information from all the licences running. Preliminary figures contain information from the majority of all the licences and calculated values from a small number of licences that still has not been reported. The statistics emphasize salmon and rainbow trout. The common term "rainbow trout", refers to 99 per cent rainbow trout (Salmo gaineri L). The remaining one per cent belong to the species brown trout (Salmo trutta).  

Other species are char/migratory char, cod, halibut, mackerel, eel, saithe (pollock) and turbot. Figures on char, cod and halibut are published solely, while the remaining species are added up and published as other fish species. Farming of these species concerns both commercially farmed fish and feeding of wild caught fish. Relevant species of shellfish are blue mussel, common scallop, oyster, common cockle, horse mussel and lobster. Figures on blue mussel, common scallop and oyster are published solely, while the remaining shellfish species are added up and published as other species.

3.2. Data sources

3.3. Sampling

Complete survey addressing all holders of a licence (per January the year after the reference-year) to farm fish and/or shellfish.

3.4. Collection of data

The Directorate of Fisheries annually sends out a questionnaire to the licencees, meaning those listed in the aquaculture register as of January after the reference year. In accordance to Norwegian legislation, the licencees are under obligation to answer the questionnaires.

To relieve the response burden for companies with several licences, they have as from 2001 only been requiered to fill inn one questionnaire for each type of licence. Companies running licences in several counties still have to fill in seperate questionnaires for each county.

The different questionnaires are:

Each questionnaire has it own guidelines for filling in. The deadline for returning the questionnaires is in March, after the reference year, depending on the type of licence.

Statistics Norway is co-operating with the Directorate of Fisheries and comment on the content of the questionnaires. The Directorate of Fisheries are responsible for sending out, collecting and editing the questionnaires.

3.5. Control and revision

Up to and including 1992, Statistics Norway carried out quality control and correction of data. Since then the Directorate of Fisheries has taken over this work. In addition, they have the professional responsibility of the bulk of the quality controls.

The Directorate of Fisheries controls the data both manually and electronically. For each type of questionnaire there has been prepared a list, which contains absolute and possible errors. These lists are constructed on the basis of professional skills and evaluations. On some occasions, when doubts arise, the respondents are contacted.

The salmon and rainbow trout stocks per 1 January and 31 December and the supplies of salmon and rainbow trout during the year comes from the Register for biomass control. The stock data are controlleld by the companies themselves.

In Statistics Norway the data are controlled once more previous to the production of tables and the preparation of the publication. The Directorate of Fisheries is consulted if any changes take place.

3.6. Estimation

Data is presented as total numbers, percentage and average.

As from 2010, the method used to calcualte loss of fish during production was changed. The loss was until 2010 given in per cent of the the stock of fish per 1 January + supply during the year. This method lead to an unrealistic low loss per cent. As from 2010, the loss is given in per cent of average  stock of fish during the year.

3.7. Confidentiality

Figures based on less than three units (transfers) are not published if this causes risk for identifying any of the units concerned. Furthermore, figures are not published if more than 90 per cent of the registered amount originates from a single unit.

4. Concepts, variables and classifications

4.1. Definitions of the main concepts and variables

Aquaculture

Production of aquatic organisms. Production is any measures taken to enhance living organisms’ weight, size, number, characteristic or quality.

Licence for aquaculture

A permission to farm fish, shellfish or molluscs in accordance to Norwegian legislation (Aquaculture Act). A permission gives the right for a certain type of production of a certain type of species in a certain extent at one or several stated localities.

Operating licence

A licence is considered in operation if there has been production of fish, roe or fry on the licence during the reference year.

Fish for food

Adult fish produced to be consumed. Production of parent fish and fingerling are not included.

Parent fish

Fish that is used to produce roe and milt in artificial fecundation.

FoU-licence, aquaculture

A licence for aquaculture given for the purpose of experiments, research or instructions.

Fingerling production

Production of roe, fry or smolt with a wiev to transferring to other localities.

Smolt

The name of the fish that is ready to enter the sea. At this time it changes in shape and colour and becomes shiny.

Value

Value-added tax is not included in the tables. The value is current value. The value is first-hand value, except of export and import value. The first hand value corresponds to the value of sold slaughtered fish unrefined fresh or frozen. The value of fish further processed in own plants is included.

Quantity

Quantity is quoted as round weight, except of exported and imported quantity, which is quoted as product weight.

Round weight

The weight of the fish before it is gutted. Fish that is delivered gutted is converted into round weight. At the moment, the conversion factor for fish gutted with head is 1.125 and for fish gutted and decapitated 1.2857.

Loss in aquaculture

Loss of fish during production. The loss is given as the number of fish by cause.

Dead fish

Number of fish taken out of the net cages. The dead can be caused by disease, injury and wound without any further specification.

Discarding when slaughtered

The number of fish discarded when slaughtered because of sexual maturity and defects.

Escaping

The number of fish escaped from the fish farms.

Other

The number of fish lost because of predators, theft and other reasons.

Error in counting

The number of fish adjusted in accordance with original supply.

4.2. Standard classifications

Not relevant.

5. Sources of error and uncertainty

5.1. Measurement and processing errors

Statistical data might contain errors. The data from the farmers are of varying quality. In all likelihood the most important error is that some respondents might have given faulty or wrong information.

The routines of revision imply several controls revealing possible and absolute errors. The possible errors are revealed when the variables are outside intervals constructed on the basis of professional assessment. If such intervals are constructed wrongly or/and with bias in any sense, compared to the reality, it will certainly depreciate the quality of the statistics.

5.2 Non-response errors

Licences with no stocks at the end of the year, and/or licences that were not registered with the Directorate of Fisheries' Register for biomass control, are assumed not to be running the following year.

When the preliminary figures are due to be published, there are usually data missing from a small number of companies that still have not reported. This is corrected with an estimation based on previous years production for these companies and information in the Register for biomass control. Six months after the end of the reference period, the coverage in the survey is about 95 per cent for both fish for food-production and hatcheries (salmon, rainbow trout and trout). When corrected with estimated figures for those licences not reported, this survey represents all licences running in the period of reference. The Directorate of Fisheries therefore concludes that the data material qualitatively can be presented as preliminary statistics.

5.3. Sampling errors

Not relevant.

5.4. Other sources of error

Not relevant.

6. Comparability and coherence

6.1. Comparability over time and space

Statistics on sales for food in 1991 were not published because of unreliable data.

6.2. Coherence with other statistics

The statistics are published annually in "Today's statistics" on SSB's websites and in the Statbank

The Directorate of Fisheries publishes preliminary figures in Statistikk for akvakultur. This statistics is based on the same questionnaires as the statistics published by Statistics Norway.

The information from the questionnaires regarding labour input and production are also utilized in The Directorate of Fisheries' survey "Lønnsomhetsundersøkelse for akvakultur, laks og regnbueørret".

7. Availability

7.1. Publications and other links

7.2. Microdata

The Directorate of Fisheries and Statistics Norway stores the data files.


2011 © Statistics Norway