Quality description of aquaculture statistics

Compiler: Natural Resources Institute Finland (Luke), starting from 1 January 2015. Previously, the statistics was compiled by the Finnish Game and Fisheries Research Institute (RKTL).

Basis of the statistics: The statistics is compiled based on the Act on the Natural Resources Institute Finland (561/2014) and the act on food and natural resource statistics (562/2014), as well as on Regulation (EC) No 762/2008. The EU data collection programme for the fisheries sector – (EU) 2017/1004, (EU) 2019/909 and (EU) 2019/910 – also requires data collection for aquaculture.

Funding for the statistics: Funding for the statistics is provided from Luke’s assets and from the EU programme for the collection of data in the fisheries sector.

1. Relevance of statistical data

1.1. Data content and purpose of use

The statistics on aquaculture is a summary of the aquaculture production of fish and crayfish in Finland published annually. The statistics presents volumes of the food fish and fry production by species and by area, as well as estimations of the number of fish farms and enterprises and pond farmers operating during the statistical year, the number of production facilities, and the value of food fish and fry production.

The information is used, for instance, in the development of the fisheries sector and the fish processing industry, related decision making, monitoring of measures concerning the industry, and economic monitoring and studies. The statistics is also part of other national and international statistics. In addition to EUROSTAT, aquaculture statistics concerning different countries are compiled and published by, for example, FAO and OECD.

1.2 Concepts and classifications

'Aquaculture production’ comprises fish and crayfish cultivated in Finland for consumption, further farming or stocking purposes, as well as roe produced for food. The statistics only covers products intended for consumption that are not further processed. The statistics does not include deliveries of eggs or newly hatched fry, or crayfish production for human consumption.

Food fish is reported in ungutted weight. Food fish producers can report their production either in gutted or ungutted weight. In the production estimate, the gutted rainbow trout and European whitefish are converted into ungutted fish by using the coefficients of 1.20 and 1.10, respectively. The food fish production also includes the fish supplied for fishing ponds.

The value of food fish, roe and fry production is calculated using the average producer prices. The value of rainbow trout and European whitefish production is calculated on the basis of the prices collected by the Finnish Fish Farmers’ Association. The average prices of other food fish species, roe and fry are calculated on the basis of production values submitted by farmers. The values are given excluding VAT.

The regional division used for aquaculture statistics follows the regional division of the fisheries units of the Centres for Economic Development, Transport and the Environment (ELY Centres).

1.3 Scope of research and reporting periods

The data in the aquaculture statistics are based on the notifications submitted to Luke by fish farmers. The questionnaire is targeted at all fish and crayfish farming enterprises. The same enterprise may have several fish farms, and the production data must be submitted for each farm separately. ‘Fish farm’ typically refers to all production units that usually have a separate fish farming permit granted by the Water Court.

1.4 Users’ points of view

Feedback from users is monitored and taken into account when developing the statistics. Structural changes in the industry are also considered in the development of the statistics. Furthermore, it is ensured that the content of the statistics and the usability of data fulfil the needs of international statistics (EUROSTAT, FAO).

2. Accuracy and reliability of data

2.1 Research method

The aquaculture statistics is an overall study whose population consists of the fish farms in the Aquaculture Register at the end of the statistical year. Luke collects production information from the fish farmers by a postal questionnaire with an electronic reply option. The survey is conducted at the beginning of the year following the statistical year. Questionnaires are mailed to all fish farming enterprises, which may have one or several production units. The information is solicited separately from each production unit. Exceptions are pond farmers, which is enquired enterprise-specifically. Contact is made at least two times during the data collection. Additionally, those who do not respond to the postal questionnaire are contacted over the telephone, where required. The production information concerning Åland is received from the Provincial Government of Åland.

To compensate for non-response, the food fish enterprises are post-stratified on the basis of the location of the enterprise and information of the Aquaculture Register about farm activity. In fry production, the strata basis also consisted of the location of the enterprise and the information of the Aquaculture Register regarding farm activity. The non-response error was corrected by using strata-specific coefficients. The information provided by the Provincial Government of Åland are handled as census data. Deficient data on the value of fry production by species are substituted by estimates made using linear regression models.

In connection with the survey, farmers in the marine areas are also asked about damage caused by seals. In addition, the survey also includes a separate form including questions concerning, for example, employment situation and financial data required by EU-level data collection programmes.

 2.2 Factors affecting the reliability of the statistics

For the reliability of the statistics, it would be important that all enterprises responded to the survey. Unfortunately, there can be great variation in the response rate by year and by production line. In recent year, the response rate for the aquaculture statistics has been in the range of 89-98% due to increasing the number of contacts and telephone surveys.

Uncertainty caused by non-response is biggest for the species whose production is low. These estimates are statistically more inaccurate, because the species are reared only by a few fish farms. For example, the production volumes of scarcely farmed landlocked salmon and arctic char may be somewhat over- or underestimated in the fry statistics. Occurrence of measurement error is monitored by comparing the results with those of previous years. If necessary, the results are checked by contacting the people who answered the questionnaire.

The production volume of species or products is not published if the number of reporting enterprises is fewer than three or if the production volume of a single enterprise is significantly high compared with other enterprises. Since the number of enterprises in the sector is relatively low, it is not often possible to report regional data, This practice aims to ensure the data protection of the reporting companies.

In principle, the statistics covers all cultivated fish and crayfish species. The production of new species is included in the statistics as they are reported by the enterprises. Typically, initially only a few producers are engaged in the production of new species, which generally prevents publishing the production figures for data protection reasons. In such cases, the production figures are included in categories that cover several species.

The address data for the survey are retrieved from the Aquaculture Register maintained by the ELY Centres and controlled by the Finnish Food Authority. All enterprises engaged in aquaculture must be included in the register and notify any changes in their activities to the register (MMM/533/2011). In principle, the Aquaculture Register is a continuously updated register. However, before sending the survey questionnaires, it is first checked that the information contained in the register are up to date.

2.3 Correction of errors

Any errors in the statistics will be corrected as quickly as possible in accordance with the recommendations issued by the advisory council of the Official Statistics of Finland (OSF). Errors will be corrected in statistical databases, and corrected data will be published on the website of the statistics.

3. Timeliness and promptness of data

The aquaculture statistics are issued annually by the end of June of the year following the statistical year. No preliminary information is published about the aquaculture statistics.

The publication date will be announced in the release calendar at www.luke.fi/en/julkistamiskalenteri.

4. Coherence and comparability of statistics

The aquaculture statistics have been compiled nearly in the present form since the year 1988. During 1988-1992, the combined number of stocking and further farming fry were recorded in the statistics. Since 1993, the fry produced for stockings and further breeding have been reported separately. Until 1996, the production figure for salmon also included landlocked salmon. In the statistics published in 1978-1987, only the fry production supplied for stocking purposes was reported by age groups. Consequently, the salmon and trout fry numbers are not directly comparable with later statistics. The Aquaculture Register introduced in 1996 increased the number of the fish farms in 1996.

In some years, the rainbow trout fry production numbers have included deliveries within enterprises, which means that part of the production has been recorded in the statistics twice. Since 1996, attempts have been made to reduce this error in the statistics by making the questions more specific. In 1998-2000, newly hatched juveniles were also included in the crayfish fry production numbers. Therefore, the production numbers of noble crayfish and signal crayfish fry supplied for further farming in 1998-2000 are not directly comparable with other years. Since 2016, signal crayfish has been in the list of invasive species of Union concern and, therefore, the growing of the species has been prohibited ever since.

The aquaculture statistics production figures do not take account of additional growth but reflect the ungutted weight of fish sold or otherwise supplied for consumption or the number of fish fry or crayfish. Consequently, the production figures in the aquaculture statistics are not directly comparable with the additional growth figures for the same year. Where possible, at the end of the year, remaining annual production is often transferred for storing over the winter so that the fish can be sold during the next year. This means that the sales are recorded in the aquaculture statistics for different year than the additional growth gained. Over the long term, however, the figures for sales volumes and additional growth generally start to converge.

5. Accessibility and transparency of data

The statistics is available from Luke’s Statistical Services at www.luke.fi/en/statistics.

Statistics on aquaculture are available since 1980 in a separate database.

Statistics on aquaculture have been published in the Environment series of the Official Statistics of Finland (OSF) from years 1987-1997 and in the Agriculture, Forestry and Fishery Series of the OSF since 1998. The aquaculture time series statistics from 1980-2000 has been presented in the publication Finnish Fishery Time Series (OSF; Agriculture, Forestry and Fishery 2001:60). The name of Fish Culture Statistics was changed into Aquaculture Statistics in 2003.

Luke’s information service responds to any data requests concerning the statistics: tietopalvelu@luke.fi.

A description of the statistics is available on the statistics website.