Aquaculture production by species (fish_aq)

National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRS)

Compiling agency: Ministerio de Agricultura, Pesca y Alimentación. Ministry of Agriculture, Fisheries and Food.


Eurostat metadata
Reference metadata
1. Contact
2. Statistical presentation
3. Statistical processing
4. Quality management
5. Relevance
6. Accuracy and reliability
7. Timeliness and punctuality
8. Coherence and comparability
9. Accessibility and clarity
10. Cost and Burden
11. Confidentiality
12. Comment
Related Metadata
Annexes (including footnotes)
 



For any question on data and metadata, please contact: Eurostat user support

Download


1. Contact Top
1.1. Contact organisation

Ministerio de Agricultura, Pesca y Alimentación. Ministry of Agriculture, Fisheries and Food.
1.2. Contact organisation unit

Subdirección General de Análisis, Coordinación y Estadística. Deputy Directorate General for Analysis, Coordination and Statistics.
1.5. Contact mail address

Ministerio de Agricultura, Pesca y Alimentación. Paseo de la Infanta Isabel, 1. MADRID 28014. Spain


2. Statistical presentation Top
2.1. Data description

Main characteristics

2.1.1 Describe shortly the main characteristics of the statistics 

Aquaculture production statistics as defined in Regulation (EC) 762/2008 contain four different datasets:
AQ2A - Aquaculture production volume at first sale for human consumption (excluding hatcheries and nurseries) by species, FAO Major Area, cultivation method and aquatic environment.
AQ2B - Production of fish eggs (roe) for human consumption at first sale by species, by FAO Major Area, cultivation method and aquatic environment.
AQ3 - Input to capture-based aquaculture, i.e. wild seed, by species.
AQ4 - Production of juveniles and fertilised eggs at first sale for further on-growing or release to the wild by species.
The production volume is measured in tonnes live weight (TLW) and economic value as unit price in national currency per tonne (NAC_T/TLW), with the exception of juveniles and fertilised eggs which are measured in numbers. Additionally, for the case of algae and cianobacteria, production is provided in DRY WHEIGHT for all the time series.
In addition, a fifth dataset (AQ5) provides information on the size (in hectares, 1000 cubic metres or metres) of aquaculture production facilities segmented by species group, FAO Major Area, cultivation method and aquatic environment.

 


Reference period

2.1.2 Reference period of the data collection 

2022


National legislation

2.1.3 Is there a national legislation covering these statistics? Yes
If Yes, please answer all the following questions.
2.1.4 Name of the national legislation

National Statistics Plan (NSP) 2021-2024, adopted by Royal Decree 1110/2020, of 15th of December of 2020. The NSP includes 2 statistical actions on aquaculture: Aquaculture holdings survey (number 8054) and Aquaculture economic survey (number 8055)
2.1.5 Link to the national legislation

https://www.boe.es/eli/es/rd/2020/12/15/1110/dof/spa/pdf

 
2.1.6 Responsible organisation for the national legislation

Ministry of Economic Affairs and Digital Transformation. Instituto Nacional de Estadística/National Statistics Institute

Ministry of Agriculture, Fisheries and Food. Ministerio de Agricultura, Pesca y Alimentación
2.1.7 Year of entry into force of the national legislation

1989
2.1.8 Please indicate which variables required under EU regulation are not covered by national legislation, if any.
2.1.9 Please indicate which national definitions differ from those in the EU regulation, if any.
2.1.10 Is there a legal obligation for respondents to reply? Yes


Additional comments to data description
2.2. Classification system

The following variables are recorded with regard to aquaculture production:
a) 'Species' means the species of aquatic organisms identified using the international 3-alpha code as defined by the FAO (ASFIS List of Species for Fishery Statistics Purposes). Individual species are grouped in aggregates according to their taxonomy and living habits. These aggregates are specified in the International Standard Statistical Classification of Aquatic Animals and Plants (ISSCAAP) and indicated in the ASFIS list.
b) 'FAO major areas' means the geographical areas as defined by the FAO (CWP Handbook of fishery statistical standards). The FAO major areas covered are: 27 'Northeast Atlantic', 37 'Mediterranean and Black Sea', 34 'Atlantic Eastern Central', 5 'European inland waters', 1 'African inland waters'.
c) 'Cultivation method' includes ponds, cages, tanks and raceways, enclosures and pens, recirculation systems, others and not specified. For molluscs also on-bottom and off-bottom systems.
d) 'Aquatic environment' distinguishes the water types fresh water and salt (sea and brackish) water.
The methods and water types are defined in Annex I of Regulation (EC) No 762/2008.
2.3. Coverage - sector

Commercial aquaculture production for direct human consumption, for human food industry, for animal consumption, for repopulation, for other uses, etc.
2.4. Statistical concepts and definitions
According to Regulation (EC) 762/2008, aquaculture production means the output from aquaculture at first sale. For fish, crustaceans, molluscs and other aquatic organisms the output from aquaculture for aquariums, of ornamental or functional species, for research purposes and production, which is not intended for sale is not included. The output from aquaculture of aquatic plants at first sale will be recorded notwithstanding their final use.
The production volume is expressed in tonnes live weight [TLW] of the product. This weight includes all shells and bones. Data for the economic value of the production are reported as unit price in national currency per tonne [NAC_T]. The production of hatcheries and nurseries is reported in numbers and expressed in millions. Data on the structure of the aquaculture sector are expressed in thousand cubic metres, hectares or, optionally, 'metres rope length' according to the method.

Marine aquaculture: aquaculture using marine water or brackish water in intertidal areas.
Continental aquaculture: aquaculture using continental water (water from rivers, lakes, springs, wells, ...).
Freshwater: water with negligible and constant salinity.
Salty water: water with high level of salinity and which doesn't suffer significant variations in salinty.
Brackish water: water with significant salinity, which is not constantly high, and which can observe sensible variations due to salty or fresh water influence.  
Intertidal area: area between high and low tide.
Aquaculture holding: administratively delimited area or set of facilities located in the same geographical location that, having a holder, natural or legal person responsible for the exploitation, is empowered to carry out aquaculture as determined in the corresponding concession and / or authorization.
Owner of the aquaculture holding: Individual or legal entity, private or public that exercises aquaculture, organizing the assets and rights of the establishment and assuming the risks and civil, social and fiscal responsibility that may arise from the management of said establishment.

Types of facilities and establishments for the cultivation of species
On land: Aquaculture in buildings and / or artifacts located on land (tanks and pipelines, ponds and recirculation systems).
In natural enclaves: aquaculture carried out in natural enclaves of the continental zone and maritime-terrestrial environments (estuaries, marshes and lagoons, ponds and small reservoirs, lakes and lagoons, ....).
Horizontal aquaculture: Horizontal aquaculture in maritime-terrestrial land or in marine land, in deep or raised areas (aquaculture parks, aquaculture in natural banks, aquaculture in tables or other raised assets, ...).
Vertical aquaculture:  Vertical lines in sea water, floating or fixed to the sea floor (floating rafts,  fixed rafts, long‐lines, empalizadas, etc.).
Cage culture: Aquaculture in cages and other volume artifacts located in the water (floating cages, submerged cages, enclosures, netting fences, ...,).
Production: Quantity of each grown species that leaves the holding after finishing one or several phases of its life cycle.
Types of aquaculture according to phases of the life cycle of the species:
Laying: External action (induced laying) or natural process (natural laying) by which the species targeted by aquaculture release their eggs, larvae or spores into the water.
Incubation or breeding: Incubation and / or hatching-rearing of eggs and larvae or spores released into the water in the laying phase.
Pre-grow: Acclimation of the fry, postlarvae and seeds resulting from the incubation and breeding.
Fattening to commercial size: Increase in the weight of cultivated individuals to the considered commercial size for consumption.
Fattening to sexual maturity: fattening up to the sexual maturity of the individuals
2.5. Statistical unit

Aquaculture production facility (establishment).
2.6. Statistical population

All commercially active aquaculture production facilities within the national territory (establishments).
2.7. Reference area
2.7.1 Geographical area covered

The entire territory of the country
2.7.2 Which special Member State territories are included?

 

Canary Islands, Belears Islands, and the cities of Ceuta and Melilla
2.8. Coverage - Time

2022
2.9. Base period

Not applicable.


3. Statistical processing Top
3.1. Source data

Overall summary

3.1.1 Total number of different data sources used

2
The breakdown is as follows:
3.1.2 Total number of sources of the type "Census"

1
3.1.3 Total number of sources of the type "Sample Survey"

1
3.1.4 Total number of sources of the type "Administrative source"

0
3.1.5 Total number of sources of the type "Experts"

0
3.1.6 Total number of sources of the type "Other sources"

0


Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 3.1 of the annexed Excel file 
3.1.7 Name/Title

Aquaculture holdings survey (with the exception of mussels rafts in Galicia and parks of clams and cockle in Carril, Galicia)
3.1.8 Name of Organisation responsible

Ministerio de Agricultura, Pesca y Alimentación. Ministry of Agriculture, Fisheries and Food.
3.1.9 Main scope

All the population except for the mussels rafts in Galicia, and the parks of clams and cockes in Carril, Galicia, which are done by sampling.
3.1.10 List used to build the frame

Aquaculture holdings' register (Directorio de establecimientos de acuicultura)
3.1.11 Any possible threshold values

None
3.1.12 Population size

889 establishmens
3.1.13 Surveyed entity Production facitlity
3.1.14 If Enterprise, please specify
3.1.15 Additional comments


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 3.1 of the annexed Excel file 
3.1.16 Name/Title

Encuesta de establecimientos de acuicultura (muestreo de bateas de mejillón de Galicia y los parques de cultivo de almeja y berberecho de Carril, en Galicia)

Aquaculture holdings survey (sampling of mussels rafts in Galicia and parks of clams and cockle in Carril, Galicia)
3.1.17 Name of Organisation responsible

Ministerio de Agricultura, Pesca y Alimentación. Ministry of Agriculture, Fishery and Food.
3.1.18 Main scope

Mussels rafts in Galicia and culture parks of clams and cockles in Carril, Galicia
3.1.19 List used to build the frame

Subset of the Aquaculture establishment register (filtering by rafts in Galicia and parks of clams and cockles in Carril, Galicia)
3.1.20 Any possible threshold values

None
3.1.21 Population size

3412 of mussle rafts in Galicia

1287 clams and cockles parks in Carril, Galicia
3.1.22 Surveyed entity Production facitlity
3.1.23 If Enterprise, please specify
3.1.24 Sample size

257 mussle rafts of Galicia out of the total of 3418 mussle rafts of Galicia

169 parks of clams and cockles of Carril out of a total of 1287 of the parks of clams ana cockles of Carril, Galicia.
3.1.25 Sampling basis List
3.1.26 If Other, please specify
3.1.27 Type of sample design Stratified
3.1.28 If Other, please specify
3.1.29 If Stratified, number of strata

5 for the rafts of mussles (based on the locationo of the raft)

5 for the parks of clams and cockles (based on the size of the parks)
3.1.30 If Stratified, stratification criteria Unit location
3.1.31 If Other, please specify
3.1.32 Additional comments

Sample survey


Administrative source

These questions only apply to administrative sources. If there is more than one administrative source, please describe the main source below and the additional ones in table 3.1 of the annexed Excel file 
3.1.33 Name/Title
3.1.34 Name of Organisation responsible
3.1.35 Contact information (email and phone)
3.1.36 Main administrative scope
3.1.37 Geospatial Coverage
3.1.38 Update frequency
3.1.39 Legal basis
3.1.40 Are you able to access directly to the micro data?
3.1.41 Are you able to check the plausibility of the data, namely by contacting directly the units?
3.1.42 How would you assess the proximity of the definitions and concepts (including statistical units) used in the administrative source with those required in the EU regulation?
3.1.43 Please list the main differences between the administrative source and the statistical definitions and concepts
3.1.44 Is a different threshold used in the administrative source and statistical data?
3.1.45 If Yes, please specify
3.1.46 Additional comments


Experts

If there is more than one Expert source, please describe the main one below and the additional ones in table 3.1 of the annexed Excel file 
3.1.47 Name/Title
3.1.48 Primary purpose
3.1.49 Legal basis
3.1.50 Update frequency
3.1.51 Expert data supplier
3.1.52 If Other, please specify
3.1.53 How would you assess the quality of those data?
3.1.54 Additional comments


Other sources

If there is more than one other statistical activity, please describe the main one below and the additional ones in table 3.1 of the annexed Excel file 
3.1.55 Name/Title
3.1.56 Name of Organisation
3.1.57 Primary purpose
3.1.58 Data type
3.1.59 If Other, please specify
3.1.60 How would you assess the quality of those data?
3.1.61 Additional comments

 
3.2. Frequency of data collection

Annual
3.3. Data collection

Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 3.3 of the annexed Excel file 
3.3.1 Name/Title

Aquaculture holdings survey (with the exception of mussels rafts in Galicia and of clams and cockle parks in Carril, Galicia)
3.3.2 Methods of data collection Telephone interview
Face-to-face interview
3.3.3 If Other, please specify
3.3.4 If face-to-face or telephone interview, which method is used? Paper questionnaire
3.3.5 Data entry method, if paper questionnaires? Manual
3.3.6 Please annex the questionnaire used (if very long: please provide the hyperlink)

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/Metodolog%C3%ADa_EncuestaEstablecimientosAcuicultura_tcm30-121880.pdf
3.3.7 Additional comments


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 3.3 of the annexed Excel file 
3.3.8 Name/Title

Aquaculture holdings survey (mussels rafts in Galicia and of clams and cockle parks in Carril, Galicia)
3.3.9 Methods of data collection Telephone interview
Face-to-face interview
3.3.10 If Other, please specify
3.3.11 If face-to-face or telephone interview, which method is used? Paper questionnaire
3.3.12 Data entry method, if paper questionnaires? Manual
3.3.13 Please annex the questionnaire used (if very long: please provide the hyperlink)

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/Metodolog%C3%ADa_EncuestaEstablecimientosAcuicultura_tcm30-121880.pdf
3.3.14 Additional comments


Administrative source

These questions only apply to administrative sources. If there is more than one administrative source, please describe the main source below and the additional ones in table 3.3 of the annexed Excel file 
3.3.15 Name/Title
3.3.16 Extraction date
3.3.17 How easy is it to get access to the data?
3.3.18 Data transfer method
3.3.19 Additional comments


Experts

If there is more than one other statistical activity, please describe the main one below and the additional ones in table 3.3 of the annexed Excel file 
3.3.20 Name/Title
3.3.21 Methods of data collection
3.3.22 Additional comments
3.4. Data validation
3.4.1 Which kind of data validation measures are in place? Manual
Automatic
3.4.2 What do they target? Completeness
Outliers
Aggregates
Consistency
3.4.3 If Other, please specify
3.5. Data compilation
3.5.1 Describe the data compilation process

Data editing (flows and inconsistencies) is included in the data entry procedure

Data are collected and filtered in order to correct possible inconsistencies. Once they are received and after recording them, another check is performed to detect possible devieations as a whole, and if so, these are amended.

In the case of  non response to a question or part of a question, the non response can be classified as partial (part of the question) or total (the entire specific question). For both of these cases, there is a method to impute the answer. So these data will be formed by observed values and imputed values. Imputations are usually done using averages or using the closest possible value, so that variability of the response is not reduced. On the other hand, the lack of occational response generates a higher error rate.

When an establishment has ceased its activity, these cases imply a variation of the initial population and therefore, of the elevation coficient, which thus impies an increase of the level of error.

The lack of total reply to the survey and the change of the strata, are dealt with estimating the values of the strata.

However, it is important to highlight that the Spanish Law of Public Statistics oblies surveyd respondents to participate in the official surveys. 

 

 

 
3.5.2 Additional comments

The collected data correspond to the calendar year; for accounting reasons, aquaculture holdings keep production data by calendar year.
3.6. Adjustment

Optional


4. Quality management Top
4.1. Quality assurance
4.1.1 Is there a quality management system used in the organisation? Yes
4.1.2 If yes, how is it implemented?

The statistics of the Ministry are governed by principles that seek to ensure the quality and credibility of the data. These principles are included in the Code of Good Practice of European Statistics (CBP) and refer, among other aspects, to professional independence, protection of confidentiality, reliability of results, accuracy, timeliness, accessibility , clarity, comparability and coherence.
In this statistical operation, both in the information collection process and in the subsequent data processing processes, there are established quality controls in continuous improvement.
The DGMARE of the European Commission conducted a quality audit of the operation in March 2012, through the private company DEVSTAT.
4.1.3 Has a peer review been carried out? Yes
4.1.4 If Yes, which were the main conclusions?

Favourable.

Carried out in 2022.
4.1.5 What quality improvements are foreseen? Other
4.1.6 If Other, please specify

Improvements in the classification and analysis of the structure of the sector when interacting with existing administrative aquaculture directories at national level
4.1.7 Additional comments
4.2. Quality management - assessment

Development since the last quality report

4.2.1 Overall quality Stable
4.2.2 Relevance Stable
4.2.3 Accuracy and reliability Stable
4.2.4 Timeliness and punctuality Stable
4.2.5 Comparability Stable
4.2.6 Coherence Stable
4.2.7 Additional comments

The statistics of the Ministry are governed by principles that seek to ensure the quality and credibility of the data. These principles are included in the Code of Good Practice of European Statistics (CBP) and refer, among other aspects, to professional independence, protection of confidentiality, reliability of results, accuracy, timeliness, accessibility , clarity, comparability and coherence.
In this statistical operation, both in the information collection process and in the subsequent data processing processes, there are established quality controls in continuous improvement.
A part of the population is thoroughly investigated (census) and another part is investigated by stratified random sampling.
In the exhaustive collection part, each statistical unit represents a unit in the total population.
The units of the collection part by sampling represent their corresponding population, for this it is necessary that the selection of the sampling units be done in a random way.
For sampling, the population of the different groups will be grouped by strata and from them the necessary sample will be drawn randomly, obtaining as many independent sub-samples as strata.
The size of each subsample is previously predetermined by the error level that is set.
The sample size of the Survey of Aquaculture Establishments allows us to offer indicators of the activity of the aquaculture sector within reasonable sampling errors.

Geographic comparability
When researching with this survey the data of production by zones within the Spanish geography, these data can be compared with other studies of aquaculture production elaborated by Spanish NUTS2 regions.
Regarding international comparability, this is possible since the methodology of the survey follows the concepts and definitions of Regulation 762/2008 of the European Parliament and the Council of July 9, 2008 and the community requirements for the collection, management and use of the data of the fishing sector, already referred to above. The use of international classifications allows comparability.

Temporal comparability
There is a homogeneous time series since 2002.
In general, the results are prepared so that, based on the current data, the series can be constructed from the beginning of the collection of the information.
This statistical action is compared with results obtained from the Economic Aquaculture Survey. In particular, the value of the production obtained is compared with the net sales of aquaculture of said Economic Survey and the causes of the differences are investigated, if any, correcting them to ensure consistency between the two surveys. Employment data from this statistical operation are also used to relate them to some economic data from the Economic Aquaculture Survey.
The internal coherence of statistics is a consequence of the application of the same methodological criteria and the same calculation method.

The data is published on the Ministry's website, according to the established publication calendar. It also announces the dissemination of the data when it is carried out, in the section of Statistics News.
Some users can receive information on request.
Microdata are accessible according to an express request and study of anonymization according to the cases, since there are still no general rules in this regard.
There is the possibility of requesting customized information from the person responsible for the statistical operation. When processing these requests, limitations on confidentiality or accuracy are taken into account.
The Methodology can be consulted, for a detailed description of the methods and concepts related to the statistical action, published on the Ministry's website.


5. Relevance Top
5.1. Relevance - User Needs
5.1.1 If certain user needs are not met, please specify which and why

All user needs are met
5.1.2 Please specify any plans to satisfy needs more completely in the future
5.1.3 Additional comments

Among the users of the survey, it is worth mentioning: Public Organizations that can use the information gathered for their management function in the aquaculture sector, European Commission bodies such as DGMARE, Eurostat and JRC (Joint Research Center) that require the data for the study of the aquaculture sector of Spain as a member country of the EU, economic agents of the aquaculture sector such as companies and associations of producers, researchers and the academic and scientific world, media and individuals.
In particular, each of these users has different needs according to the destination and usefulness of the information they need, but in any case, and in a general way, this statistical operation provides knowledge of the activity of the aquaculture sector in Spain.
5.2. Relevance - User Satisfaction
5.2.1 Has a user satisfaction survey been conducted? No
If Yes, please answer all the following questions
5.2.2 Year of the user satisfaction survey
5.2.3 How satisfied were the users?
5.2.4 Additional comments
5.3. Completeness
5.3.1 AQ2A - Data completeness - rate

100%
5.3.2 AQ2B - Data completeness - rate

100%
5.3.3 AQ3 - Data completeness - rate

100%
5.3.4 AQ4 - Data completeness - rate

100%
5.3.5 AQ5 - Data completeness - rate

100%
5.3.6 If not complete, which characteristics are missing?
5.3.7 Additional comments


6. Accuracy and reliability Top
6.1. Accuracy - overall
6.1.1 How good is the accuracy? Good
6.1.2 What are the main factors lowering the accuracy? Non-response error
6.1.3 If Other, please specify
6.1.4 Additional comments
6.2. Sampling error

Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 6.2 of the annexed Excel file 
6.2.1 Name/Title

Encuesta de establecimientos de acuicultura (muestreo bateas de mejillón en Galicia)

Aquaculture holdings survey (mussels rafts in Galicia)
6.2.2 Methods used to assess the sampling error Other
6.2.3 If Other, please specify

 CV
6.2.4 If coefficients of variation are calculated, please describe the calculation methods and formulas

Sampling errors of the sample actually obtained

              where    

 
6.2.5 Sampling error - indicators

Please provide the coefficients of variation in the worksheet CV of the annexed Excel file
6.2.6 Additional comments

Random stratified sampling (by geographical location), choosing production as the main variable
6.3. Non-sampling error

See sections below.
6.3.1. Coverage error

Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 6.3 of the annexed Excel file 
6.3.1.1 Name/Title

Aquaculture holdings survey (with the exception of mussels rafts in Galicia and the parks of clams and cockles in Carril, Galicia)
Over-coverage 
6.3.1.2 Over-coverage - rate

Not available.
Under-coverage 
6.3.1.3 Does the sample frame include all units falling within the scope of this survey? Yes
6.3.1.4 If Not, which units are not included?
6.3.1.5 How large do you estimate the proportion of those units? (%)
6.3.1.6 Impact on the data quality None
Misclassification 
6.3.1.7 Impact on the data quality None
Common units 
6.3.1.8 Common units - proportion

Not available.
6.3.1.9 Additional comments

Inactive aquaculture holdings remain in the Historic Register of holdingss, but are not used for the calculation of the survey frame.


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 6.3 of the annexed Excel file  
6.3.1.10 Name/Title

Aquaculture holdings survey (mussels rafts in Galicia and the parks of clams and cockles in Carril, Galicia)
Over-coverage 
6.3.1.11 Over-coverage - rate

Not available.
Under-coverage 
6.3.1.12 Does the sample frame include all units falling within the scope of this survey? Yes
6.3.1.13 If Not, which units are not included?
6.3.1.14 How large do you estimate the proportion of those units? (%)
6.3.1.15 Impact on the data quality None
Misclassification 
6.3.1.16 Impact on the data quality None
Common units 
6.3.1.17 Common units - proportion

Not available.
6.3.1.18 Additional comments


Administrative data

These questions only apply to administrative sources. If there is more than one administrative source, please describe the main source below and the additional ones in table 6.3 of the annexed Excel file 
6.3.1.19 Name/Title
Over-coverage 
6.3.1.20 Over-coverage - rate

Not available.
Under-coverage 
6.3.1.21 Does the administrative source include all units falling within the scope of this survey?
6.3.1.22 If Not, which units are not included?
6.3.1.23 How large do you estimate the proportion of those units? (%)
6.3.1.24 Impact on the data quality
Misclassification 
6.3.1.25 Impact on the data quality
6.3.1.26 Additional comments
6.3.2. Measurement error

Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 6.3 of the annexed Excel file 
6.3.2.1 Name/Title

Aquaculture holdings survey (with the exception of mussels rafts in Galicia and parks of clams and cockles in Carril, Galicia, which are done by sampling)
6.3.2.2 Is the questionnaire based on usual concepts for respondents? Yes
6.3.2.3 Number of censuses already performed with the current questionnaire?

19 (2002-2021)
6.3.2.4 Explanatory notes/handbook for surveyors/respondents?  Yes
6.3.2.5 On-line FAQ or Hot-line support for surveyors/respondents? Yes
6.3.2.6 Other actions taken for reducing the measurement error?

The data collected is cleaned correcting possible inconsistencies; once they are received and after having recorded them, if again possible deviations of global values are observed, inconsistencies are corrected.
6.3.2.7 Additional comments

The types of non-response can be complete or partial. For the part of the study in which the collection is carried out exhaustively there is a method of imputation for cases of non-response, which may affect part of the questionnaire, so that it is partially answered, or a complete questionnaire (refusal of the respondent, inability to contact the informant, etc.).


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 6.3 of the annexed Excel file 
6.3.2.8 Name/Title

 

Aquaculture holdings survey (mussels rafts in Galicia and parks of clams and cockles in Carril, Galicia)
6.3.2.9 Is the questionnaire based on usual concepts for respondents? Yes
6.3.2.10 Number of surveys already performed with the current questionnaire?

19 (2002-2021) for the rafts in Galicia of mussels

1 (2021) for the parks of clams and cockles in carril, Galicia. However the questionnaire was the same in the previous year. the change only applies to the sampling methodology.
6.3.2.11 Explanatory notes/handbook for surveyors/respondents?  Yes
6.3.2.12 On-line FAQ or Hot-line support for surveyors/respondents? Yes
6.3.2.13 Other actions taken for reducing the measurement error?

The data collected is cleaned correcting possible inconsistencies; once they are received and after having recorded them, if again possible deviations of global values are observed, inconsistencies are corrected.
6.3.2.14 Additional comments
6.3.3. Non response error

Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 6.3 of the annexed Excel file 
6.3.3.1 Name/Title

Encuesta de establecimientos de acuicultura (excepto bateas de mejillón de Galicia)

Aquaculture holdings survey (with the exception of mussels rafts in Galicia)
6.3.3.2 Unit non-response - rate

7,12%
6.3.3.3 How do you evaluate the recorded unit non-response rate in the overall context? Low
6.3.3.4 Measures taken for minimising the unit non-response Imputation
6.3.3.5 If Other, please specify
6.3.3.6 Item non-response rate

7,85%
6.3.3.7 Item non-response rate - Minimum

0,78%
6.3.3.8 Item non-response rate - Maximum

4,31%
6.3.3.9 Which items had a high item non-response rate? 

Inputs
6.3.3.10 Additional comments

In Table 6.3.3, in the section: "Have you carried out an analysis of the lack of response at the unit level?" Non-response is solved by imputations. In this case, the previous phases when the holding has been declaring have been taken into account, so that if in previous years it did not declare production in any of the phases, that phase has not been imputed. Hence the differences between phases. In the section "Have you performed an item level non-response analysis?" In this case, what is included are the data of those who have not provided the full data. In the point "In case of imputation, what was the imputation rate (%) ?", we have indicated the sum of both percentages


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 6.3 of the annexed Excel file 
6.3.3.11 Name/Title

Encuesta de establecimientos de acuicultura (muestreo bateas de mejillón de Galicia)

Aquaculture holdings survey (mussels rafts in Galicia)
6.3.3.12 Unit non-response - rate

1,17%
6.3.3.13 How do you evaluate the recorded unit non-response rate in the overall context? Low
6.3.3.14 Measures taken for minimising the unit non-response Imputation
6.3.3.15 If Other, please specify
6.3.3.16 Item non-response rate

1,17%
6.3.3.17 Item non-response rate - Minimum

1,17%
6.3.3.18 Item non-response rate - Maximum

1,17%
6.3.3.19 Which items had a high item non-response rate? 

Those who do not answer do so to the whole questionnaire, nobody answers partially
6.3.3.20 Additional comments

In Table 6.3.3, in the section: "Have you carried out an analysis of the lack of response at the unit level?" Non-response is solved by imputations. In this case, the previous phases when the holding has been declaring have been taken into account, so that if in previous years it did not declare production in any of the phases, that phase has not been imputed. Hence the differences between phases. In the section "Have you performed an item level non-response analysis?" In this case, what is included are the data of those who have not provided the full data. In the point "In case of imputation, what was the imputation rate (%) ?", we have indicated the sum of both percentages
6.3.4. Processing error

Census

These questions only apply to censuses. If there is more than one census, please describe the main census below and the additional ones in table 6.3 of the annexed Excel file 
6.3.4.1 Name/Title

Encuesta de establecimientos de acuicultura (excepto bateas de mejillón de Galicia)

Aquaculture holdings survey (with the exception of mussels rafts in Galicia)
6.3.4.2 Imputation - rate

7,59%
6.3.4.3 Imputation - basis Similar units
Same unit in previous data
6.3.4.4 If Other, please specify
6.3.4.5 Additional comments


Sample survey

These questions only apply to surveys. If there is more than one survey, please describe the main survey below and the additional ones in table 6.3 of the annexed Excel file 
6.3.4.6 Name/Title

Encuesta de establecimientos de acuicultura (muestreo bateas de mejillón de Galicia)

Aquaculture holdings survey (mussels rafts in Galicia)
6.3.4.7 Imputation - rate

1,17%
6.3.4.8 Imputation - basis Similar units
Same unit in previous data
6.3.4.9 If Other, please specify
6.3.4.10 How do you evaluate the impact of imputation on Coefficients of Variation? Not important
6.3.4.11 Additionnal comments
6.3.5. Model assumption error

Not applicable.
6.4. Seasonal adjustment

Not applicable.
6.5. Data revision - policy
6.6. Data revision - practice
6.6.1 Data revision - average size

Not available.
6.6.2 Were data revisions due to conceptual changes (e.g. new definitions)  carried out since the last quality report?
6.6.3 What was the main reason for the revisions?
6.6.4 How do you evaluate the impact of the revisions?
6.6.5 Additional comments


7. Timeliness and punctuality Top
7.1. Timeliness
7.1.1 When were the first  results for the reference period published?

12/2022
7.1.2 When were the final results for the reference period published?

12/2022
7.1.3 Reasons for possible long production times?

The delay in the preparation, collection, debugging and elaboration of results for such a large population is justified. Additionally, data cannot be collectec before June each year because economic data is not available for the companies before then for the previous year.
7.2. Punctuality
7.2.1 Were data released according to a pre-announced schedule (Release Calendar)? Yes
7.2.2 If Yes, were data released on the target date? Yes
7.2.3 If No, reasons for delays?
7.2.4 Number of days between the release date of data and the target date

0


8. Coherence and comparability Top
8.1. Comparability - geographical

To be assessed by Eurostat.
8.1.1. Asymmetry for mirror flow statistics - coefficient

Not applicable.
8.2. Comparability - over time
8.2.1 Length of comparable time series

2002-Today
8.2.2 Have there been major breaks in the time series? No
8.2.3 If Yes, please specify the year of break and the reason
8.2.4 Additional comments
8.3. Coherence - cross domain
8.3.1 With which other national data sources have the data been compared?

Other statistics

The Aquaculture Economic Survey
8.3.2 Describe briefly the results of comparisons

The comparisons with the Aquaculture Economic Survey in relation to the coincident variables are quite good
8.3.3 Additional comments
8.4. Coherence - sub annual and annual statistics

Not applicable.
8.5. Coherence - National Accounts

Not applicable.
8.6. Coherence - internal

Optional


9. Accessibility and clarity Top
9.1. Dissemination format - News release
9.1.1 Do you publish a news release? No
9.1.2 If Yes, please provide a link
9.2. Dissemination format - Publications
9.2.1. Do you produce a paper publication? No
9.2.2 If Yes, is there an English version?
9.2.3 Do you produce an electronic publication? Yes
9.2.4 If Yes, is there an English version? No
9.2.5 Please provide a link

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/acuicultura/encuesta-establecimientos-acuicultura/default.aspx
9.3. Dissemination format - online database
9.3.1 Data tables - consultations

Not available.
9.3.2 Is an on-line database accessible to users? Yes
9.3.3 Please provide a link

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/acuicultura/encuesta-establecimientos-acuicultura/default.aspx
9.4. Dissemination format - microdata access
9.4.1 Are micro-data accessible to users? No
9.4.2 Please provide a link

 
9.5. Dissemination format - other

Optional
9.6. Documentation on methodology
9.6.1 Are national reference metadata files available? No
9.6.2 Please provide a link
9.6.3 Are methodological papers available? Yes
9.6.4 Please provide a link

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/acuicultura/encuesta-establecimientos-acuicultura/default.aspx
9.6.5 Is a handbook available? Yes
9.6.6 Please provide a link

https://www.mapa.gob.es/es/estadistica/temas/estadisticas-pesqueras/acuicultura/encuesta-establecimientos-acuicultura/default.aspx
9.7. Quality management - documentation
9.7.1 Metadata completeness - rate

Not available.
9.7.2 Metadata - consultations

Not available.
9.7.3 Is a quality report available? No
9.7.4 Please provide a link


10. Cost and Burden Top
10.1 Efficiency gains over the last 3 years Further training
10.2 If Other, please specify
10.3 Burden reduction measures since the previous quality report Multiple use of the collected data
10.4 If Other, please specify


11. Confidentiality Top
11.1. Confidentiality - policy
11.1.1 Are confidential data transmitted to Eurostat? Yes
11.1.2 If yes, are they confidential in the sense of Reg. (EC) 223/2009? Yes
11.1.3 Describe the data confidentiality policy in place

The Law 12/1989 on the Public Statistical Function establishes that the Ministry can not disseminate, or make available in any way, individual or aggregated data that could lead to the identification of previously unknown data for a person or entity.
On the other hand, the European Regulation 223/2009 on European statistics establishes the need to establish common principles and guidelines that guarantee the confidentiality of the data used to compile European statistics and access to such confidential data, taking into account technical progress and of the needs of users in a democratic society.
11.2. Confidentiality - data treatment
11.2.1 Describe the procedures for ensuring confidentiality during dissemination

The necessary logical, physical and administrative measures are adopted so that the protection of confidential data is effective, from the data collection to its publication, as well as its storage.
The survey questionnaires include a legal clause that informs about the protection of the data collected.
Once the information collection and processing phases have been completed, paper questionnaires that allow direct identification are kept for the legal time established, guarded in a safe place. Once this period is over, the questionnaires are destroyed.
In the publication of the results tables, the detail of the information is analyzed to avoid that confidential data can be deduced from the statistical units. In case of access to microdata files, they are always anonymous.
11.2.2 Additional comments

Approach for publishing national Aquaculture statistics: Top-down

Procedures for ensuring confidentiality of disseminated data: Omission or Aggregation depending on each case


12. Comment Top

In 2021 sampling of parks of clams and cockles has been introduced for the first time.

Sampling is donde in 5 strata which are establishmed by size. And results are croschecked with data obtained by the two main producers organization.

Data for algae and cianobacteria is provided in dry weight for all the time series.


Related metadata Top


Annexes Top