WOT Centre for Fisheries Research
Sophie Neitzel
The Centre for Fisheries Research (CVO) studies the development of fish and crustacean populations in the sea and the IJsselmeer, in order to advise the government on fisheries management.
All relevant KennisOnline Fishery projects have been brought together in a single overview on Research@WUR.
Data Collection Framework
The (statutory) fisheries research at sea is to a large extent organised and defined at an international level. The EU Common Fisheries Policy is based on information gathered by the Data Collection Framework (DCF).
The Dutch DCF obligations fall within the Statutory Research Tasks (WOT) for fisheries research. In other EU member countries, data collection is organised within similar programmes. The European Commission has formulated guidelines detailing what information the member-states are to collect within the DCF. These guidelines are part of a set of decisions and regulations obligating member states within the EU to collect data on fisheries and fishery resources. The data includes biological information on fisheries resources, as well as economic and statistic data on fishing, aquaculture and the fish-processing industry. The current guidelines came into effect mid-2017.
Gathering data
The DCF stipulates what data is to be collected, and when the information is to be delivered. Quality criteria have been included. The mandatory collaboration between member-states in collecting and analysing data is also described. This collaboration is organised in regional coordination groups (RCGs) and a commitment to coordinate fisheries-independent data collection with the end-users of said data. The main end-users in the Netherlands are (in addition to the government) ICES (International Council for the Exploration of the Sea), CECAF (Fishery Committee for the Eastern Central Atlantic) and SPRFMO (South Pacific Regional Fisheries Management Organisation).
The data must be collected in all regions where the European fleet operates, even if these regions are outside of European waters. Each member-state draws up a multi-year research programme, detailing what information is to be gathered in what year. The EC then assesses whether the plan meets the DCF requirements. If so, the plan may be executed. At the end of the year, the member-state must submit a technical report detailing what has been achieved.
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WOT-05 projects
Assessment and advice
Justification
Fishery management aims for sustainable exploitation of renewable resources under fair economic and social conditions and with a limited impact on the environment. Management decisions, taken by the European Commission, are always taking scientific advice into account. In fresh waters, national management is delegated to designated Commissions in which representatives of the fishing sector are included. The biological state of the exploited resources, as assessed by scientists, is an important indicator in establishing management measures. Ecosystem considerations are becoming of increasing importance in decisions related to fishery management.
Project
This project includes the provision of assessments of most marine fish stocks which are exploited by the Netherlands inside and outside European waters. The assessments for these stocks are carried out in international working groups and provide the basis for the advice to fishery managers. The project also includes the national contribution to international advisory committees from ICES and STECF. These committees are responsible for providing advice on the management of marine ecosystem and fisheries. Furthermore, on request of the Ministry, support is given to actual management issues of national interest. The project supports development of methods and protocols used in the provision of advice. The main results of the project include the provision of biological advice to fishery management (national and international); contribution to assessments of fish stocks; relevant working papers to international working groups; national reports (and presentations) to the Ministry; contribution to the contents of websites.
Assessment and advice
Justification
Fishery management aims for sustainable exploitation of renewable resources under fair economic and social conditions and with a limited impact on the environment. Management decisions, taken by the European Commission, are always taking scientific advice into account. In fresh waters, national management is delegated to designated Commissions in which representatives of the fishing sector are included. The biological state of the exploited resources, as assessed by scientists, is an important indicator in establishing management measures. Ecosystem considerations are becoming of increasing importance in decisions related to fishery management.
Project
This project includes the provision of assessments of most marine fish stocks which are exploited by the Netherlands inside and outside European waters. The assessments for these stocks are carried out in international working groups and provide the basis for the advice to fishery managers. The project also includes the national contribution to international advisory committees from ICES and STECF. These committees are responsible for providing advice on the management of marine ecosystem and fisheries. Furthermore, on request of the Ministry, support is given to actual management issues of national interest. The project supports development of methods and protocols used in the provision of advice. The main results of the project include the provision of biological advice to fishery management (national and international); contribution to assessments of fish stocks; relevant working papers to international working groups; national reports (and presentations) to the Ministry; contribution to the contents of websites.
Market sampling of marine fish stocks
Justification
The sampling of the structure of catches (landings and discards) provides important information on the state of the fish stocks. The data are used in stock assessments and advice how to manage these stocks. For EU Member States, there is an obligation to sample landings of these stocks according criteria laid down in EU legislation (DCF).
Project
Samples of commercial landings, taken in fish ports or obtained directly from vessels will be taken. A distinction will be made between samples of the length distribution of the landings (mostly measured in fish harbours) and samples for biological parameters (age, length, gender, growth and sexual maturity stage) which are bought and analysed in the fishery laboratory.
The stocks that will be sampled per year can be found in the national work plan for the datacollection framework: Work Plans - European Commission (europa.eu).
Since 2012, sampling of the fishery on stocks outside EU waters has been included in the project. The sampling is conducted by Poland since 2018 under a multilateral agreement between EU Member States involved in those fisheries. The main species sampled are sardinella and horse mackerels in CECAF waters as well as horse mackerels in SPRFMO waters in the Pacific. As of 2025, accreditation is required for EU fisheries observers on board vessels in the Pacific. The Netherlands act as focal point for the accreditation process on behalf of the EU Member states involved in the pelagic fishery in the region, and coordinates the sampling from 2025 onwards.
Results and products
Support and update of the national databases; national data contributions to assessment working groups (age composition of the national catch, age-length keys); annual report of activities; contribution to technical report to EU on national sampling obligations.
Marine research vessel surveys
Justification
Research vessel surveys provide fishery independent information of the stocks in the sea. Information is obtained on the size, structure and distribution of the stocks. Some surveys are designed to obtain estimates of year class strength well before the year class recruit into the fishery. In practice, all information that is obtained (including all bycatches) is sampled. The results of research vessel surveys are used assessments of the state of the fish stocks and the marine ecosystem. All but one surveys in this project are eligible to the DCF.
project: Most of the surveys are carried out in collaboration with other countries and are coordinated by ICES planning groups. The table below provides an overview of the surveys conducted, and of the location where data is stored.
Results and products
Support and update of the national and international databases for survey data; contribution to international coordination of surveys; national data contributions to assessment working groups (survey indices); contribution to MSFD indicators; contribution to a technical report to EU on national survey sampling obligations; contribution to website.
Monitoring by-catches
Justification
This project deals with the collection of discards and incidental bycatches in the Dutch fisheries. Several regulations oblige EU member states to collect information on number of discards and unintended by-catches of megafauna and rare fish species. The project is supportive to data needs in designed format to fish stock assessment and to ad hoc advice to the Ministry and the EU. Even though the Landing Obligation has been phased into the fisheries (in the pelagic fishery in 2015 and in the demersal fishery in 2016-2018), this project will remain essential in validating catch composition, collecting data of incidental bycatches and non-quota species and monitoring exemptions for solely a scientific perspective.
Project
Discard information by self-sampling programmes will be obtained for 180 trips from a reference fleet consisting of vessels from the beam trawl fishery with 80 mm mesh size, including Eurocutters, beam trawl fishery with 100 mm mesh size and the twinrig fisheries on Nephrops and demersal fish. Parallel to this programme ten trips onboard vessels of the reference fleet that are conducting self-sampling will be monitored with observers in order to be able to detect potential biased results of the self-sampling programme. Discard information onboard pelagic trawlers, flyshoot fishery and the passive fishery (i.e. gillnet, handline and fyke fishery) will be obtained through an observer programme. Recording incidental by-catches of megafauna and rare fish species is part of all onboard observer programmes in this project.
Products
Support and update of the national database containing discard data; contribution to international coordination of discard research; national data contributions to assessment working groups; contribution to technical EU reports on discard sampling obligations; (bi-)annual reports with project results, and support and contribute to national and international projects, which are initiated to investigate possible implications of the landing obligation under the CFP.
Fishery Statistics
Justification
Part of the fishery statistics, required by the DCF, are carried out in this project. The project also supports data needs in specific formats to fish stock assessments and to ad hoc advice to the Ministry and the EU.
Project
Continuation of the development of integrated databases with information on national logbook statistics, satellite monitoring data and landing size information from fish auctions. Aggregated data will be made available to ICES and STECF working groups on the relevant spatiotemporal scales. Supportive to the market sampling project, a standardized procedure will be developed for the raising of catch data. In order to comply with the new DCF requirements, several new arrangements (e.g. on the use of individual satellite data and size class statistics) will have to be put in place in order to collect all data required in the DCF framework.
Products
Integration and update of the national fishery statistics database; protocol describing privacy, administration and access to the database; auxiliary procedures for raising, extraction and quality check; support and contributions to EU projects, ICES and STECF working groups; contributions to websites; reports to the Ministry and the EU as required; annual report with key parameters (catch, effort).
Monitoring freshwater fish
Justification
The management of fresh water systems is an area of shared responsibility between the Ministries of LVVN and I&W. To a large extent the national management of fresh waters is framed within international legislation such as European Natura 2000/Habitat Directive, Water Framework Directive and Eel Regulation (nationally translated into Eel management plans, see also ‘Aalonderzoek’).
LVVN is responsible for management of the IJsselmeer and Markermeer. In this project data are collected and analysed in order to provide advice on management of the IJsselmeer and Markermeer. The data collection takes account of the requirements indicated in the above mentioned legislation.
Project
The most important source of information is collected through an open water research vessel survey in the IJsselmeer and Markermeer, a market sampling on board of vessels fishing with seine or standing nets, logbook registrations of fishermen and a sampling programme along the shorelines of these lakes. The surveys provide an assessment of the state of the ecosystem and in particular the fish stocks in these lakes.
The occurrence of salmonids, and other migratory and rare fish species in the IJsselmeer and coastal waters is monitored using fyke catch registrations. A significant part of our monitoring is carried out in close cooperation with commercial fishermen.
Results and products
conducting the field work; support and update of the national database containing fresh water fish data; contribution to website; annual reports with project results.
Eel research
Justification
In 2007 the EU introduced legislation to recover eel stocks in European waters (the ‘Eel Regulation’). In this project research is carried out to monitor the progress of the effect the measures introduced in the Netherlands to restore the eel stock.
Project
A sampling programme is established covering the eel stock in the Netherlands. This sampling programme consists of:
- market sampling of commercial catches, aiming to estimate the size and age composition of the catch;
- glass eel monitoring programme at the main glass eel entries in The Netherlands;
- a monitoring programme of eel in ditches;
- index development to monitor changes in the biomass of silver eel migrating to sea;
- the eel model analysing the eel abundance and fishery and barrier mortality is developed and kept up-to-date.
Results and products
Data are collected in monitoring programmes and stored in national databases. Results are used for the three-yearly evaluation report and for the ICES WGEEL working group.
Monitoring shellfish stocks
Justification
The policy for the management of shellfish stocks in Dutch coastal marine waters is presently based on an integration of fishery-related and ecological objectives. Major elements of management are closed areas, catch quotas and considerations on nutrition needs for birds. Fishing of mussels in tidal areas is only permitted when at least 2000 ha1 of mussel beds are present. Furthermore, management of the bivalve stocks in the Wadden Sea takes into account the agreements of the Trilateral Governmental Conference on the Protection of the Wadden Sea2.
Project
The major elements of the programme are an assessment of the intertidal area covered by beds of blue mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas) in the Wadden Sea, Oosterschelde bay and Westerschelde estuary, of the intertidal stocks of blue mussels, Pacific oysters and cockles (Cesrastoderma edule) in the Wadden Sea, Oosterschelde bay and Westerschelde estuary, of the stocks of American jackknife (Ensis sp.), cut through shell (Spisula subtruncata) and other commercially relevant species in the Dutch coastal zone of the North Sea, of the stocks of mussels, oysters, cockles and other shellfish species in the lakes Veerse Meer and Grevelingenmeer, and of the stock of American jackknife in the subtidal of the western Dutch Wadden Sea. The assessments in all different areas are carried out using research vessels and chartered vessel, and in close cooperation with fisheries inspectors.
The North Sea survey also monitors other benthos species and is part of a time series which indicates considerable changes in the benthic fauna over the period the survey has been carried out.
Results and products
Data collection through surveys; reports with analyses of survey data; maintenance of database; webviewer with survey results support to websites.
1 A ha (hectare) is equivalent to 10,000 square meters
2 Denmark, Germany and the Netherlands
Recreational fisheries
Justification
Sampling of recreational fisheries is an obligation resulting from EU data collection legislation. The present sampling programme is anticipating on the DCF requirement to provide annual estimates of recreational catches (retained and released) of cod, eel, seabass, salmon, pollack, sharks and rays in the North Sea and eel in inland waters.
Project
The Netherlands has concentrated its project towards estimating cod, seabass and eel catches in the recreational fishery. However, the present set up of the project provides also data for other marine and freshwater species. The project has a biennial cycle. Because there is no licence system for anglers in marine water, an online screening survey is carried out every second year to identify the population of recreational anglers. Consequently a subset of the identified anglers (~2500) are selected to join a 12 month diary survey in the following year. The diary survey provides detailed information on catches and fishtrips. In addition a similar logbook survey is conducted among ca. 15-60 recreational gill net fishers since 2014.
Results and products
Database with information on recreational fisheries. Estimates and analyses of data of recreational catches of cod, seabass, salmon, pollack, eel, sharks and rays in the Netherlands.
Dutch Caribbean
Project
Data collection and advice in the Dutch Caribbean for the Dutch Ministry and the governmental institutions on the Dutch Caribbean islands.
Results and products
The results of this project feed into the management of fisheries and vulnerable aquatic (marine) ecosystems in the Dutch Caribbean. Data on commercial fisheries, vulnerable species as sharks and marine mammals as well as coastal ecosystems (mangroves, seagrass fields, coral reefs) are collected within this project in close collaboration with local parties. Data is stored in and made available via the Dutch Caribbean Biodiversity Database. Periodically reporting on the State of nature in the Dutch Caribbean takes place.
Programme management WOT-05 Fisheries Research
Project
The project includes all co-ordination activities which are carried out in WOT programme 05 and the WOT-unit: Centre of Fisheries Research. These activities include the planning, reporting and management of the programme. Also, this project covers DCF coordination activities and meetings. Furthermore, facilitation of the dissemination of information on the programme and the presentation of the programme results to the public through websites is included in this project.
Quality assurance work regarding biological variables is also included under this project as this work constitutes cross-cutting tasks relevant to a number of projects.
Results and products
Planning of research activities and progress reports. National and international coordination, quality assurance biological variables.
Implementation
In the Netherlands, the DCF is implemented by Wageningen Marine Research (WMR) and Wageningen Economic Research (WEcR) by commission of the Ministry of Agriculture, Fisheries, Food Security and Nature (Dutch acronym: LVVN). This responsibility is outsourced to these institutes by the Centre for Fisheries Research (Dutch acronym CVO) and the Centre for Economic Information (CEI). Both WMR and WEcR are part of Wageningen University & Research.
At a national level, the research is coordinated by the national correspondent at the Ministry of Agriculture, Nature and Food Quality, who doubles as the Dutch liaison with the EC for all issues concerning the implementation of the DCF.
Background
In 2000, several European Decrees came into effect, obligating member-states to collect annual economic and biological data on marine fisheries resources and the fishing thereof. These decrees combined, previously called the Data Collection Regulation (DCR), have become known as the Data Collection Framework since 2008.
With the DCF, the EU aims to ensure the member-states collect the data needed to implement the European Fisheries Policy. The DCF stipulates in detail what type of information must be gathered. The information relates to supply and endeavours in fisheries as well as information on bycatch and profits and economic data on fisheries and aquaculture. Moreover, the member states must contribute to international surveys with research vessels.
In 2008, the DCF was expanded to include the mandatory gathering of data on recreational marine fishing and on diadromous fish (salmon-like fish and eels in particular). In 2017 the legislation was updated. This update did not have any far-reaching implications for the Netherlands concerning data collection but is more directive in the way the work is coordinated. For example, through joint funding of fisheries-independent surveys. Moreover, the renewed DCF focuses more on safeguarding the accessibility and quality of the data.
WOT work plan
Marine fisheries research is organised and defined at an international level; this includes statutory fisheries research. The EU Common Fisheries Policy is based on information gathered in this (and other similar) programme(s). Europe has drawn up detailed guidelines (Data Collection Framework, DCF) on what information the member states are required to gather. These guidelines came into effect mid-2017.
The research that member states conduct within the framework of the DCF is described in multi-annual work plans1. A progress report is made annually. The Netherlands submitted a Workplan for 2022-2027 and updated this plan in 2024 for 2025-2027. The updated Workplan was successfully reviewed and approved by the European Commission.
Changes in European legislation may impact the statutory tasks that pertain to this programme. In the 2014 CFP, a discard ban was announced. This ban applies to Dutch pelagic fisheries since 2015 and was further extended to include demersal fisheries between 2016-2018. In 2019, the discard ban was implemented for all TAC-regulated species. Despite the discard ban, sampling bycatch through observer trips and self-sampling remains essential to validate the composition of the catch, collect data on bycatch and non-quoted species as well as monitoring (for scientific purposes) permitted exceptions.
Funding of the EU contribution to data gathering, as stipulated in the national programmes, has been adjusted since 2022 and is coordinated through the European Maritime, Fisheries and Aquaculture Fund (EMFAF).
1Updated Work Plan for data collection in the fisheries and aquaculture sectors 2025-2027.
The Statutory Research Tasks (WOT) Fisheries is one of the six WOT programs of Wageningen University & Research. The Center for Fisheries Research (CVO) studies the development of fish and shellfish stocks in the sea and the IJsselmeer in order to advise the Dutch government on fisheries management. The knowledge is used not only for fisheries advice, but also for the ecological assessment of marine waters. This animation introduces the various research tasks performed by the WOT Fisheries.
Quality Assurance
- Auction sampling commercial demersal fish (AUCTION_DEM)
- Auction sampling eel (ELE-FRS-MIS-commercial fisheries)
- Auction sampling shrimp (AUCTION_SHRIMP)
- Data access permission and responsibilities (Proc_databases)
- Diadromous fish data collection (SAL-FGRZ)
- Fish stomach sampling from demersal research trawl surveys (Stomach)
- Glass eel sampling (ELE-FRS-LNP, ELE-FRS-MPM)
- Hydrographic data from research surveys (Survey_CTD)
- Incidental bycatch monitoring in pelagic commercial fisheries (PETS)
- Recreational fisheries monitoring (REC_self)
- Research surveys acoustic Atlantic (Survey_acou_Atlantic)
- Research surveys acoustic North Sea (Survey_acou_NorthSea)
- Research surveys demersal trawl North Sea (Survey_dem)
- Research surveys ichthyoplankton Atlantic (Survey_plankton_Atlantic)
- Research surveys ichthyoplankton North Sea (Survey_plankton_NorthSea)
- Research surveys shellfish Dutch coast (ENSIS)
- Research surveys shellfish Wadden Sea (MOSKOK)
- Sampling demersal active fisheries through observer trips (DEMACT1)
- Sampling demersal active fisheries through self-sampling (DEMACT2)
- Sampling demersal passive fisheries through observer trips (DEMPAS)
- Sampling pelagic fisheries through observer trips (PEL1)
- Sampling pelagic fisheries through self-sampling (PEL2)
- Seafloor litter sampling from demersal trawl surveys (Survey_litter)
Contact
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