Institute of

Fisheries Ecology

The economic impacts of European eel conservation versus sustainable use

Recruitment of eel has been in decline for more than three decades and despite several protection measures, which have already been established, the stock is considered to be outside safe biological limits. The project aims to assess the effectiveness and efficiency of management measures and to identify relevant actors for the further development of the European eel population.

Background and Objective

The European eel (Anguilla anguilla) stock has been in steep decline since more than three decades and glass eel recruitment decreased to less than 10 % of the 1960 – 1979 average, intermittently dropping to less than 1% in the North Sea. Several protection measures for eel have been established, including listing on Annex II of CITES and the EU-Regulation 1100/2007, which obliges the EU Member States to establish Eel Management Plans for their waters. Despite these efforts, the stock is still in a critical state. In addition, while there are regular reports on the status of the stock by international scientific groups, the socioeconomic significance, exploitation and the economic actors are much less documented. Therefore, the European Parliament’s Committee on Fisheries requires useful, authoritative and timely information on the reproductive biology, migration and sustainable management of the European eel.

Numerous factors are being discussed as the possible cause for the decline of the stock, e.g. fisheries, habitat loss, environmental pollution, parasitism, diseases or climate change and changes in oceanic conditions. With all life stages being commercially exploited at sometimes unsustainably high levels and an extensive loss of natural habitats across Europe, fisheries and water constructions are amongst the most notable anthropogenic impacts during the continental life of European eels.

Due to a still incomplete understanding of the life cycle of the European eel, it has proven difficult, however, to pinpoint the exact cause for the decline of the stock. There is a rather general consensus that it was caused by the interplay of several factors acting on regional and global scales and different life stages. This complexity renders the management of the European eel an extremely challenging task.

It is thus the primary objective of this study to utilize all available information and collect additional data in order to identify relevant stakeholders associated with the European eel stock and investigate the complex interactions between economic actors and conservational efforts on both, national and international levels and evaluate the effectiveness, sustainability and economic viability of management measures.


Together with international partners, experts of the Thuenen-Institutes of Fisheries Ecology and Sea Fisheries will provide a comprehensive overview on biology, stock status and management of the eel stock with a special focus on the socioeconomic dimensions including assessment of the socioeconomic repercussions of potential management and protection measures to the stakeholders. For this purpose, we will address the following questions:

  1. Provide an up-to-date overview on biology and stock status, especially for all aspects relevant for spawner escapement and sustainable management of the species.
  2. Which measures have already been established in the EU member states and how effective can these measures be? Who are the responsible institutions and authorities?
  3. Who are the main economic actors impacting the eel stock during its different life stages?
  4. What are the main types of industrial installations affecting the migration of eel and what is their socioeconomic importance?
  5. How strong do the main economic actors affect the eel stock and how strong do they depend on the species?
  6. What will be the effects of several management and protection measures on the stakeholders?

The first tasks will be tackled based on available peer reviewed and grey literature. We will also use our extensive scientific and institutional networks to gather and collate the most recent information for all relevant life history stages (oceanic larvae, glass eels, yellow eels, silver eels) in their respective habitats (oceanic, coastal, continental) throughout their whole range of natural distribution. However, as there is a lack of information for the economic and socioeconomic aspects, new data will be gathered during the project. Following the structure of the project and the questions to be addressed, there will be several outcomes of the study:

The project will provide a comprehensive overview on the biology of the species, including the important aspect of migrations, and on anthropogenic factors affecting the eel stock. It will further provide an overview about the management and protection measures established in the EU Member States and a rough assessment of the effectiveness of these measures. We will further identify the main actors (fisheries and non-fisheries) affecting the eel stock and quantify their impact. In turn, we will also try to analyse the dependency of the stakeholders on eel. Based on this information, the study will attempt to assess the repercussions of several potential management and protection measures on the main stakeholders. The study will also indicate gaps in knowledge and information, hence potentially forming a starting point for the development of future research. As a result, the study will deliver useful and necessary information for the decision process aiming at recovery and sustainable use of the eel stock. The outcomes will be disseminated widely using different ways and fora to reach all relevant stakeholders.


Based on the available economic data on cost structures of eel fishers that carry out commercial fisheries (marine and freshwater) only a vague analysis of impacts is yet possible. Accordingly, the loss of direct revenues at a total closure of eel fisheries in Europe (glass, yellow and silver eels) is estimated to EUR 50 million per year. The most severe economic impacts may be caused by a closure of the glass eel fishery, since, as a secondary effect, the loss of seed would also result in a cessation of European eel aquaculture, with losses of EUR 37 million in revenues, and, consequently, to a large extent also of fish processing companies specialised on eel.

The putative costs to mitigate hydropower mortalities exceed the loss of revenues for a total closure of fisheries in Europe by far.

In order to improve the efficiency and coordination of implemented measures and to enable a proper stock management the following actions are recommended:

  1. The EU Regulation needs to be changed towards a mortality target instead of the current 40% regional level escapement targets. However, such a mortality target needs to be sufficiently low to further reduce direct anthropogenic impacts on the stock.
  2. Eel mortality at hydropower plants needs to be assessed according to the individual characteristics of installations. Effort is also needed to assess the efficiency of mitigation measures at barriers (e.g. bypasses, trap-and-transport) to enable an effective coordination of the implementation of these measures.
  3. Given the unknown efficiency of mitigation measures at barriers, the transport of eels to areas upstream of obstacles should be ceased. Bypasses and trap-and-transport are beneficial, but should not justify the continuation of eel stocking programmes upstream. Instead, pressure should be maintained to fully restore river continuity.
  4. The value of stocking as a management action in many Eel Management Plans needs to be critically evaluated. When stocking to increase silver eel escapement and thus aid stock recovery, an estimation of the prospective net benefit should be made prior to any stocking activity. Stocking should take place only where survival to silver eel escapement is high, and should not be used as an alternative to reducing anthropogenic mortality.
  5. Accordingly, the effectiveness of all management actions listed in the EU Regulation and in national Eel Management Plans needs to be assessed and quantified. The implementation of mitigation measures generally needs scientific guidance, proper monitoring and ex-post-evaluation.
  6. The coordination among different management levels (regional, national, European and sectoral) needs to be improved. A lack of coordination between management levels can impair the effect of single management actions.
  7. A collection of economic data is urgently needed for companies involved in eel fisheries (especially in inland and estuarine waters). Economic data are required to assess the economic importance of eel for fisheries and small processing companies. With sufficient data, including the whole value chain (including fisheries, aquaculture, fish processing and trading companies) an economic impact assessment could test effects of e.g. a total closure of the fisheries.
  8. An international traceability system for glass eels needs to be implemented to follow the fate of legal catches within and among countries and to detect illegal catches. It is also important that regional and national enforcement agencies control illegal eel fishery.


Involved Thünen-Partners

Involved external Thünen-Partners

  • Profundo
    (Amsterdam, Niederlande)
  • Azti-Tecnalia
    (Sukarrieta, Spanien)
  • EPTB Vilaine
    (La Roche Bernard, Frankreich)
  • Fisheries Research Institute of the Hellenic Agricultural Organization “Demeter”
    (Kavala, Griechenland)

Funding Body

  • European Union (EU)
    (international, öffentlich)


7.2018 - 2.2019


hits: 2

  1. Biseau A, Diaz E, Beaulaton L, Boughaba J, Briand C, Cardinale M, Ciccotti E, Dekker W, Domingos I, Drouineau H, Durif CM, Evans D, van Gemert R, Gollock M, Hammen T van der, Hanel R, Kaifu K, Janiak K, O’Leary C, Pohlmann J-D, et al (2021) Workshop on the future of eel advice (WKFEA). Copenhagen: ICES, 67 p, ICES Sci Rep 3(13), DOI:10.17895/
    pdf document (limited accessibility) 998 kb
  2. Hanel R, Briand C, Diaz E, Döring R, Sapounidis A, Warmerdam W, Andres M, Freese M, Marcelis A, Marohn L, Pohlmann J-D, Scharrenburg M van, Waidmann N, Walstra J, Werkman M, Wilde Jde, Wysujack K (2019) Research for PECH Committee - Environmental, social and economic sustainability of European eel management. Brussels: European Parliament Policy Department for Structural and Cohesion Policies, 187 p, DOI:10.2861/033620