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Report of the Joint EIFAAC/ICES/GFCM Working Group on Eels (WGEEL) 2018

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Auteurs

  • Janis Bajinskis, Laurent Beaulaton, Claude Belpaire, Priit Bernotas, Clarisse Boulenger, Uwe Bramick, Cedric Briand, Andreas Bryhn, Fabrizio Capoccioni, Willem Dekker, Estibaliz Diaz, Isabel Domingos, Malte Dorow, Hilaire Drouineau, Caroline Durif, Derek Evans, Lukasz Giedrojc, Jason Godfrey, Tessa van der Hammen, Reinhold Hanel, Lisa Horn, Katarzyna Janiak, Jesper Kuhn, Chiara Leone, Linas Lozys, JJ Maguire, Lasse Marohn, Tomasz Nermer, Ciara O’Leary, Michael Ingemann Pedersen, Jan Dag Pohlmann, Russell Poole, Jacco van Rijssel, Russell Robertson, Robert Rosell, Argyris Sapoundis, Marcello Schiavina, Eva Thorstad, Rachid Toujani, Alan Walker, Håkan Wickström
  • Claude Belpaire

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Details

Originele taal-2Nederlands
Plaats productieCopenhagen
UitgeverijInternational Council for the Exploration of the Sea (ICES)
VolumeICES CM 2018/ACOM:15.
Aantal pagina's152
StatusGepubliceerd - nov-2018
EventJoint EIFAAC/ICES/GFCM Working Group on Eel (WGEEL) 2018 - Gdańsk, Polen
Duur: 5-sep-201812-sep-2018
http://www.ices.dk/community/groups/Pages/WGEEL.aspx

Abstract

The recruitment of European eel from the ocean remained low in 2018. The glass eel recruitment compared to the 1960–1979 was only 2.1% in the North Sea and 10.1% in the Elsewhere Europe series, based on available dataseries. For the yellow eel dataseries, recruitment was provisionally 29% (not all series fully reported) of the level during the reference period.
Landings data were updated according to those reported to the WGEEL, either through responses to the 2018 Data call or in Country Reports, or integrated by the WGEEL using data from its previous reports. As some countries have not reported all their landings, even the raised versions reported here should be considered as minima.
Glass eel fisheries within the EU take place in France, UK, Spain, Portugal and Italy. Glass eel landings have declined sharply from 1980, when reported landings were larger than 2000 tonnes to 58.6 t in 2018.
Yellow and silver eel landings are not always reported separately, so are combined here. The total landings of yellow and silver eels decreased from 18 000–20 000 tonnes in the 1950s to 2000–3000 tonnes since 2009, and a reported 2224 tonnes in 2017 (mostly Swe-den, Poland, Germany, Denmark, The Netherlands, United Kingdom, France, Italy and Tunisia).
Recreational catches and landings are poorly reported so amounts must be treated as a minimum but were estimated as 2 t for glass eel in 2018 (Spain only), and 161 t for yellow and silver eel combined in 2017 (mostly Denmark and Italy) (2018 data not available at time of writing). Overall, the impact of recreational fisheries on the eel stock remains largely unquantified although landings can be thought to be at a similar order of magnitude to those of commercial fisheries.
Aquaculture production of eel increased until the end of the 1990s but started to decline from the mid-2000s from about 8000–9000 t, and in 2017 the reported quantities of eels produced in aquaculture was 4 546 t, mostly in The Netherlands and Germany. It should be noted that eel aquaculture is based on wild recruits, and part of the production is subsequently released as on-grown eel for stocking (around 10 million eels, which if assuming a mean weight of 20 g would equate to about 200 t).
Restocking data for 2018 were incomplete at time of writing because some restocking programmes were ongoing. An update of the restocking amounts for 2017 suggests about 15 million glass eel, 14 million yellow eels and about 0.5 million silver eels were restocked in 2017, though these amounts include eel moved in the same river basin from where they were first caught (sometimes called assisted migration) and eel on grown in aquaculture.
The WGEEL compiled the biomass and mortality rate stock indicators reported in re-sponse to the 2018 eel data call. The ICES Workshop on Eel Management Plans (WKEMP) will examine these stock indicators in more detail. However, a preliminary analysis by the WGEEL of the data reported by EU Member States found that out of a total of 76 EMUs that most recently reported escapement biomass as a percentage of pristine biomass, 16 (21%, representing six EU countries) are reaching or exceeding the 40% target whereas 60 EMUs are below target.
The WG has made substantial progress in developing the use of the data call and data-base to refine data submission, checking, analyses and reporting. This was the first year of complete data reporting, and the data checking created a large but very worthwhile task. Two workshops are proposed for 2019 to further improve the data call and use of the reported data, and to standardize the analytical approaches used to estimate stock indicators. The data call for 2019 will request updates for recruitment, landings, aquaculture and stocking.
An overview was made of the methods countries use to respond to the data call. Some misinterpretations, inconsistencies and incomplete reporting (life stages, habitats, geo-graphical areas, etc.) were uncovered. The first workshop in 2019 will address these issues.
The WG reviewed developments in previously specified emerging threats and opportu-nities, noting that most of these remained issues to address. New threats included (in no particular order) the effects of high summer water temperature/poor water quality as eel mortalities and disease outbreaks were reported across the UK, Sweden and Estonia; uncertainties over the supply of some glass eel for restocking after the UK leaves the EU; increasing reports of illegal fishing and/or eel trade; increased risk of misreading the age of restocked eel because of artificial ‘annuli’ and its impact on age-based cohort models; and further concern over disease transfer through restocking programmes. New opportunities included technologies to monitor eel behaviour in rivers and at sea; and a new multidisciplinary research project (Sudoang) between Spain, Portugal and France to provide tools and implement joint methods to support conservation of eel and habitats in this region.
The WG recognised that fishing impacts have received most attention in relation to quantifying impacts and effects of management measures. While this will continue, the WG will establish a standing annual activity taking forward quantification of the impacts of non-fishery factors, and to review methods for reducing these mortalities. In 2019, the WG will focus on impacts of hydropower facilities and water pumps.
The Working Group reviewed and trimmed the structure and content of the Country Report, in light of the further refined data call process.
The ToRs for 2019 were drafted according to the multiyear plan proposed in 2016.

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