HERRING : An analysis of spawning ground management, ecological conditions and human impacts in Greifswald Bay, Vistula Lagoon and Hanö Bight.

This book compiles the findings of the HERRING project which was conducted from 2012 until 2015 and part-financed by the EU South Baltic Programme. The main objective of the HERRING project is to improve the consideration of including herring spawning grounds in coastal management. Herring as a resource recourse would be part of the economic development of coastal areas, and HERRING strongly emphasizes the importance of foster an integrated coastal management in the South Baltic Sea. Three case study areas in Germany, Poland and Sweden serve as the basis of the approach, which can be roughly distinguished in two parts. The analysis of the ecological parameters and conditions as well as the impacts of present and future human activities, spatial uses and natural changes The analysis and compilation of the multi-level institutions and manage- ment instruments that govern the use and protection of coastal herring spawning grounds. The management of coastal spawning areas can function as an example to show the huge diversity of interest, demands and actors that need to be considered for the sustainable use of resources and ecosystems.https://commons.wmu.se/mer_book/1002/thumbnail.jp

REPORT OF THE JOINT EIFAAC/ICES/GFCM WORKING GROUP ON EELS (WGEEL)

The Joint EIFAAC/ICES/GFCM Working group on eels (WGEEL) met in a split meeting from 4–8 September (online) and 25 September–02 October 2023 (hybrid meeting) in Helsinki, Finland, to provide the scientific basis for the ICES advice on fishing opportunities and conservation as-pects for the European eel and address requests from EIFAAC and GFCM. WGEEL assessed the state of the European eel and its fisheries, collated and analysed biometric data, reviewed the implementation of the WKFEA (Workshop on the future of eel advice) roadmap, examined available recruitment data from coastal and marine habitats, reported on any updates to the scientific basis of the advice, new and emerging threats or opportunities, in-cluding developments in the Mediterranean region. After high levels in the late 1970s, the recruitment declined dramatically in the 1980s and remains low. Compared to 1960–1979, the recruitment in the “North Sea” was 0.4% in 2023 (provisional) and 0.7 % in 2022 (final). In the “Elsewhere Europe” index series was 8.8 % in 2023 (provisional) and 11.3% in 2022 (final). For the yellow eel data series, recruitment for 2022 was 9% (final). Time-series from 1980 to 2023 show that glass eel recruitment remains at a very low level, with an historical minimum value in the North Sea. Silver eel time series have been analysed to identify patterns in abundance trends. These analyses are exploratory and have enabled us to test certain statistical methods and their limitations for analysing temporal series on silver eels. Although they give us an initial idea of trends in silver eel abundance, their results should be treated with caution. In fact, several problems have been identified and these points need to be improved in order to be able to interpret the results. The trend of reported commercial landings shows a long-term continuing decline, from a level of around 10,000 t in the 1960s, reported commercial landings have now dropped to 2028 (glass eel + yellow eel + silver eel) in 2022. The commercial glass eel fishery in 2022 was 60.1 t and 53.6 t in 2023. Reported landings from yellow and silver eel commercial fisheries (Y, S, YS) add up to 2914 t in 2021 and 2437 t in 2022. Spain was the only country allowing a recreational catch of glass eel, with landings estimated at 0.72 t in 2022 and 1.32 t in 2023. Reported recreational land-ings for yellow and silver eel combined were 240 t for 2021 (11 countries reporting) and 249 t for 2022. Progress with regards to the ‘road map’ developed within WKFEA was evaluated. The returns from the three questionnaires distributed by WKSMEEL to WGEEL members were summarised. In relation to the progress of the WKFEA roadmap, item 1; the inclusion of biological data is advanced with biometry data included in the annual data call. Item 2 relates to the reconstruction of the landings data and a workshop will take place in December 2023. Items 3 and 4 are also in progress, the Spatial database and Model for Eel (WKSMEEL) workshop was held in June 2023 with a follow up workshop planned for October 2023. A questionnaire for 3 topics (electrofish-ing, hydrographic network, and river obstructions & hydropower) was circulated to WGEEL members in August 2023. Of the 21 countries who responded, a large majority carry out electro-fishing, have available hydrographic networks and hold some information of obstructions to migration. However, it was recognised that considerable effort and resources will be required before the available data could be collated.publishedVersio

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

The Joint EIFAAC/ICES/GFCM Working group on eels (WGEEL) met in a split meeting from 4–8 September (online) and 25 September–02 October 2023 (hybrid meeting) in Helsinki, Finland, to provide the scientific basis for the ICES advice on fishing opportunities and conservation aspects for the European eel and address requests from EIFAAC and GFCM.WGEEL assessed the state of the European eel and its fisheries, collated and analysed biometric data, reviewed the implementation of the WKFEA (Workshop on the future of eel advice) roadmap, examined available recruitment data from coastal and marine habitats, reported on any updates to the scientific basis of the advice, new and emerging threats or opportunities, including developments in the Mediterranean region.After high levels in the late 1970s, the recruitment declined dramatically in the 1980s and remains low. Compared to 1960–1979, the recruitment in the “North Sea” was 0.4% in 2023 (provisional) and 0.7 % in 2022 (final). In the “Elsewhere Europe” index series was 8.8 % in 2023 (provisional) and 11.3% in 2022 (final). For the yellow eel data series, recruitment for 2022 was 9% (final). Time-series from 1980 to 2023 show that glass eel recruitment remains at a very low level, with an historical minimum value in the North Sea.Silver eel time series have been analysed to identify patterns in abundance trends. These analyses are exploratory and have enabled us to test certain statistical methods and their limitations for analysing temporal series on silver eels. Although they give us an initial idea of trends in silver eel abundance, their results should be treated with caution. In fact, several problems have been identified and these points need to be improved in order to be able to interpret the results. The trend of reported commercial landings shows a long-term continuing decline, from a level of around 10,000 t in the 1960s, reported commercial landings have now dropped to 2028 (glass eel + yellow eel + silver eel) in 2022. The commercial glass eel fishery in 2022 was 60.1 t and 53.6 t in 2023. Reported landings from yellow and silver eel commercial fisheries (Y, S, YS) add up to 2914 t in 2021 and 2437 t in 2022. Spain was the only country allowing a recreational catch of glass eel, with landings estimated at 0.72 t in 2022 and 1.32 t in 2023. Reported recreational landings for yellow and silver eel combined were 240 t for 2021 (11 countries reporting) and 249 t for 2022.Progress with regards to the ‘road map’ developed within WKFEA was evaluated. The returns from the three questionnaires distributed by WKSMEEL to WGEEL members were summarised. In relation to the progress of the WKFEA roadmap, item 1; the inclusion of biological data is advanced with biometry data included in the annual data call. Item 2 relates to the reconstruction of the landings data and a workshop will take place in December 2023. Items 3 and 4 are also in progress, the Spatial database and Model for Eel (WKSMEEL) workshop was held in June 2023 with a follow up workshop planned for October 2023. A questionnaire for 3 topics (electrofishing, hydrographic network, and river obstructions & hydropower) was circulated to WGEEL members in August 2023. Of the 21 countries who responded, a large majority carry out electrofishing, have available hydrographic networks and hold some information of obstructions to migration. However, it was recognised that considerable effort and resources will be required before the available data could be collated

2020 Report of the EIFAAC/ICES/GFCM Working Group on Eels (WGEEL)

The Joint EIFAAC/ICES/GFCM Working group on eels (WGEEL) met by correspondence and video conference from September 21–28 in 2020 to assess the state of the European eel, investigate the effects of habitat loss on the eel stock and its management, review and update the Stock Annex, prepare the 2021 Data Call and report on any updates to the scientific basis of the advice, new and emerging threats or opportunities. Furthermore, data on fisheries landings, aquaculture and restocking are presented. Analyses were carried out on two glass eel recruitment indices (comprising 28 time-series in the Elsewhere Europe area and 24 time-series in the North Sea) and one yellow recruitment index (comprising 16 time-series). Note, that some data from the current year are always provisional to allow for a small proportion of late reporting series, but this is not considered to materially affect the trends. The potential impacts of COVID-19 on the data collection and quality were noted by the WG and described in detail in the report. The recruitment of European eel strongly declined from 1980 to 2011. The glass eel recruitment compared to that in 1960–1979 in the “North Sea” index area was 0.5% in 2020 (provisional) and 1.4% in 2019 (final). In the “Elsewhere Europe” index series it was 6.5% in 2020 (provisional) and 5.6% in 2019 (final), based on available dataseries. For the yellow eel dataseries, recruitment for 2019 was 17% (final) of the 1960–1979 level; the 2020 data collection for yellow eel is ongoing. Statistical analyses of the time-series from 1980 to 2020 show that recruitment has stopped decreasing in 2011 but the trend thereafter is rather unclear. A Bayesian assessment model (GEREM), structured to allow the existence of potential different trends among regions, and provide absolute recruitment per zone has been run. While still preliminary, this model confirms the trend in recruitment, points out the need of new time-series of recruitment, and could in the future allow a part of the analytical assessment of the stock. The collection of yellow and silver eel series and their biometric data, started last year, has continued and a first analysis has been run. There is a large spatial variability in trends of abundance among locations but the analysis of the long-term time-series shows that current silver eel abundance is low when compared to the pre-1980 levels. The analysis of biometric data allows a first analysis of the biological characteristics of the series and points out missing fields in data collection. Emerging threats and opportunities that have been reported over the past decade were reviewed, and diseases, parasites, contaminants and hydropower were identified as routinely reported and thus established. Climate change was repeatedly reported in the past; yet knowledge remains limited. Moreover, the threat of the EU exit of the UK raised concerns regarding the accessability of glass eels for stocking and the potentially increased availability of glass eel from the UK being traded illegally to Asia The issue of COVID-19 was addressed and impacts were found to fall largely in three categories: i) scientific monitorings, ii) restocking programmes and iii) closures/delays in commercial fishing and loss of markets. The WG has a new standing annual activity to examine quantification of the impacts of nonfishery factors and in 2020 i) reviewed the literature on the effects of habitat loss with a focus on the biological processes operating, ii) the national Eel Management Plans and (latest) triannual assessments identifying whether and to what extent the effects of habitat loss have been taken into account, iii) develop a workplan aiming at the quantification of habitat loss and its effect on eel production in the coming years, and iv) present a number of actual case studies. Due to the lack of appropriate data, a meaningful quantitative assessment is not possible at the moment. Overall, the working group has made progress towards the assessment of the standing stock and spawning–stock biomass (i.e. yellow and silver eel time-series) and the implementation of an additional model for the recruitment data provides towards further analyses (e.g. with respect to regional differences). The WG identified relevant issues for future research, highlighting the limited knowledge on the complex effects of climate change as well as the need for additional and specific data collection to quantify the effects of habitat loss