"The population of the European eel (Anguilla anguilla) has been in severe decline for decades. Although the 30-year downward trend in recruitment of young eel to Swedish waters seems to have halted since 2011, it remains at a historically low level. Our assessment shows that Sweden has made significant progress in reducing human impact on eels in its coastal waters. However, the human impacts on eel in inland waters remain too high, and this requires more action," says Rob van Gemert, researcher at the Department of Aquatic Resources at SLU.
Human activities – the major threat to the European eel
The European eel has an intricate lifecycle. They reproduce in the Sargasso Sea in the Atlantic Ocean, from where their larvae drift with the currents towards European shores. Once there, they either remain in coastal waters or seek out freshwater, where they grow for a number of years (or even decades), before migrating back to the Sargasso Sea, to spawn and complete their lifecycle.
During their continental phase, eels face numerous human-induced pressures, including fishing, hydropower turbine mortality, pollution, habitat loss, and effects of climate change. These combined pressures have led to a significant decline in European eel populations across Europe, prompting the EU to implement strict regulations in 2007. Member states, including Sweden, were mandated to develop and implement national Eel Management Plans.
SLU’s latest report evaluates the current status of the Swedish eel stock and the anthropogenic pressures on it, relating these findings to the goals and limits stipulated in EU Eel Regulation and the Swedish Eel Management Plan. The report offers a comprehensive overview of the current status and pressures affecting the European eel in Swedish waters.
Key findings:
Inland Waters
Silver eel* production has drastically declined, from over 700 tonnes per year in 1960 to below 300 tonnes in 2023. Currently, over 90 % of inland silver eel production consists of imported eels that have been released in Swedish waters as glass eels (so-called restocking). Human impacts, particularly from hydropower and fisheries, have severely hampered silver eel escapement from Swedish inland waters. In 2023, only 84 out of 282 tonnes of silver eel were estimated to be able to reach the sea, with significant losses due to fishing and turbine mortality. This far exceeds the mortality limit needed for recovery, necessitating a reassessment of current inland water management strategies.
West Coast
The commercial fishery for yellow eel* was stopped in 2012, leading to a noticeable recovery of the yellow eel population. Nevertheless, recruitment of young eel to the West Coast remains around a historic low, limiting the extent of the recovery potential. Furthermore, due to a lack of sufficient data, the absolute biomass of the West Coast stock remains unquantifiable
Baltic Coast
The impact of the Swedish coastal fisheries on the escapement of silver eel from the Baltic Sea has greatly decreased and is currently estimated to be minimal, with the 2023 mortality estimated at only 0.3%. However, the status and production of silver eel from the Swedish part of the Baltic Sea remains unknown. The report therefore calls for a coordinated, integrated assessment with other Baltic countries to accurately assess and mnage the eel population across the whole Baltic Sea region.
Revision of the Swedish eel management plan
The Swedish Eel Management Plan will be revised in 2025. This new report calls for a comprehensive revision of the Swedish Eel Management Plan using the latest insights and available data. The upcoming revision of the Swedish Eel Management Plan should define clear targets for biomass and limits for anthropogenic mortality, to facilitate the recovery of the European eel in Sweden. Additionally, the development of a comprehensive, integrated assessment for the entire Baltic Sea eel stock in collaboration with other Baltic countries is essential for effective management.
“For the eel in inland waters the situation is most critical. The main source of human-induced mortality for eel in inland waters is fishing and hydropower turbines, responsible for an estimated silver eel mortality of 82 and 115 tonnes respectively in 2023, so reducing those numbers should be one of the main priorities for the inland eel management”, says Rob van Gemert.
Link to full report:
Assessment of the eel stock in Sweden, spring 2024 : fifth post-evaluation of the Swedish eel management (Aqua reports 2024:5)
