Twenty years of protecting eels in Rhineland-Palatinate

Eels have been caught in the Mosel and Saar rivers as a conservation measure for 20 years now. Although it sounds paradoxical, the effort is part of the State of Rhineland-Palatinate’s initiative to protect the animals. The initiative, which is supported by the Landesamt für Umwelt (State Office for the Environment), the Struktur- und Genehmigungsdirektion Nord (Structure and Licensing Directorate North) and innogy SE, has been running for two decades.

To mark the occasion, the technical report “20 Jahre aktive Partnerschaft für den Aal an Mosel und Saar” (20 Years of Proactive Partnership Conserving Eels on the Mosel and Saar) was presented today, underscoring the success of many of the initiative’s measures. The initiative minimises the impact of hydroelectric power plants on fish and increases eel stocks. The guiding principle is to balance ecological and economic concerns in order to ensure climate-friendly electricity supplies generated by hydro power plants. As part of the initiative, eels in the Mosel and Saar rivers (those sections located in Rhineland-Palatinate) are caught in traps upstream of hydroelectric plants in order to release them elsewhere along the river. This enables up to 15,000 eels to migrate to their spawning grounds in the Sargasso Sea, unimpeded by power plant turbines.

“There were many reasons for Rhineland-Palatinate, which holds fishing rights on the Rhine, Mosel and Saar, to sign an agreement with RWE in 1995,” explains Dr Stefan Hill, president of the State Office for the Environment. “No feasible technology existed to prevent harm to eel stocks by hydro power turbines on the Mosel and Saar. The declared goal was therefore to work with the power plant operator to find a cooperative and financially secure method of implementing best practices for preventing and reducing harm to fish. Compensation payments alone would not have solved the problem.”

Dr Holger Himmel, director of the Renewable Energies division at innogy SE
“Hydroelectric power has been used for over 100 years to generate green electricity – reliably and economically. The initiative for protecting eels is a model project that has also been around for quite some time. And it is one we care deeply about, since we take our responsibility seriously as operator of the ten hydro plants on the Mosel. For example, we adjust operations at the facilities to reflect the times when eels are migrating. We would also like to express our sincere thanks to the State of Rhineland-Palatinate and our project partners at research institutes and in the fishing industry for the many years of close cooperation. May the partnership continue for a long time to come.”
Dr Holger Himmel, director of the Renewable Energies division at innogy SE

As part of the agreement, innogy has made approximately €2.4 million available for the eel-conservation initiative since 1995 and has supported the related working group in analysing the project findings. With the support of a principal partner, the Institute of Hydraulic Engineering and Water Resources Management at RWTH Aachen University, the findings have been included in the technical report. “The report impressively shows the multifaceted efforts that have been carried out in the last 20 years to ensure effective protection of eels in the Mosel,” says Professor Holger Schüttrumpf of RWTH Aachen University.

New transport containers were also presented during the anniversary ceremony. They will be used to transfer the caught eels to an area on the Rhine near the town of Rolandseck, after which they can continue their journey unhindered. “Since 1997, ten professional fishermen have been using hundreds of traps to catch migrating eels on the Mosel and Saar between the months of July and November. They are collected every week in special transport containers. The new containers are better insulated so that the eels are not exposed to excessive temperatures even when it is hot. They are then released in the river at the appropriate spot, unharmed,” explains professional fisherman Toni Kröber.

Migration of eels

A highly endangered species, the European eel has been put on the Red List of the International Union for Conservation of Nature (IUCN), designating it as threatened with extinction. According to the latest research, there are a number of reasons why stocks are currently declining, such as changes in the Gulf Stream, overfishing of young eels off the coast of Europe and in inland waterways, and the harm caused by hydroelectric power plants. Eels are part of the natural ecosystem in the Mosel and Saar, where they grow to maturity before migrating to the North Sea and on to the Sargasso Sea. They begin their journey when certain environmental conditions occur relating to runoff levels, water temperature and turbidity. The eels spawn in the Sargasso Sea and the hatched larvae move with water currents to reach Europe. Some continue migrating into inshore waters and some are caught – in particular in river estuaries on France’s Atlantic coast and along the River Severn in the UK – and brought to inland areas suitable for their growth. This includes the Mosel and Saar, where they mature and begin migrating downstream after approximately ten years.

The Rhineland-Palatinate initiative for eel conservation

In order to reduce the harm done to eels by turbines at hydroelectric power plants, RWE (now innogy SE) established a partnership with the State of Rhineland-Palatinate and professional fisherman in 1995. Taking into account the interests of fisheries and operators of hydro power plants, the initiative explores new, effective methods of eel conservation. To do so, it carries out a range of activities.