BioConsult GmbH & Co. KG (Bremen) has announced a new project that began in early 2026:

BeFisch – Conservation of endangered fish species (Project code: 3525520200)

The project will run for three years (2026–2029) and is funded by the Federal Agency for Nature Conservation (BfN, Vilm).

https://www.bfn.de/projektsteckbriefe/bestandsfoerderung-von-gefaehrdeten-fischarten-befisch

Reintroduction Plan for the North Sea Houting

The aim is to develop a concrete reintroduction plan for the North Sea Houting, building on the feasibility study by Schulze et al. (2025). As a first step, gaps in knowledge are to be addressed and information on the current population status of the North Sea Houting is to be compiled.

The focus is on four potential reintroduction watercourses:

  • Wümme,
  • Oste,
  • Treene and
  • Stör.

Factors to be assessed include habitat quality, passability, spawning and rearing areas, and the predator situation. In the Treene, practical investigations are also planned, including the tagging of spawning fish and the recording of larvae and juvenile fish.

This will be supplemented by watercourse mapping and consultation with national and international experts.

The reintroduction plan is to include specific proposals for measures to improve passability and habitat quality, as well as for stocking.

Other migratory fish species and the aquatic ecosystems as a whole will also benefit from the planned measures to improve passability and habitat quality.

Involvement of all stakeholders

The project relies on the close involvement of all stakeholders. The aim is to work together to create the conditions for a successful reintroduction.

Contact

Sandra Schulze
schulze@bioconsult.de
Telefon:  +49 (0)421 694981 – 23

Feasibility study

Schulze, S., Christiansen, T., Scholle, J., Nobis, G., & Schuchardt, B. (2025). Wiedereinbürgerung des Nordseeschnäpels (Coregonus oxyrinchus) in deutschen Nordseegewässern. Machbarkeitsstudie. BfN-Schriften 713. Bundesamt für Naturschutz, Bonn Download

Confusion regarding the taxonomic classification of the North Sea houting

Schulze et al. (2025) write on this subject:

“(…) there has long been scientific disagreement regarding the species’ classification. On the one hand, it is possible that

  • C. oxyrinchus historically occurred only in the Rhine and to the west of it and has been extinct since around 1940, and that all houting populations in the North Sea east of the Rhine and in the Baltic Sea were and are classified as C. maraena (see in particular Freyhof and Schöter 2005).
  • On the other hand, it is possible that the historical houting populations, which were widespread particularly in the Wadden Sea and its associated estuaries (and which also largely disappeared around 1940), were (or are) (also) classified as C. oxyrinchus or at least as a distinct ‘Evolutionarily Significant Unit’ (ESU) (Waples 1991) (Jepsen et al. 2012, Jensen et al. 2015, Winter 2017).”

Presentation in the GfI Fish Species Atlas

Both “species” are presented in the GfI Fish Species Atlas, with the classification as C. maraena on the one hand or C. oxyrinchus on the other following the information in the cited literature sources. This results in an unsatisfactory, confusing situation. From the perspective of the Atlas editorial team, it would be desirable if the project announced here were to bring clarity to this now long-standing expert debate.

Source: GfI Fish Species Atlas

Houting Coregonus oxyrinchus https://biodiv-atlas.de/fische/#!/species/40110/details

Houting (Maraenae) Coregonus maraena https://biodiv-atlas.de/fische/#!/species/40109/details

Background photo: Houting from river Weser Rechtenfleth 26.07.2018, km 45 (Photo: BioConsult). Source: Schulze et al. (2025).