Herwigstraße 31

27572 Bremerhaven

Telephone: +49 471 94460 101

Fax: +49 471 94460 199

UFOs in the North Sea ...


"Nr. 5 lebt": Opto-akustische Einheit des UFO (c) Thünen-Institut/Joachim Gröger
Die Opto-akustische Einheit des UFO weist Ähnlichkeiten mit dem Filmroboter "Nr. 5" auf. (© Thünen-Institut/Joachim Gröger)

Development of a non-invasive, acoustic-optic underwater fish obsvervatory (UFO)

Climate change, fisheries, and several other factors affect marine ecosystems in many ways. To capture its dynamics in a better way, we develop a technically innovative underwater fish observatory at the Thünen Institute of Sea Fisheries.

Background and Objective

We aim at capturing fish and their natural environment synoptically, at a high resolution, continuously and non-invasively in an automated fashion. The data acquisition is even possible where research vessels cannot go to or where these are prohibited (wind farms, protected areas, mariculture, gillnet areas, etc.). With the data obtained, the dynamics and the state of the captured fish populations can be analysed, the size of stocks be calculated and the fisheries be managed.

The initially stationary UFO monitoring system combines advanced optical and acoustical sensor technologies. The synchronized mechanism works in an event-based manner: A highly sensitive sonar system sends out acoustic pings that detect passing objects such as ships, whales, seals or fish. If it is fish, the sonar creates special acoustic recordings (echograms), that will be blended with synchronously generated photo sequences taken by extremely light sensitive (“low light”) stereo underwater cameras. Simultaneously, the species, size and distance of fish are automatically determined; other quantities, such as the volume, weight or age of fish may be derived from these. Other sensors for measuring environmental parameters are also turned on. In this way, we create complex data sets for the quantitative assessment and modelling of fish populations, so that labour-intensive, costly and stocks influencing samples (catches) can be reduced.

For areas where static UFOs cannot be used, a mobile version shall be developed later, which will be "linked" with the static variants and that can communicate with these. Both systems can be integrated into a decision-making system, a so-called "decision support system", to facilitate decisions and by this supporting the management of fish stocks.

Opto-akustische Einheit des UFO
Die Opto-akustische Einheit des UFO weist Ähnlichkeiten mit dem Filmroboter "Nr. 5" auf. (© Thünen-Institut/Joachim Gröger)
UFO während des Aussetzens in der Kieler Förde
Das Unterwasser-Fisch-Observatorium (UFO) während des Aussetzens bei einem Test in der Schwentine-Mündung der Kieler Förde. (© Thünen-Institut/Sven Hammann)

Target Group

science, politics


We expect high-resolution, continuous and synchronous time series on various characteristics, behavioural patterns and statistical quantities of fish stocks and their environment recorded by the UFO system that will allow us an objective and thorough assessment of the state of fish stocks and that of the environment. In addition, statements about the influence of e.g. climate change, fisheries activities and other anthropogenic factors such as wind farms or the establishment of protected areas can be made. Many UFOs being deployed in key areas will allow us inferring statements on all facts and conditions as mentioned above. In this way, we will achieve assured analysis results, that have the potential to facilitate the upcoming decision-making process and foster sustainable management. Due to its design, the UFO system plus the information gained by it can be thought of as being a part of a broader "Decision Support System".

Links and Downloads


Involved Thünen-Partners

Involved external Thünen-Partners

Funding Body

  • Federal Ministry of Food und Agriculture (BMEL)
    (national, öffentlich)


7.2013 - 6.2015

More Information

Projekt type:
Project funding number: 313-06.01-28-1-28-1-91.007-12
Funding program: Innovationsförderung
Project status: finished

Dateien zum Projekt

  • Flyer zum UFODieser Flyer bietet eine kurze Zusammenfassung über das Unterwasser-Fisch-Observatorium.
  • Präsentation UFODie Präsentation des UFOs gibt eine Zusammenfassung und Vorstellung des Projektes mit Stand Oktober 2014 wieder.
  • Pressemitteilung UFODie Pressemitteilung des Thünen-Instituts vom 20.02.2014 zum UFO-Projekt. Dieses Unterwasser-Fisch-Observatorium ist ein nicht invasives, automatisches Monitoringsystem zur Überwachung von Fischbeständen.