Are there UFOs 5

UFOs in the North Sea or "No. 5 lives" ...


Development of a non-invasive, acoustic-optical underwater fish observatory (UFO)

Climate change, fisheries and a number of other factors influence marine ecosystems in a variety of ways. In order to better capture their dynamics, we are developing a technically innovative underwater fish observatory at the Thünen Institute of Sea Fisheries.

Background and purpose

We strive to record fish and their natural environment in an automated manner in a synoptic, high-resolution, continuous and non-invasive manner. Data collection is even possible where research vessels cannot or are not allowed to go (wind farms, protected areas, mariculture, fixed net areas, etc.)

The data obtained in this way can be used to analyze the dynamics and condition of the recorded fish populations, calculate the size of the stocks and manage the fishery. In the initially stationary UFO monitoring system, we combine the most modern optical and acoustic sensor technologies. The synchronized mechanism works on an event basis: A highly sensitive sonar system sends out acoustic ping signals that detect objects such as ships, whales, seals or fish swimming by. In the case of fish, the sonar creates special acoustic recordings (echograms), which we combine with synchronously generated photo sequences from extremely light-sensitive stereo underwater cameras. At the same time, the type, size and distance of the fish are automatically determined, from which further parameters such as volume, weight or age can be derived. Additional sensors for measuring environmental parameters are also switched on. In this way, we generate complex data sets for the quantitative recording and modeling of fish populations, so that labor-intensive, cost-intensive and stock-influencing sample catches can be reduced.

For areas in which static UFOs cannot be used, a mobile variant is to be developed later that will be "networked" with the static variants, that is to say can "talk" to them. Both systems can be integrated into a decision system, a so-called "Decision Support System", which is intended to facilitate decisions and in this way support the management of stocks.

UFO is a sub-project of AutoMAt, the joint project "Adaptation and further development of innovative, non-invasive monitoring systems and evaluation methods for fisheries research".

target group

Science, politics


We expect high-resolution, continuous and synchronous time series of various properties, behaviors and statistical sizes of the fish stocks recorded by the UFO and their surroundings, which enable us to make an objective and well-founded assessment of the state of the stock and the environment. In addition, concrete statements can be made about the influence of e.g. climate change, fishing activities and other anthropogenic factors such as wind parks or the establishment of protected areas. If a number of such UFOs are set up in key areas, this allows us to make extensive statements about the above-mentioned facts. In this way, we achieve more reliable analysis results that facilitate upcoming decision-making processes and promote sustainable management. Due to its conception, the UFO and the information obtained with its help can be understood as part of a more comprehensive "Decision Support System".

Links and Downloads


RTL: Fascinating images from the underwater world

Thünen contact person

Participating Thünen partners

Involved external Thünen partners


  • Federal Ministry of Food and Agriculture (BMEL)
    (national, public)


7.2013 - 6.2015

Further project data

Project type:
Project funding number: 313-06.01-28-1-28-1-91.007-12
Funding program: Promotion of innovation
Project status: completed

  • UFO flyer This flyer provides a brief summary of the Underwater Fish Observatory.
  • Presentation of the UFO The presentation of the UFO gives a summary and presentation of the project as of October 2014.
  • The press release of the Thünen Institute of February 20, 2014 on the UFO project. This underwater fish observatory is a non-invasive, automatic monitoring system for monitoring fish stocks.