Information Technology-based System for Supervised Fish-farming via Internet (2001-020)


By taking insight into the procedures being applied in practice in the fresh-water fish-farming industry, it may be noticed that the whole process is usually depending on the on-site personnel skills, experience and subjective decisions. The goal of the project is to build an information technology-based system that would take advantage of using the Internet and an accompanying expert system created by top experts in the fish-farming field and thus enable optimal supervision of the production process governed by objective information collected from the technical equipment installed in the field. Such a concept will elegantly overcome a problem of controlling distant fish farms which are located far from each other. By using new technologies for acquisition of data such as physical and chemical parameters of the fishpond water or parameters of biocenosis, it would be possible to accomplish expert system-based feedback as an on-line service for the field personnel issuing relevant recipes for the type of food and amount of food to be given to the fish population. This would also provide conditions for long-term scientific observation and investigation of the fishpond process behavior in a real-time by watching events as they are registered with the installed measurement equipment. The developed expert system will be completely open to the expert giving him the opportunity to change or add new expert rules in accordance with newly acquired expert knowledge. This will provide possibility of immediate real-time intervention into the system and achievement of further improvements in production.


Ministry of Science and Technology, Republic of Croatia


2001- 2002

Principal investigator(s)

Zdenko Kovacic, Zdravko Petrinec

Project results:

1st phase

  • The concept of the expert system was elaborated and transfer of knowledge about intensive fish farming was initiated
  • The concept of the Internet based access through server-client communication was elaborated
  • Measurement equipment (Thermo Orion 1230 meter) was purchased and tested in laboratory conditions
  • Belje d.d., Mirkovac – Fish farm Podunavlje has offered experimental fishponds for installation of measurement equipment

2nd phase

  • Measurement equipment and computer equipment were installed and tested at the experimental fishpond
  • A program for server-client communication via Internet was implemented (successfully tested on Windows 95/98/ME/NT/2000/XP)
  • A program for statistical analysis of relevant fish farming parameters (water temperature, water pH, dissolved oxygen, fish food)
  • A program interface to the expert system was made to enable recording of on-site feeding actions for the monitoring purpose

3rd phase

  • Installation and functional tests of all equipment were completed (namely, Belje d.d. purchased one extra set of equipment to support the project).
  • Integration and testing of software (together with installed measurement system) was completed. Fish-farm Belje provided access to Internet thus enabling tests of multi client-server communication via Internet (each fish-pond was treated as a separate client)
  • A program tool for connection with a supervisory expert system was finished. A program for continuous insertion of actions taken at the fish-pond was completed for the purpose of “on-line” production observation.
  • After successful tests, the whole system was put in experimental work on two selected fish-ponds of the Fish-farm Podunavlje, Belje d.d., Mirkovec
  • Check-point fish extraction was made for control of fish condition (e.g. weight, growth, diseases). Based on the results obtained the knowledge base was extended.
  • Two papers were written on the subject of the project and were accepted for presentation at the international conferences (see below).

End phase

  • Continuous observation of information technology-based system and analysis of results for comparison with the results obtained without usage of the system
  • Continuous modifications and improvements of software based on experience gained during experimental work of the system
  • Project documentation was written and project web page was created. A photo gallery with a lot of photos showing the equipment and the experimental environment can be seen here.
  • Two papers were presented at the international conferences (see below).

Post project activities

  • A first-year analysis of achieved field results has been made and it has been proven that the expert system ensured smoother growth of fish (see figure below – in the middle) while spending less fish food (see figure below – on the top)
  • It has been found that as the fish-farming process is progressing, the supervised food/weight ratio becomes almost constant compared to the heavily deviating food/weight ratio in the unsupervised case (see figure below – at the bottom).
  • One of the most illustrative parameters of expert system efficacy is the average food/weight coefficient, which is equal to 2,4 in the supervised case, and 3,71 in the unsupervised case. In other words, introduction of the expert system saved 35,3% of food for reaching the same fish weight. Since these experiments are the very first ones, there is still enough room for further improvements.
  • First installation of the expert system on the fish-farm is planned in 2003 at the fish-farm “Riba” d.d., Garesnica, Croatia. There are some other fish-farms interested in installation of the expert system for the purpose of monitoring the fish-pond water quality.

Project references:

PETRINEC K., PETRINEC Z., KOVACIC Z., “An Expert System for Freshwater Fish-Farming Industry”, CD-ROM Proceedings of the IFAC World Congress 2002, 21-26. 07. 2002., Barcelona.

PETRINEC K., PETRINEC Z., KOVACIC Z., “Multivariable Measurements and Observations in the Freshwater Fish-farming Industry: An Internet-based Expert System”, CD-ROM Proceedings of the 12th IMEKO TC 4 International Symposium “Electrical Measurements and Instrumentation, pp. 473-477, 25-27. 09.2002., Zagreb.