DIDSON is an English abbreviation of "Dual-Frequency Identification Sonar".
Another area of activity for the Aquatic Ecology Department is the development, validation and standardization of new methods for surveying fish populations, such as the use of the DIDSON imaging echo sounder on large rivers.
The use of an electric bottom trawl has also been tested and evaluated to detect bottom-oriented fish species in large rivers. Both methods are used to detect fish species and fish biomass, respectively, at water depths that cannot be reached by electrofishing.