Method and device for determining the migration times of fish

摘要

A number of the fish are retained in a defined volume of water where they can behave naturally, but cannot escape. The position of each fish is repeatedly detected. The activity pattern of fish movements is calculated and continuously compared with a stored neutral pattern that was determined during a non-migratory phase of the fish. In the event of a sufficiently large difference between the actual activity pattern and the neutral pattern, a signal is output indicating the migration time. Radio transmitters and antennae may be used for detecting the fish positions. An Independent claim is included for a method of determining migration time. An apparatus is also claimed.