Predictable swimming behaviour of schools in purse seine capture situations

Abstract Sonar observations of herring, mackerel and sprat schools in purse seine capture situations in the North Sea and off the Norwegian coast revealed rather constant swimming behaviour of individual schools. However, there were large variations between the schools, and also differences between species. The consistency of the swimming behaviour nevertheless enabled development of a simple method to forecast the position of schools. The method may give the opportunity for position prediction on true-motion sonar in real capture situations.