A study of the variability in the fish catches taken by successive hauls in the inshore waters off Calicut

Abstract

One of the problems undertaken for investigations at the Calicut Sub-Station of the Central Marine Fisheries Research Station when it was established in May 1948, was a study of the fish populations of the inshore area near Calicut with a view to ascertaining the species of fishes caught from the area, their fluctuations and behaviour. This study necessitated periodical sampling of the populations. The fact that most of the fishes occurring in the inshore waters would be pelagic in nature introducing mobility and mixture was anticipated. The idea of this' study was to find out whether a limited number of sample hauls from such a mobile population would help to know the composition of such a population with a specified degree of accuracy. This needed the study of the variability obtained in the species composition obtained in the catch of successive sample hauls. With this view, four series of sampling trials were conducted over a period of one month and the result of analyses of these trials is given in this communication.