The impact of fishery with the pelagic and bottom trawls on herring stocks

The analysis of herring Clupea harengus membras samples taken from the diurnal commercial and experimental bottom and pelagic trawl catches at various depths in the open part of the Northeastern Baltic, in the Gulfs of Riga and of Finland in the first half of the 1960s allowed to draw the following conclusions: (1) In all studied areas the share of young herring was higher in the pelagic than in bottom trawl catches; (2) The percentage of young herring was higher in the coastal than in the open sea grounds; (3) In the open sea the trawl fishery was more reasonable than in the gulfs; (4) Owing to the changeover from the bottom trawling to the usage of very large pelagic trawls in 1962-1963, the rationality of exploitation of herring stocks considerably decreased.