DATA ON THE FOOD OF THE ATLANTIC HERRING 



V. A. Rudakova 



INTRODUCTION 



Food is the most important factor influencing herring distribution during the spring and 

 summer. Our present work is a study of the food of the Atlantic -Scandinavian herring ( Clupea 

 harengus harengus L.) and the interaction between its food and the individual stages in its physio- 

 logical condition. 



Regular observations of the nutritional conditions with due allowance for the hydrological 

 regime , distribution of food organisms and composition, as well as the age structure of the stock 

 will help towards a knowledge of herring migrations and will undoubtedly be of practical assistance 

 to the herring fleet. 



So far, the data obtained enable us to give only an outline of the annual feeding cycle of the 

 herring and to discover some general rules governing the influence of food on the subsequent stages 

 of biological development . 



The data given in the literature on the feeding habits of the Atlantic -Scandinavian herring 

 are limited to the composition of the herring's food during the summer. 



In foreign countries, the Atlantic-Scandinavian herring has until very recently been the ob- 

 ject of coast fishing. This fact has resulted in an almost total absence of research into the feeding 

 habits of the herring in the open sea. Our data, which were collected in the North Atlantic seas 

 during the period 1951 55 are the first collation of results of studies of the contents of herring 

 stomachs . 



A study of the food of Barents Sea herrings belonging to younger age groups has been carried 

 out by G. V. Boldovskiy (3, 4), B. P. Manteyfel' (7) and others. 



G. V. Boldovskiy considers that the seasonal fluctuations in the feeding rate of the herring 

 are due to qualitative variations in the composition of the food. In the case of Barents Sea herring, 

 the feeding rate was at its maximum in June and July, i.e. the season when the herring feeds on 

 "red feed" ( Calanus finmarchicus ). The autumn decrease in feeding continues from August to Oct- 

 ober, the principal food at this season being Euphausiacea. During winter, the feeding rate de- 

 clines, although feeding does not cease altogether. Boldovskiy also jwints out that the feeding rate 

 of the herring is in inverse ratio to its fatness. 



Pchelkina (10), in her work in the Barents Sea, draws attention to the relationship between 

 the zooplankton and the herring - a connection which varies according to the season of the year. 

 The positive correlation between the distribution of the herring and that of the copepod Calanus fin- 

 marchicus is particularly noticeable during the development period of the latter (in June). Large 

 schools of intensively feeding herrings have been encountered in the zone of concentration of Cala- 

 nus finmarchicus . During the spring months, no relation between the distribution of the herring 

 and that of the plankton was observed. 



Ambroz (1) notes that in the case of the Pacific herring there is no starvation period in the 



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