Feeding of mature cod (Gadus morhua) on the spawning grounds in Lofoten

Many authors state that cod (Gadus morhua) do not feed during the spawning period. However, this more or less established fact has rarely been investigated in the field. Here, the content of stomachs from Northeast Arctic cod (NEAC) and Norwegian coastal cod (NCC) sampled from the spawning ground in...

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Bibliographic Details
Main Authors: Kathrine Michalsen, Edda Johannesen, Bjarte Bogstad
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
herring
mature cod
spawning
stomach contents
Arctic
Barents Sea
Fuller
Lofoten
Arctic cod
Gadus morhua
Northeast Arctic cod
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.516.7640
http://icesjms.oxfordjournals.org/content/65/4/571.full.pdf
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Summary:Many authors state that cod (Gadus morhua) do not feed during the spawning period. However, this more or less established fact has rarely been investigated in the field. Here, the content of stomachs from Northeast Arctic cod (NEAC) and Norwegian coastal cod (NCC) sampled from the spawning ground in Lofoten were examined over a 10-year period (1996–2006). The occurrence of food in the stomachs of spawning cod, stomach fullness, diet composition, and variation in these variables between NEAC and NCC, year, and sex were analysed and compared. The analysis shows that cod do feed, even when they are in a spawning state. NCC had a lower pro-portion of empty stomachs and the stomachs were fuller than those from NEAC. Females had a lower proportion of empty stomachs than males and their stomachs were in general fuller. Herring (Clupea harengus) dominated the diet of cod. However, cod consumption of herring on the spawning grounds seems to be a minor source of mortality on herring. Although spawning cod do feed, the proportion of empty stomachs was higher and stomach fullness was lower than in stomachs of NEAC from the Barents Sea.

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