Indication of high natural mortality for juvenile herring from acoustic and tagging data.
Original version
This report is not to be quoted without prior consultation with the General Secretary.Abstract
Natural mortality for juvenile herring (Norwegian Spring spawners)
is discussed on the basis of following data:
1. Acoustic estimates of the 1975 and 1976 yearclasses of
herring as 0-group and estimates from tagging data of these
yearclasses as 4 year old fish.
2. Acoustic abundance estimates of the 1978 herring yearclass
in Lavangen fjord, Northern Norway.
These data indicate a high natural mortality for juvenile herring.