299 
— 
shoals in the spring of the same year would doubtless tend to 
decrease the catches from summer feeding shoals. But the catches 
made from spring spawning shoals in’ 1921 and 1922 give no reason 
for concluding that these shoals have received enormous additions 
from a younger year-class, and they tend to emphasise the conclu- 
sion already expressed that the failure of the fishery was due chiefly 
to the year-class of 1918 being poor. Whilst this is considered the 
chief reason for the failure of the fishery, there is no doubt it was 
accentuated by the number of young fish joining the spring spawn- 
ing shoals of 1921. 
The season of 1921 was very much the same as, but worse 
than, the season of 1920. The catches from spring spawning 
shoals and their age composition, together with the catches from 
summer shoals, indicate that the year-classes which would make 
the summer fisheries of 1920 and 1921 can be considered of little 
value to the fishery. The poor fishery from other shoals, as those 
off Yarmouth in October and November was doubtless due in part 
to the poor year-classes of 1917 and 1918 not yielding sufficient 
immigrants into the shoals, but the age composition of the older 
herrings deserves consideration. Amongst the older fish the 
year-class of 1916, fish with five winter rings in 1921 and which 
gave the summer fishery in 1919, can be said to be a fairly good 
but not a rich year-class. The year-class of 1915 has been poorly 
represented in every sample of herrings examined. Fish with 
seven and eight winter rings in 1921, six and seven winter rings 
in 1920, five and six winter rings in 1919, and belonging to the. 
year-classes 1913 and 1914 have always been present in the samples 
in higher numbers than the 1915 year-class. But these fish must 
naturally be decreasing in numbers and be unable of themselves 
to yield a productive fishery. Before there can be any consider- 
able improvement in our herring fishery a good year-class is a 
necessity, and the first appearance of it will be shown by increased 
catches from summer feeding shoals. 
The possibility of North Sea herrings entering the Baltic 
with increased activity of Atlantic waters is worthy of considera- 
tion, but no data are available in this connexion. Abnormally 
high catches from the Baltic and waters leading to it would have 
to be made to account for the shortage of herrings in our fisheries 
were the failure due to migrations only. 
