98 BULLETIN OP THE BUREAU OF FISHERIES 



about 100 mm. long when 1 year old. On the average, then, a yearling is between 

 Z l /2 and 5 inches long. 



Subsequent growth. — The herring has proved a particularly favorable object 

 for age and growth studies based on the structure of the scales, a method of investi- 

 gation that has led to a great advance in the knowledge of the life histories of many 

 of our important food fishes during the past 20 years So easily are herring scales 

 interpreted, thanks to their distinct summer and winter rings, 89 that confidence can 

 be placed in the age-determinations of the many thousands of herrings that have now 

 been examined and in the correlations between age and size resulting therefrom, this 

 phase being better known for the herring than for any other fish. Without enter- 

 ing into this subject, winch would lead us far afield, we may point out that herring 

 not only grow at different rates and that the contrast between the rapid growth of 

 summer and the slow growth of the winter is greater or less in different seas, but 

 that in some localities herring grow rapidly when young and slowly thereafter, 

 while in others they may grow slowly at first but sustain a more even growth to 

 old age, a contrast of this sort obtaining between the herrings of the Magdalen 

 Islands and of the west coast of Newfoundland. 00 



The Dogger Bank herring in the North Sea (to mention a couple of European 

 examples only) approximate 4 inches in length at the end of the first year, S 1 ^ to 9 

 inches at the end of the third, 103^ inches at the end of the sLxth, and llj-^ to 12 

 inches at the end of the ninth year of life, though with considerable variation due, 

 no doubt, to varying food supply and to the general suitability of the conditions 

 under which they live. According to Hjort 91 Norwegian herring spawned in the 

 year 1899 and examined at 10 years of age exhibited the following growth: 3% 

 inches at 1 year, 7}4 inches at 3 years, 11 J-i inches at 6 years, 12 Y^ inches at 9 years, 

 and about 12|^ inches at 10 years. From this it is evident that they did not grow 

 so fast as the North Sea fish at first, but attained the same size at 6 to 9 years of age. 



Huntsman (1919) credits the Bay of Fundy herring with about the same growth — 

 4 inches at the end of its first and 10 inches at the end of the third year — as the 

 Dogger Bank fish, making most of their growth from May to September. Probably 

 the growth period lasts a month later in the southern parts of our Gulf. In Nor- 

 wegian waters it has been foimd that herring grow from April to September only, 

 remaining practically stationary in length from October until March. 92 



Size at maturity. — According to Moore, who examined thousands of fish 

 about Eastport, herring rarely spawn when less than 9^ inches long, usually not 

 until they are 10 to 10J4 inches, with most of the spawners 12 to 13 inches long. 

 This he interpreted to mean that some few spawn when only 2 or 3 years old — 

 most of them, however, first at 4 years or older — to continue spawning annually 



'» See Einar Lei (Age and growth of the herrings in Canadian waters. Canadian Fisheries Expedition, 1914-15 (1919,) pp. 

 75-164) for an account of age-determination by analysis of the scales, as it applies to the herring. 



•o Hjort, Canadian Fisheries Expedition, 1914-15 (1919), pp. xi-xxviii, and Lea, Bid., pp. 75-154. 



•' Conseil Permanent Internationa! pour l'Exploration de ia Mer, P.apports et Proces-Verbaux, Vol. XX, 1914, 228 pp. 

 3 pis. Copenhague. 



u Lea, Einar: A study on the growth of herrings. Conseil Permanent Internatonal pour l'Exploration de la Mer, Publica- 

 tions de Circonstance No. 61 (1911), pp. 35-57. Iljort, Johan: Fluctuations in the great fisheries of northern Europe, viewed in 

 the light of biological research. Conseil Permanent International pour l'Exploration de la Mer, Rapports et Proces-Verbaux, 

 Vol. XX, 1914, 228 pp., 3 pis. Copenhague. 



