6 GEORGE V SESSIONAL PAPER No. 38a A. 1916 



IX. 



INVESTIGATION OF THE HADDOCK FISHERY, WITH SPECIAL REFER- 

 ENCE TO THE GROWTH AND MATURITY OF THE HADDOCK 

 (MELAN0GRAM3IUS jEGLEFINUS). 



By Dorothy Duff, M.A., McGill University, Montreal. 



The objects of this investigation at the Marine Biological Station, St Andrews, 

 N.B., were as follows : — 



(1) To test the method of determining the age of the haddock by the study of 

 the periodic rings of growth on the scale, and to calculate the rate of growth of this 

 fish from the rate of growth of its scales, as has been done for the herring and cod 

 in the North sea. 



(2) To determine, by measuring representative numbers, the size most abundant 

 in the catches. This to enable us to form some idea of the haddock populrtion and 

 the general condition of the haddock fishery in this region of the North Atlantic. 



(3) To calculate the yearly increase in weight and to find the relation of the 

 weight to the length. 



(4) To determine whether there was any marked difference in size and weight 

 between fish of the same age but of different sex. 



(5) To find the age of maturity for the haddock, that is the age at which they 

 first spawn. 



(6) To gather data leading to the determination of the season of the year when 

 the spawning occurs, and the duration of the spawning period. 



(a) materials obtained and examined. 



We have examined 460 haddock. These were taken at random from twelve 

 different catches, caught on baited trawls during the months of June, July, and part of 

 August, 1914. They are numbered as follows : — 



(1) Numbers 1 to 10— 



Caught in St.- Mary's bay, Nova Scotia. 

 Examined — The Fish Market, St. Andrews. 

 Dat^-June 10, 1914. 



(2) Numbers 11 to 46— - 



Caught — St. Mary's bay, Nova Scotia. 

 Examined — The Fish ]\Iarket, St. Andrews. 

 Date— June 11, 1914. 



(3) Numbers 48 to 57— 



Caught — North channel, between Grand Manan and the Wolves. 

 Examined — Wilson's beach, Campobello island. 

 Date— June 15, 1914. 



(4) Numbers 58 to 65— 



Caught — Off North head. Grand Manan island. 

 Examined — North Head harbour, Grand Manan. 

 Date— June 22, 1914. 



(5) Numbers 66 to OS- 

 Caught — Letite Passage. 



Examined — -The Fish Market, St. Andrews. 

 Date— June 24, 1914. 



