It is clear from these data that: 



1. The total catch per tow (unsegregated year classes) was greatest in depth 

 zone 11 and least in depth zone III whether expressed as numbers or as weight. This 

 situation was found in each survey year . 



2. The young fish (0-4 years) were most abundant in depth zone II and least 

 abundant in zone III whether the catch per tow be expressed in numbers or in pounds . 

 This situation was found in each survey year. 



3 . The older fish, on the other hand, showed the greatest abundance each 

 year in depth zone IV when expressed in numbers or pounds per tow. In practically 

 all cases the zone of least abundance of older fish was depth zone IK. 



4. In all years except 1948 and at all depths, the number per tow of 0-4 -year- 

 old fish was greater than the number per tow of 5-9+ year-old fish with the ratio 

 diminishing with increasing depth. 



5. In all years the weight per tow of 0-4-year-old fish was much greater than 

 the weight per tow of 5-9+-year-old fish in depth zones I and II, practically equal in 

 depth zone III and less in depth zone IV. 



6. In no year was the weight per tow of 5-9+-year-old haddock in depth zone IV 

 greater than the weight per tow of 0-4 -year-old haddock in depth zone II. 



In order to determine at which depth the most valuable quantity of haddock 

 occurred the weight -per-tow data were further classified roughly according to 

 market categories. The following four groups were made: 



1. 0-2-year-oid - representing haddock of unmarketable size. \J 



2. 3-4-year-olds - representing mostly " scrod haddock" which bring the 

 lowest market price. 



3 , 5-9+-year-olds - representing "large haddock" which bring the highest 

 market price. 



4. 3-9+-year-olds - representing all marketable haddock. These fish are 

 sold at a mixed price depending upon the proportions of scrod and large haddock . 



The average weights per tow for each of these categories at each depth are 

 presented in table 8 . 



1/ It must be kept in mind that this division of haddock into marketable and unmarket- 

 able groups according to age is an approximation based on average cori'ditions during 

 the spring and summer seasons . The age of haddock landed varies with the season of 

 the year and with the relative abundance of the various year classes making up the 

 population in the area fished (Schuck and Clark, 1951). An unmarketable haddock is 

 defined as one weighing less than. 1 .5 pounds. In the average year this would include 

 a small proportion of 3 -year -old fish during the spring months and the majority of 

 the 2 -year -old fish during the summer. 



24 



