390 U. S. BUREAU OF FISHERIES 



from the 1933 haddock year class. Therefore, the final 1936 results 

 should be a total Gpor<2:es Bank haddock catch considerably greater, 

 and an average daily trawler catch about the same or a little better 

 than in 1935. 



NoiHi Scotian BanJcs. — The haddock catch on the Nova Scotian 

 banks in 1935 totaled 91,000,000 pounds, an 11-percent increase over 

 1934, resulting primarily from augmented fishing effort. During 

 the first 8 months of the year the average daily catch per trawler 

 was about the same in 1935 as in 1934, indicating that the fishery 

 a]:)parently has not yet made serious inroads into the stock of market- 

 a1)le haddock. However, the catch has been maintained partly as 

 the result of the extension of the fishery to the eastward on Quereau. 



Our knowledge of the haddock popidation off the Nova Scotian 

 coast is less complete than for that on Georges Bank, but it appears 

 that the success of the fishery depends on the same factors, i. e., 

 mortality rate and the contribution to the commercial stock from 

 the younger year classes. If this be true, the 1936 fishery should be 

 somewhat below the 1935 level unless the 1932 year class (which 

 will begin to reach commercial size in the summer of 1936) is rela- 

 tively abundant. 



There have been some indications that insofar as the spring season 

 (that is, the s])awning period) is concerned, a new year class does 

 not exert a maximum effect on the commercial catch during the first 

 year its members reach marketable size. Thus, although the 1929 

 class reached marketable size in the summer and fall of 1933, the 

 catch per day in the following spring (1934) w^as not so great as 

 in the spring of 1935. But during the summer of 1934 the catch was 

 considerably greater than during the summer of the following year. 



Reqniremenfs of the invest i gat ion. — In the above discussion the 

 trend of the fishery has been considered mainly in qualitative terms. 

 The most pressing requirement now is a more complete analysis of 

 material so that the various elements determining the success of 

 the fishery can be studied quantitatively. Only tlien can we accu- 

 rately describe the causes of fluctuations in abundance, or predict 

 the effect of measures designed to improve the catch. Length- 

 frequency and scale data particularly need more thorough study 

 M'hich limitations of time and ])ersonnel so far have made imj^ossible. 

 The haddock fishery is pursued on a large scale throughout the year, 

 and extends over a wide area from Nantucket Shoals to the Grand 

 Bank of Newfoundland. Consequently, an extensive series of data 

 is required to follow the fishery, and there is no slack season in which 

 to bring the analysis up to date. 



Some special problems could not be given sufficient attention dur- 

 ing the past year. An accurate measure of the annual variations 

 in haddock abundance is of fundamental importance to this inves- 

 tigation. In general, these variations are showm by the availability 

 of haddock to the fishermen, which is measured by the average 

 daily catch per trawler. But a change in the efficiency of the 

 fishing boats M'hose catches are analyzed will distort this measure 

 of abundance. Such a change took place during the years 1929-31 

 when the fleet changed over from the ordinary otter trawl to V. D. 

 or semi-V. D. gear. An analysis not yet completed indicates that 

 this increased the efficiency of the fleet by at least 25 to 30 percent. 



