PROGRESS IN BIOLOGICAL INQUIRIES, 1934 341 



haddock to (his stock. To estimate the size of this contribution a 

 year or luoro in advance, it is necessary that it bo possible to evabiate 

 the abundance of liaddock before they reach connnercial size. For 

 this work it is essential that a vessel be available for the collection of 

 extensive samples of younf]j haddock with small-meshed otter trawls. 



An example of the limited reliability of forecasts based on present 

 observations can be found in the 1933 annual report on haddock. 

 That report discusses the probable course of the fishery on Georges 

 Bank during 1934 and 1935. At that time it appeared that the catch 

 per trawler day in 1934 would be somewhat less than in 1933. Actu- 

 all}' the catch was somewhat better, due to the great reduction in fish- 

 ing effort and to unexpectedly large contributions from the 1931 

 class, which it had been impossible to evaluate accurately until 1934, 

 when it appeared in the commercial catch. Similarly, in the 1933 

 report the probability was expressed that the 1932 class was a failure 

 and that consequently the fishery would continue to decline in 1935. 

 Kesults of the fishery in the last part of 1934, however, indicate that 

 the 1932 class is much larger than was supposed and may furnish a 

 considerable contribution to the commercial stock. The abundance 

 of this class cannot be determined from commercial-catch data until 

 late in 1935. Consequently, at the present time it is impossible to 

 make anj^ predictions as to the 1935 fishery on Georges Bank except 

 the general one that with fishing effort distributed as in 1934, the 

 catch per day in 1935 probably will be considerably better than in 

 the previous year. 



Nava Scot i an hanks. — In 1934 nearly 90,000,000 pounds of haddock 

 were landed from this area. This was about two-thirds of the entire 

 United States catch and approximately twice as much as was ever 

 before landed from these banks by the United States fleet. The 

 actual level of abundance of commercial haddock, as shown by catch 

 per day during the first 8 months of 1934, was about 10 percent 

 higher than during the corresponding part of 1933. The increase 

 was due to the 1929 class which came into the commercial fishery in 

 the summer of 1933. (This same class on Georges Bank came into 

 that fishery in the fall of 1931 owing to the faster growth rate in 

 that area.) 



The development of the fishery during the first 8 months of 1934 

 was much as anticipated in the 1933 annual report. At that time 

 it was predicted that there would be an improvement in 1934 over 

 1933 in the catch per day during the spring and summer and a de- 

 cline in the fall and winter. The spring and summer fishery has 

 followed this trend although for various reasons the increase was 

 not as great as was anticipated. 



The fishery on the Nova Scotian banks should continue good in 

 1935 but somewhat below the 1934 level. However, this estimate 

 can be no more than an approximation because of certain unevalu- 

 ated factors. The 1931 year class will reach commercial size during 

 the summer and fall of 1935 but it does not appear to be sufficiently 

 abundant in this area to compensate fully for the decline in the 

 present marketable stock owing to catch and natural mortality. 

 Unfortunately, no reliable measure of the abundance of the 1931 

 year class is available due to the scarcity of information concerning 

 the submarketable sizes. Our only basis for an estimate is a series 



