162 FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



and again during August 3 to 12, and, in the meantime, No. S3 was making net hauls 

 in the southern half of the Gulf during June, July, and August, the two boats together 

 making about 50 net hauls in the productive southern half of the Gidf during the 

 mackerel spawning season (Dannevig, 1919, charts and tables). 



While it cannot be said whether more intensive work over a more uniform pattern 

 of stations would have revealed substantially a greater or less number of eggs than 

 was taken by the Canadian Fisheries Expedition, the fact remains that only one of 

 their hauls yielded more than a thousand eggs and only a few, more than a hundred. 

 Experience in the area between Cape Cod and Cape Hatteras indicates that a similar 

 coverage, with similar techniques, would have resulted in many more hauls containing 

 thousands of eggs, and the conclusion appears inescapable that eggs were much less 

 abundant in the Gulf of St. Lawrence in 1915 than in the area between Cape Cod and 

 Cape Hatteras during 1927 to 1932. 



It is difficult to determine how much the decade of difference in the time that the 

 Gulf of St. Lawrence and the area between Cape Cod and Cape Hatteras were investi- 

 gated affects the comparability of the data on egg numbers, but at least two obvious 

 features may be considered — annual fluctuations and long-term trends in volume of 

 spawning. In the area between Cape Cod and Cape Hatteras the numbers of eggs 

 were consistently high during the years 1927 and 1932. Though the methods of tow- 

 ing varied too much and the coverage in some years was too deficient to permit mathe- 

 matical demonstration of this, in every year the eggs were sufficiently abundant to be 

 taken by the several thousand per surface tow at favorable times and in favorable 

 places; and it may be concluded that annual fluctuations were not sufficient to alter 

 the general magnitude of egg production. It appears also that the numbers of spawn- 

 era, judging from catch statistics, did not fluctuate by orders of magnitude during 

 this period. Thus, experience suggests that the egg yield does not fluctuate markedly 

 as long as the number of spawners does not. 



Referring now to the catch statistics in the Canadian and the United States 

 fisheries (Sette and Needier, 1934, p. 43) it appears that the trend in Canada was nearly 

 horizontal between 1915 and the late 1920's, but that in the United States the general 

 level was about three times as high in 1929 as in 1915. If it may be assumed that the 

 spawners are, in general, proportional to the catch and that the numbers of eggs are 

 proportional to the number of spawners, both of which are admittedly questionable 

 premises, then it could be argued that the 1915 Canadian data on eggs would roughly 

 hold for recent times and the comparison justified as indicating relative amounts of 

 spawning in the two areas in recent times. On the other hand, comparison as of 1915 

 might be expected to reduce by two-thirds the numbers of eggs in the Cape Cod to 

 Cape Hatteras area, and thus indicate relatively greater importance for the Gulf of 

 St. Lawrence. Even so, the change would not be one of order of magnitude. 



All available information considered, it appears most likely that the spawning in 

 the area between Cape Cod and Cape Hatteras is distinctly more important than hi 

 the Gulf of St. Lawrence, and though it is possible that the difference is one of an 

 order of magnitude, with eggs so concentrated in the Cape Cod to Cape Hatteras 

 legion as to be available in the thousands per tow, and so scarce in the Gulf of St. 

 Lawrence as to be available in the hundreds per tow, it is also possible that the true 

 divergence is less marked and that the numbers are really in the upper and lower 

 levels of the same order of magnitude. The diagrammatic representation of relative 

 egg numbers in the various regions given in figure 3 shoidd be considered with this 

 reservation. Although the collection of more adequate data on the subject is greatly 



