66 FISH AND GAME COMMISSION. 



In lieu of fluctuations in catch due to the presence of dominant or 

 suppressed age groups, there have been found great changes due to 

 the sensitiveness of the albaeore to physical conditions. At the present 

 stage of the work, this analysis has been carried only so far as to com- 

 pare the different sections of the individual runs. It will, however, now 

 be attempted to carry the analysis to a comparison of the annual 

 changes with whatever oceanographical or climatological data are 

 available. It is entirely possible that the albaeore runs as a whole vary 

 with, and that their magnitudes are the result of, conditions existing 

 previous to the runs themselves. In such case the prophesying of the 

 commercial catch may be possible. Such a case has been supposed to 

 exist in regard to the mackerel off the British coasts, but the data upon 

 which the reasoning was based seem to us very unsatisfactory ancl as 

 they have never been followed up. we can place no dependence upon 

 the relationship supi:)0sed to exist. It would appear that our knowledge 

 of the albaeore runs is so thorough that we can logically hope for far 

 more satisfactory results than in that case, and it is the present inten- 

 tion to follow the work through. 



It is the hope of the laboratory staff that it may at some time in 

 the future be able to utilize a boat in following up this clue to the 

 behavior of the albaeore. This boat should make a daily traverse of 

 a given region, taking careful scientific records, until a run occurred. 

 Thereby it would be possible to definitely assign the runs of fish to the 

 correct causes. As we have plotted the localities in which runs 

 occur, it seems to us entirely feasible to accomplish this. 



It may be pointed out that, as in the case of the sardine, there has 

 been attained at least partially th»^ first step in tlie understanding of the 

 catch. The varying characteristics of the catch have been accurately 

 recorded, and the actual variation brought to light as far as possible, 

 both as regards the varying classes of fish taken, and as to the varying 

 size of the catches. This, the first step in any scientific analysis of a 

 natural phenomenon, is a secure basis upon which to base decisions. 



However, in considering the detection of overfishing we have found 

 that the presence of this great variability in catch has the same effect — 

 in lesser degree perhaps — that it did upon the detection of overfishing 

 in the case of the sardine, that is, to render it more difficult. A per- 

 sistent decrease in proportion of mature fish and in average catch 

 per boat must be brought to light, and must exceed so clearly the inci- 

 dental variations as to ])e unmistakably significant. Not merely must 

 there be known the proportion oi' each age in the samples obtained by 

 this rigid system, Imt there must be carried forward a comparison of 

 the average boat catcii each year during the runs of the smaller or 

 larger fish. The need for llic "pink ticket" system is obvious and 

 great. It can not be dispensed with lest we lose the most of our signifi- ^ 

 cant evidence. W 



The bearing upon theories of migration of the observed correlation ^ 

 between the albacoi-c runs and the changes in climatological factors, 

 deserves to be sharply emi)hasized. It has been possible to demonstrate 

 this correlation to a sufficient extent so that it seems fairly certain that 

 the minor intraseasonal so-called "runs" are not due to incoming 

 schools but to schools whicli are already present. None of the evidence 

 of migration has been found to bear critical examination. We must 



