TWENTY-EIGHTH BIENNIAL REPORT. 55 



ment with the Bureau of Fisheries. These statistics are, we believe, 

 very accurate, more so than those collected by any other government, 

 and should be of especial worth as giving the individual catch per 

 boat, upon which any real comparison of abundance in successive years 

 must be based. 



This system, being unique, and original, has had its troubles in 

 getting started, there being no precedents to guide in the collection 

 and filing of tlie "pink tickets" as the dui)licate receipts are termed. 

 Ther-e is at present, however, no doubt l)ut that this system is now in 

 full working order. 



As has been found in Europe by bitter experience, these data as to 

 the catch per boat must be interpreted in the light of the nature of 

 the boats and their eciuipineut. Any cluuige in the catching power of 

 a boat necessarily conditions the comparison of its catches from year 

 to year. Therefore, change in gear employed must be carefully watched. 

 With this end in view the Commission has, in accordance with a law 

 providing for it, re(iuir('(l the registration each year of tlie boats and 

 their gear. Necessarily incomplete at the start, each year has seen the 

 list of boats registered more complete, as th(\v have returned to fishing 

 or as new boats have been put into use. This forms a natural eom- 

 l)lcuient to the reeoi'ds of catches landed, and is indispensable. 



From these records of catches and of boats used, there are incidentally 

 compiled the usual form of statistics as to total catch by periods and by 

 localities, as well as by species. The obtaining of such totals is, it is 

 pointed out, entirely incidental and does not serve the primary purpose 

 of the work, the furthering of our knowledge of the abundance of the 

 various species concerned. It does, however, provide a measure of 

 the commercial importance of the industry, and is of interest to the 

 public. Sueli statistics have been issued by the Commission, as noted 

 above, for each (piarter of the year. 



The second type of statistics are in Kuro])e termed "biological sta- 

 tistics." These are taken by means of samples of the catch, and show 

 the varijing (0))ii>()sili(/)i of fhr saitu in recjard to sex, size, etc. They are 

 indispensable in understanding the great natural fluctuations which 

 occur, for those great fluctuations are characterized, and indeed consist 

 of, changes in the internal composition of the catch. Examples of their 

 great usefulness are found in such fisheries as the herring and salmon. 

 These statistics are at present being gathered in two great fisheries, 

 that for the sardine and that for the albacore, by the State Fisheries 

 Laboratory, and the results are being properly organized for use by 

 the assistants engaged. 



It is regrettable that such biological statistics have been collected 

 for but two fisheries, but the time and thought necessary to organize 

 the proper methods have been too much to permit of branching into 

 more fields. Now, however, that the possibilities and necessities of these 

 two cases are well known and can be embodied in a formal routine, it 

 may be possible to enlarge the scope. It is, however, necessary in each 

 case to carefully survey the data obtainable and to carry research far 

 enough to decide upon what the main changes to be expected are. It 

 is also necessary to decide what amount of sampling will correctly 

 define the characteristics of the catch which must be followed during 

 their changes. 



