TWRNTY-SFA'KX'I'II I'.II'.N Nl Al , KI'.I'OKT. 77 



()!• sciifcc, ;is we now will l)r ;il»lr lo i|i>, will hr (if liciiclil 1o llic i-;itiiii'l"s. 

 Jt will ;ils(> lie ol" ticiiclil lo tln'iii lo kimw I'liit ;i si-iiri'ily is (Jiic lo 

 niitui'iil cjiiiscs ;iii(l iiol to ovcflisliiiiu. 



'I'lic siii'diiic, il lijis hccn roiiiul, urows riitlur' ijipiilly in Ji-niilli ;it 

 fii'st. At the end of the (irsi year's jiTowtli they Jivcraji'c not (|iiitr four 

 inc'lu'S in Icniilli; ;it the cml of 1 wo ycjii's iiliont six jiikI llircc (|n}irt('r 

 inches; ;il llic end of ihi'cc ycjirs Jibout ci^jht jiikI onc-tiniirtiT inciics; 

 while at Ihe eiul ol' lonr yeaivs Ihey reaeh a Icjiuth of aliont^ nine 

 inches. From Ihe ^fowth ciirxt' estalilished from these k-nown fiu'iires 

 the ao-e of tlie larjjer sizes can he estimated a|i|iioximateI\'. The huyest 

 sizes may he ten or twelve years old. The ui'owth enrve of our sardine 

 is similar to tliat of the European sardine. Our sardine is also similar 

 in its spawning' habits, in that the spaw'nin'4' season extends over 

 several months of the spring' and suinmei- and in that the spawning 

 sardines leave the coast and probably spaw'u well off shore. 



The sardine work had not progressed very far before it became 

 evident that there were several factors which ijiflnence the size of the 

 sardines taken by the fishermen. A great deal of work has been done in 

 determining the effect of these factors and this woi-k will be treated 

 fully in the report of the work now^ about com])leled. 



The influence of these other factors on the size of the fish in the 

 cateli would probably not have been detected had samples of the 

 ( .itcli been taken only a few times a month as has been done in Europe 

 in similar work. In fact entirely erroneous conclusions could have 

 been arrived at. This led to an investigation by ^Ir. Sette to determine 

 the error involved in different methods of sampling. This work is 

 a contribution of considerable value to the methods employed in fisheries 

 investigations and besides casting doubt on some of the conclusions 

 arrived at through insufficient sampling in Europe, it shows how large 

 the samples should be and how frequently they should be taken. 



Daily samples of the catch have been taken over a period of two 

 years in order to work out and determine the seasonal fluctuations in 

 size and also the fluctuations in size within the lunar periods and also 

 to explain the causes of these fluctuations. That these factors are 

 important is shown by the fact that the rate of growth in this instance, 

 and the dominance of year classes conld not have been determined 

 without knowledge of the fluctuations in the size of the fish taken by 

 fishermen during different phases of the moon. After this season 

 samples need be taken only at intervals of twice a week at IMonterey 

 as was done the present season at San Pedro, and on that account the 

 work will be simplified and reduced to a large extent and it will be 

 necessary only to follow the abundance of the year classes as is now 

 being done in the case of the albacore. We will then be able with 

 our present force to take up the investigation of other important 

 fisheries which are in danger of depletion, such as the barracuda and 

 white sea ba.ss. 



PURSE SEINE INVESTIGATION. 



We mentioned in our last report how purse seine fishing had been 

 introduced into Southern California mainly for the purpose of catch- 

 ing blue-fin tuna. It was complained by other fishermen that these 

 boats in using their nets for other kinds of fish caused great wa.ste, 



