12 U. S. BUREAU OF FISHERIES 



sible that the maximiiin rate of replacement was reached long before 

 the thinning out had proceeded as far as it has. In that case a larger 

 population of halibut than now exists on the banks would give a 

 proportionately larger total replacement, and a greater amount 

 would be available for the fishery without harm to the species. 

 Therefore, once the halibut fisher}'^ is brought to a stable condition 

 the question Avill undoubtedly arise as to whether a further step to 

 increase the " breeding stock " may not be advisable. This distinct 

 possibility of increase in total yield would necessitate a temporarily 

 greater restriction than that which is here proposed. 



The determination of the amount of the reduction in the total catch 

 from any area must, then, be guided by a study of the amount of 

 fishing in relation to the returns. In making this determination, the 

 discretion of the regulatory powers must be relied upon in drawing 

 conclusions from the statistics obtainable. The latter should, how- 

 ever, be as accurate and comprehensive as is possible. The informa- 

 tion now in the hands of the commission is very extensive for 

 recent years but less so for the earlier years. It must serve as a basis 

 for the initial reduction. For the period 1906 to 192G the rate of 

 fall in abundance has been 10 per cent a year, with minor fluctua- 

 tions of one to five years in duration, when there may or may not 

 have been a continuous fall. Further reductions should be based on 

 accurate, comprehensive data as to men, boats, and gear used and the 

 returns therefrom, so that the condition of the fishery may be meas- 

 ured in as many ways and as correctly as possible. Upon this infor- 

 mation the rate of reduction in total catch should be revised at as 

 frequent intervals as possible. 



Tlie frequent revision of this rate of reduction is necessary for 

 several reasons. In case the reduction reflects the changes in the 

 abundance of fish, as shpwn by the catch of a given amount of gear, 

 unnecessary increases and- decreases in fishing operations would be 

 avoided. Furthermore, in case the rate of decline in abundance 

 slackens, the reduction in the catch should be less, so tliat when the 

 fishery becomes stable in yield, reduction will cease at once. 



From present statistics, the initial total catch from which the 

 reduction should be made can only be estimated for the several 

 regions. The information at hand is designed to be representative 

 only, and not comprehensive. It was obtained through voluntary 

 returns and may not give results comparable with those from a more 

 complete legally enforceable system. The commission regards it as 

 necessary that the installation of a complete system of records be 

 made at once, so that the initial amount from which reduction is 

 mafle shall have been obtained by the same system and under the 

 same conditions as those subsequently determined as limits. For 

 that reason no reduction should be made until complete returns are 

 at hand for a full year. 



As has already been said, the reduction made in the total catch 

 should vary with the needs of the various areas. This implies the 

 formation of such areas for administrative purposes. In view of the 

 fact that such control, if adopted, would be applied for the first time 

 in the history of deep-sea fisheries, it is the commission's opinion tliat 

 they should be large enough to render enforcement easily effective, 

 and that they should correspond to a natural division of the fleet. 



