8 U. S. BUREAU OF FISHERIES 



exploited have yielded at their inaxiimun but a third the abundance 

 of fish found oriofinally on the older southern grounds. Some 

 measure of the ett'ect of the closure in relation to this increased in- 

 tensity can be gained by comparing the amount of catch formerly 

 taken' on the grounds along the eastern side of the Gulf of Alaska, 

 with the eli'ect of the fall in abundance from year to year. It is 

 estinnUed that not more than (),000,0()0 or 7,000,000 pounds came 

 from these grounds before the closure, or about 10 or 12 per cent 

 of the total for the coast. The loss of this could not exceed that 

 annually lost through a failing supply, since on the older grounds 

 the fall in abundance was approximately 10 per cent yearly, and on 

 the newer grounds even greater. 



It is evident tliat the close season has met a complexity of condi- 

 tions which destroy its uniformity of operation and that in its appli- 

 cation to one subordinate portion of the fishery it has left abundant 

 opportunity for all supposed benefits to be eliminated. A stream 

 can not be controlled by throwing a dam half across its course. The 

 result is nothing more than an increased rate of flow in the other half. 



The commission has been unable' to devise any general measure 

 for the whole fishery, which would properly meet the needs of the 

 various areas. 



Artificial propagation of the halibut is. for technical and scientific 

 reasons, impracticable. The numbers of young that could be thus 

 ])i-()(luced would be a minute part of those hatched under natural 

 conditions. Their culture would be expensive, and the young fish 

 could not be kept long after''4iatching. Hence, it is evident that the 

 natural supply is overwhelmingly the most important and that it 

 must be cared for. The only adequate manner of meeting the present 

 situation is to i)reserve in each area a sufficient number of young to 

 produce spawning adults and to leave enough of the latter to produce 

 an adequate amount of spawn mider natural conditions. 



It becomes evident, upon the first study of the halibut fishery, that 

 regulations designed to produce and protect such a spawning reserve 

 nnist be adapted to very different conditions in the various areas. 

 The state of depletion varies from area to area, and the need for regu- 

 lation ^•aI•ies accordingly. Certain of the banks have been resorted 

 to for many years, while others are undergoing their first exploita- 

 tion. In accord therewith the yield and abundance of fish varies. 

 Moreover, the initial returns from any l)ank reflect the abundance 

 thereon under natural conditions, and the newer, more westerly 

 banks are mucli less productive naturally than the older southern 

 banks— about a third, in fact. In agreement with the state of de- 

 ]>letion, the percentage of mature fish varies from a very small one 

 on the southern banks to a high one on the western, and there is, 

 therefore, a fishery for spawning-age fish on some banks and a fishery 

 for immature fish on others. The fish on the banks vary not merely 

 in their natural abundance but in tlieir lates of growth and physical 

 characteristics. Thus, the trade terms applied to fish according to 

 size have a verv different meaning and do not indicate their age or 

 their need of protection. The seasons of the fishery vary, also, in 

 accord with the biology of the fish and the geographic location of 

 each bank. In agreement with all this, the same complexity is found 

 reflected in the fleet, the fishery on various banks being carried on by 



