FISIIKRV INDl'KTRIES. 31 



to the spines or carpal bonos on which the rays rest — will bo perma- 

 nent, and the tin will not grow again. 



wSome experiments were made at tlie Yes Bay hatchery this season 

 to arrive at a definite method of marking fnigerlings and it is believed 

 tliat the results point to a i)racticable S3^stem, but further tests are 

 required to perfect it. Observations of the "marked" fish noted 

 above demonstrate the necessity of a marking which can not be 

 duplicated by unauthorized experimenters and which will authenti- 

 cate the returned fish beyond all question. 



HATCHERIES. 



EXTENT OF OPERATIONS. 



During the year 1912 seven salmon hatcheries operated in Alaska 

 as heretofore. The Karluk plant is the only hatchery at which the 

 take of eggs w^as up to the limit of capacity. The takes, however, 

 are not always true indications of the runs at the various streams. 

 At the Karluk station the parent fish are seined from the lagoon 

 which receives Karluk River. These fish are of the number which 

 have escaped the cannery seines at the spit and are on their way to 

 their spawning grounds about Karluk Lake. This escape is always 

 greatly in excess of the needs at the hatchery. Such a number of 

 them as it is believed will be required to furnish suflicient spawn to 

 fill the hatchery are intercepted and held in corrals till ripe. The 

 number of eggs taken at this place therefore depends neither on the 

 total run of fish nor on the escape, but upon the judgment of the 

 hatchery superintendent, qualified by the loss of fish in the corrals. 



At the Yes Lake station also the number of eggs taken is only 

 indirectly related to the size of the run. Commercial fishing Is car- 

 ried on in the bay or immediately adjacent waters under the super- 

 vision of the hatchery superintendent. When in his judgment the 

 run exceeds the number that are required for hatchery purposes, 

 then commercial fishing is allowed; if the run seems insufficient^ 

 then commercial fishing is interdicted until the superintendent be- 

 lieves enough fish have entered the lake to supply the quantity of 

 spawn needed to fill the hatchery. 



As the number of fish entering the lake can be estimated only by 

 the apparent abundance in the bay and stream, it will sometimes 

 happen, as in the past season, that not enough fish reach the lake to 

 fill the hatchery; but such a shortage does not necessarily imply a 

 small run. 



On the other hand, the hatcheries at Afognak, Loring (Fortmann) 



Klawak, Hetta, and, usually, Quadra have of late yeai-s made use 



of all the fish available for their purposes and yet failed to fill their 



troughs. From this statement must be excepted the single season 



6711°— 13 3 



