seiitini:' ;i di'siraWlc food in pfopcr 

 form and of (list I'ilxit iiiu' i( so as to 

 eliiuiiiate waste and assure an ade- 

 ((uate daily ration for oaeh lish. A 

 converted potato ricer witli holes of 

 api)ropriate size lias been used suc- 

 ressfully wlien feedini>- small lish in 

 ti'ou<>hs. Food for the tish is i)laced 

 in the ricer and pressure is a])plied 

 by -liaiul to squeeze the food throuah 

 small lioles in the bottom of tlu> 

 ricer. which is moved l)ack and forth 

 in the water, breakino- oti' the 

 "worms"" of food. An extension of 

 this })rincii)le has been developed at 

 t he Leavenworth station of the Fish 

 and Wikllife Service, where a lai-<iv 

 hand-operated })ond ricer is used to 

 feed ponds. At the Coleman station 

 of the Service the same principle is 

 applied, but compressed air is used 

 to drive worms of food through the 

 ricer perforations. The salmon 

 liatcheries now being constructed 

 for the Service include permanent 

 air lines to ponds for pressure feed- 

 ing. These methods have resulted 

 in si.<>nihcant savinj^s in funds and 



lanpow (' 

 a\(' |)i'o( 

 »i'm size. 



d li 



the s; 

 Ithv lis 



Figure 17. — Placing Icod 

 pond with air-pressure 



n a salmiin 

 •icer at the 



Coleman (Calif.) Hatchery of the Fish 

 and ^^■iIdlitV Service. 



THE HATCHERY AND FISHERY MANAGEMENT 



The fingerling salmon prodnced 

 in the modern hatchery are utilized 

 to the best advantage in the mainte- 

 nance and development of popula- 

 tions of fish decimated or threat- 

 ened w^th extinction. A number of 

 hatcheries contribute to sport and 

 commercial fisheries by making pos- 

 sible the capture of substantial 

 numbers of adult salmon that w^ere 

 released as hatchery-reared finger- 

 lings. 



Under natural conditions, that is. 

 in the absence of man-made deter- 



rents to natui'al reproduction, the 

 tremendous salmon populations 

 were able to maintain themselves by 

 entering the many coastal streams 

 to reproduce. The early efforts of 

 Indians in capturing salmon were 

 relatively insignificant, for more- 

 than-adequate numbers of fish usu- 

 ally reached the spawning areas. 

 The fishing methods of the white 

 man were much more intensive and 

 efficient, but even then the tremen- 

 dous catch need not have been par- 

 ticularly harmful to the runs. Sci- 



37 



