r20 FlSn AXD GAME COMMISSION 



Aflor pntoriiiK the ncn, tlioy mny wniidor long dislnnoofi from tlio ni<intli of 

 tlifir native stronin. Klaiiinlh Itivor fish, for <'xnin|ilr, luiKratp southward to 

 Montcn\v Hay, and Sarranicnto Kivcr fish move n considerahlc distance north- 

 ward as well as southward. 



Individual fish at times remain closely associated for n year or more while 

 at sea, |>(>ssilily in the same school. 



Adult fisli return U|)on their n\ii)tial niiirration in the stream from which 

 they enter the ocean, regardless of where the epi^s wore taken. 



When yearlingrs are introduce<l into, and given a siifiicient exposure to the 

 waters of a particular trihutary, they tend on their return migration to seek 

 out and enter that trihuf.iry, while iinder less favornlde conditions they may 

 scatter to a cousidirahle extent. This Ih wh.-it niij^lit he expected in nature, 

 the homing instinct preserving the exact geographic distrihution of the species. 

 while the tendency of individtials to straggle provides a means for the spread 

 of the species as ojiportunity presents. 



Studies relating to the life histoi-y of the silver salmon were* heguii by the 

 introduction of consideralilc ninnhers of marked and unmarked fish in 

 P.oulder Creek and the main channel of San lyorenzo Kiver. Eggs were 

 brought from Reflwood Creek, in the northern part of the state, placed in the 

 hatchery- at IJoulder Creek where, under the care of .Tohn Marshall, foreman 

 of the hatchery, they were kept under observation until the ensuing fish were 

 lil)erated. Silver salmon reared from the eggs of native fish, by C Iv. Frame, 

 foreman of Big Creek hatcherj-, were marked and introduced into Scott and 

 Waddell creeks, and the Pajaro River. 



It is expected that the returning adult fish will furnish us with a verifica- 

 tion of age determinations which have been arrived at from an examination 

 of the scales of adult fish. Also, some notion may be gained as to whether it 

 is fe.asilde to artificially propagate the species in these streams, and what is 

 the best time and place for liberating the young. 



Since the inauguration of an efficient statistical system by the division, the 

 rapid depletion of the salmon fishery has been made apparent. In addition 

 to the ordinary and easily observable phenomena, such as the progressive 

 annual reduction of the catch, the constantly increasing effort expended in 

 making it, the discovery and development of new fishing grounds, the increase 

 of the price paid for the fish, etc., another aspect of depletion, which is less 

 familiar, has appeared. This is an enormous increase in the relative number of 

 two- and three-year fish in the catch, over what may l)e regarded as the 

 normal of pi-eceding years. 



During the season of 1928 it became evident that a considerably larger 

 proportion of small fish were being brought to the markets from sea trolling 

 than ever before. As usual, the fishermen attempted to account for this in 

 various ways, but a small sampling of the Monterey catch seemed to indicate 

 that a large proportion of immature fish was being taken. Of 383 represen- 

 tative samples, 56 per cent were in the second year of growth, and 31 per cent 

 were in the third year. In 1929, a careful survey of the situation was made. 

 At Monterey samples of the catch to the number of 2800 were examined from 

 April 23d to July 29th. Of these, about 17 per cent were in the second year 

 of growth, and G2 per cent in the third year. Approximately SO per cent of 

 the catch consisted of two- and three-year fish. 



Now w'e fortunately have at hand an age determination of large and repre- 

 sentative samples of the Monterey catch for the years 1919, 3920, and 1921, 

 when the relative number of two- and three-year fish did not go over 40 per 

 cent. Unless an unsound inference is being made, it would seem that the 

 supply of old fish is greatly reduced, and that the Monterey Bay catch is 

 considerably reducing the population of young fish which should be left to 

 mature in the near future. 



It is intended now to make an investigation of the seaward migrations of the 

 young fish in Klamath River, to make an examination of the spawning beds 

 in a restricted area of the basin to attempt an estimate of the relative produc- 

 tion of natural propagation in a restricted area, to get some definite idea of 

 damage done by irrigation, etc. As a part of this program, a trap has been 

 installed at the mouth of Shasta River, w'here an observer may make a couut 

 of the .spawning fish which enter the river. No artificially reared fish will 

 be placed in the river, therefore in the course of time a fairly accurate estimate 

 of the results of natural propagation may be made, and some of the difficulties 

 which attend it may be observed. 



