TWENTY-SEVENTH BIENNIAL REPORT. G9 



they are eanght at sea. If this could be doiie it woukl then be a simple 

 matter to determine what streams are furnishing the .salmon which 

 are being caught in any sea trolling district — a very necessary piece of 

 information if we expect to regulate the sea or river fishing properly. It 

 has been concluded that it will take a. vast amount of work anil a good 

 deal of time before we can hope to identify the chinook salmon of any 

 of our streams by the character of that part of their scales which was 

 formed wliile they were fry in their native stream. It may never be 

 possiljle to do this. 



It has been decided that tliis knowledge can best be gained l)y nuirking 

 given numbers of salmon fi\' of the different streams as they are liber- 

 ated from the hatcheries. Several of these marking experiments have 

 been carried out and the results have been so encouraging that a scries 

 of these experiments on a more extensive scale has been planned. It 

 has been found from these experiments that salmon from the Sacra- 

 mento River are caught in the sea by trollers from ]\lonterey Ba\', to 

 Shelter Cove in jMendocino County. Just what projiortion are cauglit in 

 each of these widely separated trolling districts will not be known until 

 more extensive marking experiments are carried out. 



In the light of this slight knowledge gained it seems highly probable 

 that the development of the jMendoeino County salmon trolling, was 

 largely at the expense of the Sacramento River salmon. It is (piite cer- 

 tain that the large catch by trolling off the ]\Iendocino coast came from 

 sources other than our norther^ California streams, and we now can not 

 help suspecting that the fishery was drawing heavily on the Sacramento 

 River salmon supply. This suspicion is strengthened by the fact that 

 the salmon catch otf ]\Iendocino.and in the Sacramento have experienced 

 the same slump during the last three or four years. It is very neceasar.x' 

 that we know how much of the Mendocino catch is from the Sacramento 

 if we are to properly regulate the sea trolling on the Mendocino const. 

 The question is of the utmost practical importance and serves well as an 

 illustration of the practical value of investigation work. 



A second lot of Sacramento River salmon fry were marked and liber 

 ated in the Sacramento two years aw. These fish will be in their fourth 

 year next season and it is expected that captures of these marked fish 

 will throw much light on the movements of the Sacramento salmon in 

 the sea. 



Klamath River salmon fry were marked aiul libei'ateil in the Kiamatli 

 three years ago. Some of these fish were recovered last year, whcii tliry 

 were in their third year, after they entered Kiamatli Kivrr. These 

 salmon were all mature males or "grilse." These marking experiments 

 have been reported upon by Professor J. O. Snyder in past numbers of 

 California Fish and Game. This year the salmon which were 

 marked on the Klamath River are in their fourth year, and individuals 

 were captured by trollers in Monterey Bay, off Point Reyes, Eureka and 

 in the Klamath River. The results of this sea.son's wm-k also will !).• 

 reported in California Fish and Game. 



The first of a new series of marking e.x|)erimenls cm the Klamath 

 River, was started this vear by marking and liberal ing 'io.OIKI fry. Next 

 year this numl)er will i)robably be doubletl half of them to l)e librrated 

 in the ]^tad River, the other "half in the Shasta Kiver, a tributary, in 

 order to get additional light on the parent stream theory. 



