80 FISH AND GAME COMMISSION 



REPORT OF THE CALIFORNIA STATE FISHERIES 



LABORATORY 



"W. L. SCOFIELD, Director 



The research prograiji of the California State Fisheries Labora- 

 tory is primarily a determination of the changes in abundance of our 

 most important species of commercial fishes so that the need for pro- 

 tective legislation can be demonstrated in such fisheries as are shown 

 to be suffering from the strain of over-fishing. Life history and eco- 

 nomic information aid in determining the effectiveness of protective 

 measures recommended or of those already enacted as laws. 



SARDINES 



Our most important fishery is that for sardines as the tonnage 

 delivered is more than twice that of all our other fisheries combined. 

 A major portion of the laboratory program has been a thorough study 

 of the extent of the sardine population, changes in the abundance, 

 variations in the character and composition of the catch, extent and 

 locality of spawning, growth and mortality rates, and the movements 

 of sardines along our coast. Encouraging progress toward definite 

 conclusions has been made during the past two years and reports of 

 the findings are now being prepared. The uniformity of the popula- 

 tion along our coast line, resulting from a comparatively restricted 

 spawning area, is of outstanding importance as indicating that pro- 

 tective legislation should be state-wide in application and that depletion 

 in any one area would lessen the supply in other regions. Our work 

 has shown what may be considered the first danger signs, indicating a 

 heavy drain on the supply, but serious depletion of the supply can not 

 be demonstrated until it occurs. 



MACKEREL 



The mackerel fishery became prominent about four years ago, and 

 life history work on this species was started to learn age, rate of 

 growth, age at sexual maturity, frequency of spawning and such other 

 facts as will serve as a basis for possible future legislation. A study 

 of the fishery has been made to record the gear used, methods of opera- 

 tion, localities fished, and such other information as wall be helpful in 

 an analysis of fluctuations in abundance. Satisfactory progress has 

 been made except for the disappointing lack of material for determin- 

 ing the localities and abundance of spawning. 



CALIFORNIA HALIBUT 



A study of the abundance of the California or southern halibut 

 was completed, showing a steady lessening in the supply. Our recom- 

 mendations as to the need for and kind of protective measures were 

 adopted by the State Legislature. 



