128 EIGHTH PACIFIC SCIENCE CONGRESS 



a vicious circle is established which, unless the fishery is regulated, will 

 continue until the catch becomes so small that it is unprofitable to fish. 



(2) Spawning of sardines occurs in two principal areas, one off 

 Southern and one off central Baja California. Spawning in the former 

 of these areas has been poor in recent years, and it is not definitely 

 known whether sardines spawned off central Baja California contri- 

 bute significantly to the California fishery. 



(3) Spawning is limited to a rather narrow temperature range (of 

 the order of 12.5°C. to 16.5°C.), so that changes in the temperature of 

 the water from year to year may result in poor spawning or a shift of 

 the spawning areas. 



(4) The amount of upwelling of nutrient-rich water from the 

 ocean depths appears to be an important factor in providing food for 

 young and mature sardines, and perhaps affects spawning by its influ- 

 ence on surface temperatures. Along the California coast, upwelling 

 varies from year to year, especially with the velocity of the prevailing 

 northwest winds. These winds also, by their effect on the velocity of 

 the California current and the inshore counter current, may directly 

 affect the movement and the availability of sardines at a given time and 

 place. 



A further general observation may be made. The decline in the 

 sardine fishery has resulted in a diversification of fishing effort, which 

 is, in the long range view, desirable. As shown in Figure 1, there has 

 been a rather rapid increase in the take of other fishes since the sardine 

 fishery began its rapid and catastrophic decline. Obviously not all of 

 this increase has been due to the lack of sardines, but certainly some 

 of it has been due to the fact that sardine fishermen have been forced 

 into other lines of fishing endeavour. 



It is now necessary to conduct studies on other fishes (some of 

 which are referred to as "substitute sardines") to insure that they do 

 not suffer a similar fate to the sardine. The research program, known 

 as the California Cooperative Oceanic Fisheries Investigations, is being 

 expanded to include anchovy, Pacific mackerel and jack mackerel. 

 Other species are also given attention as they come to notice incidental- 

 ly in the course of the work. 



It is believed that the oceanographic information being obtained 

 in these investigations will be of importance in the solution of many 

 other fisheries problems in the future. It is believed also that this type 

 of cooperative undertaking, in which a number of institutions offer 

 their facilities and trained personnel toward the solution of a major 

 fisheries problem, provides an effective method of advancing our knowl- 

 edge of the science of the sea. 



