areal and seasonal spawning range of the species. On these 

 survey cruises, plankton tows were made to 70 m, a depth which 

 encompassed the vertical distribution of sardine eggs and larvae. 

 Wide-ranging joint biological and oceanographic survey cruises 

 were resumed in 1949 with sardine as the focus; however, an 

 increasing interest in other biological components resulted in 

 the deepening of standard tows to 140 m in 1951. This marked the 

 beginning of truly quantitative ichthyoplankton sampling on 

 CalCOFI surveys. 



Some data resulting from CalCOFI surveys in 1975 have been 

 published. Hydrographic data (Univ. of Calif., SIO, 1984a, b) 

 were presented in standard formats. Distributional maps of 

 larvae of 2 taxa taken on CalCOFI surveys during 1975 are 

 presented in the CalCOFI atlas series: rockfish (Sebastes spp.), 

 Ahlstrom et al., 1978; and northern anchovy (Engraulis mordax) , 

 Hewitt, 1980. 



A computer data base for eggs and larvae of sardine and 

 anchovy, for larvae of Pacific hake (Merluccius productus) , jack 

 mackerel (Trachurus symmetricus) and Pacific mackerel (Scomber 

 japonicus), and for eggs of Pacific saury (Cololabis saira) was 

 established in 1969. The development of a data base for other 

 fish larvae is a complex undertaking because competency of 

 identification has evolved steadily over the past 38 years. We 

 began the task of producing a CalCOFI ichthyoplankton data base 

 and associated data report series in 1983. All available 

 original records for 1975 were subjected to an extensive 

 verification and editing process to produce this report. This 

 and previous (Ambrose et al., 1987a, b,c; 1988a,b; Sandknop et 

 al., 1987a,b; 1988a, b,c; Stevens et al . , 1987a, b,c; 1988a, b; 

 Sumida et al . , 1987a, b; 1988a, b,c) and subsequent reports make 

 the CalCOFI ichthyoplankton and station data available to all 

 investigators and serve as guides to the computer data base. The 

 data base will be modified when additional errors are discovered 

 and when composite taxa from the earlier years are reidentif ied. 

 These reports are the fundamental reference documents against 

 which subsequent changes in the data base can be compared. 



SAMPLING AREA AND PATTERN 



In 197 5, the seven CalCOFI survey cruises occupied stations 

 during portions of all months except April, August, and 

 September. An eighth cruise (7412) , conducted in November and 

 December of 1974, was included in the 1975 data base. A total of 

 1592 stations was included in this data base, with an average of 

 199 stations per cruise (range 50-279) . Coverage of the survey 

 station pattern varied among cruises and the entire survey area 

 was not covered on any single cruise (Figures 1-10, Table 1) . 

 The area off northern California (lines 40-57) was not covered. 

 All major lines were occupied off central California (lines 60- 

 77) on 7412, 7501, 7503, 7507, and 7511; only three lines were 

 occupied in this region on 7505. The area between Pt. 

 Conception, California, and Pt . San Juanico, Baja California 



