40-57) was covered on only two cruises made in May and June. 

 Coverage off central California (lines 60-77) was heavier, with 

 stations occupied on 4 cruises, from April through July. The 

 area between Point Conception and Pt. San Juanico, Baja 

 California (lines 80-137) was occupied monthly from January 

 through July; in August and September only lines 110-137 were 

 occupied, and in October, November, and December, only lines 80 

 through 97. The area off southern Baja California (lines 140- 

 157) was surveyed in January, February, and April. Coverage did 

 not extend seaward of station 90 (approximately 160-250 miles 

 offshore) except on Cruise 5605 when station 100 was occupied on 

 lines 90 through 103. 



Six vessels were employed on 1956 CalCOFI cruises: the 

 Black Douglas of NMFS, and the Spencer F. Baird , Horizon, Orca , 

 Paolina T. f and Stranger of SIO. One to three vessels 

 participated in each cruise. The Black Douglas was used on 6 

 cruises (March; May-September) and the Stranger was used on 5 

 cruises (January-May) . The other vessels were used on 1-4 

 cruises (Ahlstrom, 1958) . 



SAMPLING GEAR AND METHODS 



The standard CalCOFI net used from 1949 to 1969 had a 1-m 

 diameter mouth opening (0.785 m area) and an overall length of 

 about 5 m. The net was constructed of 3 0xxx gauze, a heavy duty 

 grade of silk bolting cloth, with a mesh size of 0.55 mm after 

 shrinkage. The last 40 cm of the cone and the cod end were 

 constructed of 56xxx grit gauze which had a mesh size of 0.25 mm 

 after shrinkage. On five cruises during 1956, Cruises 5607 

 through 5611, the standard net was replaced with one constructed 

 of nylon. Construction of the two nets was similar; however, the 

 nylon nets had mesh sizes of 0.471 mm for the net body and 0.280 

 mm for the end of the cone and cod end. Nylon nets were also 

 used on some cruises from 1957 through 1959, but then their use 

 was discontinued until 1969 (Smith, 1971) . The net ring was 

 fastened to a short 3-lead bridle connected to several meters of 

 line which attached to the towing cable by a clamp. A current 



CalCOFI lines (Figure 14) are arranged perpendicular to the 

 coastline and extend from the Canadian border (line 10) to below 

 Cape San Lucas, Baja California (line 157) . Stations were 

 established on the basis of a perpendicular to line 80 (off Pt. 

 Conception) at a point designated as station 60. Stations were 

 plotted seaward and shoreward from station 60 on each line. 

 Cardinal CalCOFI lines (those ending in "0") are 120 miles apart 

 and usually bracket two ordinal lines (ending in "3" or "7") , so 

 that lines are 40 miles apart over most of the pattern. Cardinal 

 stations are 40 miles apart and typically these are separated by 

 a station number ending in "5" so that stations are 20 miles 

 apart out to station 90 on most lines. Stations are placed at 

 closer intervals near the coast and islands to accommodate these 

 features (see Kramer et al., 1972 for further details). 



