April, and October; only two lines were occupied in this region 

 in February, March, and May-July. The area between Pt. 

 Conception, California and Pt. San Juanico, Baja California 

 (lines 80-137) was surveyed on all cruises; only lines 103-121 

 were occupied in August. The area off southern Baja California 

 (lines 140-157) was surveyed in January and April. Coverage 

 extended seaward to station 200 (approximately 600-700 miles 

 offshore) on lines 60-90 (Cruises 6007, 6010) but typically did 

 not extend beyond station 100 (approximately 200-300 miles 

 offshore) . 



Five vessels were employed on these cruises: the Black 

 Douglas and Hugh M. Smith, of NMFS, and the Horizon, Orca , and 

 Spencer F. Baird of SIO. Two to three vessels participated on 

 each cruise with two being the average number. The Black Douglas 

 was used on all cruises. The other four vessels participated on 

 a total of 11 cruises (Univ. of Calif., SIO, 1961, 1962). 



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 4 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. 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 meter was suspended in the 

 center of the net mouth to measure volume of water filtered (see 

 Kramer et al., 1972, for further details). 



The standard tow from 1951 through 1968 was an obligue haul 

 to 140 m depth (to 15 m of the bottom in shallow areas) designed 

 to filter a constant amount of water per depth interval (ca. 

 3m /m of depth) over the vertical range of most ichthyoplankters. 

 Hauls were made at a ship speed of 1.5-2.0 knots and initiated by 

 clamping the net line to the towing cable with the 45 kg terminal 



CalCOFI lines (Figure 12) 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). 



