(lines 80-137) was occupied on 7412, 7501, 7507, 7510 and 7511; 

 southerly coverage of this region stopped at Sebastian Vizcaino 

 Bay (line 120) on 7505 and at Pt. Abreojos (line 130) on 7503. 

 The area off southern Baja California (lines 140-157) was not 

 surveyed in 1975. Typically, coverage did not extend beyond 

 station 90 (approximately 160-260 miles offshore) . Cruises 7510 

 and 7511 in our data base are considered as 7510 in the SIO 

 hydrographic data base and are combined in Figure 9. 



Two vessels were employed on these cruises: the David Starr 

 Jordan of NMFS , and the Alexander Agassi z of SIO. The David 

 Starr Jordan was used on seven cruises and the Alexander Agassi z 

 on four (Table 1; Univ. of Calif., SIO, 1984a, b). 



After 1969, CalCOFI surveys were made on a triennial basis. 

 These began in 1972 and continued every 3 years (1975, 1978, 

 1981, 1984) until 1985 when annual surveys were resumed. 



SAMPLING GEAR AND METHODS 



During 1975, a 1-m diameter ring net was used on all 

 cruises; the net was similar to that used on previous surveys 

 except the fabric was 0.505 mm nylon mesh instead of silk bolting 

 cloth (Smith, 1974). The cod end was constructed of 0.333 mm 

 nylon mesh. The frame 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 mouth of each net to measure volume of water filtered 

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



The standard tow in 1975 was an obligue haul to ca . 210 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 



1 

 CalCOFI lines (Figure 11) 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). 



