200 



Fishery Bulletin 89(2), 1991 



40 60 



STANDARD LENGTH (mm) 



80 100 120 



AGE (days) 



Figure 6 



Growth rates of juvenile California halibut estimated from the 

 Gompertz parameters for length-at-age, shown with 95% con- 

 fidence intervals. (A) Relationship between growth rate 

 (mm/day) and length (mm); (B) relationship between growth 

 rate (mm/day) and age (days). 



whereas transforming larvae and newly-settled juve- 

 niles were common in 1988. Only the 1988 year-class 

 was used to compare growth and mortality rates for 

 juvenile halibut in bays and on the open coast. Further 

 information on the distribution patterns of juvenile 

 California halibut can be found in Kramer (1990). 



The length distribution of transforming larval and 

 juvenile halibut varied with depth. The smallest length- 

 class of halibut (<7mm SL) was taken at an average 

 depth of 9.6m (SD 3.08, N 54). The mean depth of oc- 

 currence decreased with increasing length up to a mean 

 length of 67.8 mm SL (Fig. 7). At this size, the trend 

 reversed, with mean depth of occurrence increasing 

 with increasing length (Fig. 7). This pattern of length- 

 at-depth indicates that transforming and newly-settled 

 halibut move into shallower water along the open coast 

 and into the bays, and halibut >70mm SL move into 



MEAN BOTTOM DEPTW 

 — 2SE 



40 80 120 160 200 240 



MEAN OF LENGTH CLASS (mm) 



Figure 7 



Mean depth of capture of California halibut by standard length- 

 class (mm). Length-classes (mm) were < 7 (n 54), 8 (52), 9 (47), 

 10 (38), 11-15 (116), 16-20 (198), 21-25 (161), 26-30 (161), 

 31-35 (116), 36-40 (116), 41-45 (138), 46-50 (127), 51-55 (124), 

 56-60 (92), 61-65 (81), 66-70 (92), 71-75 (74), 76-80 (45), 81-85 

 (53), 86-90 (50), 91-95 (42), 96-100 (53), 101-110 (74), 111-120 

 (103), 121-130(101), 131-140(154), 141-150(154), 151-160 

 (109), 161-170(129), 171-180(143), 181-190(121), 191-200 

 (135), 201-210 (128), 211-220 (88), 221-230 (73), 231-240 (60), 

 and 241-250 (47). 



OPEN COAST 

 BAYS 



2SE 



70 90 



AGE (DAYS) 



Figure 8 



Abundance of juvenile California halibut by age-class for open 

 coast and bay habitats in 1988. 



deeper water habitats within the bays (maximum bay 

 depths were <5m) and eventually move out of the bays 

 to the open coast (Fig. 7) (Plummer et al. 1983). 



The age of peak abundance of juvenile halibut in the 

 bays in 1988 was equivalent to the average time re- 

 quired for newly-hatched larvae to move from the 

 continental shelf to the bays. Peak abundance was at 

 about 70 days in both Mission Bay and Agua Hedionda 



