Kendall et al.: Vertical distribution of eggs and larvae of Theragra chalcogramma 



547 







10 



20 



-g 30 



£ 40 



a. 



o 



Q 50 



60 



70 



12 24 36 48 60 72 84 96 



Time (hours since 0000 8 May) 



108 



120 



MLD 



Mean larval depth 



Night 



Mean nauplii depth 

 Tow 6, less deep net 



Figure 4 



Time series of mixed layer depth, mean depth of copepod nauplii, 

 and mean depth of walleye pollock, Theragra chalcogramma, lar- 

 vae starting at 0000 hours, 8 May GMT. Mean depth of larvae 

 excluding the catch in the deepest net of tow 6 also is plotted (see 

 Results: overall depth distribution). Nighttime is shown by stip- 

 pling near the top border. 



5.0"C from about 60 m to the bottom (Fig. 9). There 

 was a gradual thermocline between 10 and 40 m, and 

 most of the larvae were present in or above this fea- 

 ture. Salinity during this series showed a gradual 



increase with depth from about 31.7 ppt at the sur- 

 face to 32.2 ppt at 140 m. Density increased steadily 

 from a a t of 24.85 at the surface to 25.25 at 60 m and 

 25.45 at 140 m (Fig. 9). 



