114 



Fishery Bulletin 98(1) 



far more abundant around southern California plat- 

 forms. This conclusion comes from observations we 

 made in the mid-1970s, a period of relatively strong 

 juvenile rockfish recruitment off California (Love and 

 Westphal, 1990). During that period, we observed a 

 significant recreational fishery directed at juvenile 

 widow rockfish and bocaccio (and to a certain extent 

 olive and blue rockfishes) at platform Holly, as well 

 as at a number of other Santa Barbara Channel plat- 

 forms. We estimate that tens of thousands of these 

 YOY and 1- and 2-yr-old fishes were caught over the 

 course of about three years. 



The absence or relative rarity of such common 

 nearshore species as kelp bass (Paralabrax clath- 

 ratus), opaleye iGirella nigricans), black seaperch 

 (Embiotoca jacksoni), and white seaperch (Phaner- 



odon furcatus) from the upper waters was partic- 

 ularly striking. This is in contrast to the inshore 

 platforms and reefs of this area that harbor many 

 of these species (Carlisle et al., 1964; Ebeling et al., 

 1980; Schroederf ). A most important cause for the 

 absence of nearshore species is the isolation of these 

 offshore structures; relatively deep water separates 

 them from the mainland. This distance may effec- 

 tively cut these species off from source populations 

 of many shallow-water species. Thus, it may be dif- 

 ficult for the young of many species to either reach 

 these platforms or become established there. Sea- 

 perches are viviparous and produce fully developed 



^ Schroeder, D. 1997. Marine Science Institute, University of 

 California, Santa Barbara, CA 93106. Personal commun. 



13 



— t— 

 23 



l.OOfri 



750- 



I— 

 u 



XI 



E 500- 



3 



z 



250- 

 0- 



Widow rockfish 



I 



-M-P- 



1 — I — I — i— 



13 18 23 28 33 38 43 48 



150 



100 



50 



Bocaccio 



I 



-I— t- 



X^ 



-r—r 



3 8 13 18 23 28 33 38 43 48 53 58 



Copper rockfish 



13 18 23 28 33 38 



300- 

 250- 

 200- 

 150- 

 100- 

 50- 

 



Greenspotted rockfish 



I 



MYn. 



13 18 23 28 33 38 



Flag rockfish 



13 18 23 28 33 38 

 Midpoint length (cm) 



80 



Lingcod 



 Bottom 

 n Midwater 



0-^ 



f tT I f TT 



8 1318232833384348535863687378 



150- 



100- 



Vermilion rockfish 



50- 



8 13 18 23 28 33 38 43 48 53 58 



Halfbanded rockfish 



1 1 — ^- 



13 18 23 28 33 



Figure 8 



Length-frequency distributions of nine common species on midwater and bottom tran.sects on all platforms combined. Midpoint 

 length is the midpoint of .S-cm length bins. 



