NOTES Love and U/estphal' Fish populations around oil platforms off Santa Barbara, California 



603 



effort (CPUE), defined as number of fish taken per 

 angler hour, was highest at the 6 Mile Reef, followed 

 by the platforms and the 4 Mile Reef (Fig. 2). 



At the platforms (Table 3) rockfish made up 8 of the 

 10 most-frequently-taken species. While olive rockfish 

 Sebastes serranoides, widow rockfish S. entmelas, chub 

 mackerel Scomber japotiicus comprised 55.9% of the 

 total catch, a number of other species (including canary 

 rockfish, Sebastes pinniger, brown rockfish S. auricu- 

 latus, and bocaccio S. paucispinis were also taken in 

 some numbers. AT the 4 Mule Reef, 8 of the top 10 

 species were rockfish, with blue rockfish Sebastes 

 mystinus, squarespot rockfish S. fiopkinsi, S. serra- 

 noides, and S. paucispinis dominating the catch, mak- 

 ing up 78.8%. Nine of the top 10 species at the 6 Mile 

 Reef were rockfish and S. mystinus, S. entomelas, S. 

 hopkinsi, and S. paudspinis were taken in the largest 

 numbers, forming 82.0% of the total. 



We compared the rank abundances of the top 10 

 species at the three sites with the Kendal tau coeffi- 

 cient test (Sokal and Rohlf 1969). Based on this mea- 



sure, species composition was significantly correlated 

 between natural reefs only, and species arrays from 

 natural reefs were not correlated with that of the plat- 

 form (Table 4). The primary differences between the 

 reefs and platforms were the relative abundances of 

 S. hopkinsi, S. mystinus, starry rockfish S. consteUatus, 

 and flag rockfish S. rubrivinctus at the natural reefs 

 and the scarcity of S. auriculatus and S. pinniger over 

 these reefs. 



With only a few exceptions, all rockfish taken around 

 the platforms were juveniles (Fig. 3). A major excep- 

 tion was S. hopkinsi, a species in which all individuals 

 takn were mature. In addition, a few adult S. auricu- 

 latus and S. mystinus were caught, as well as one ver- 

 million rockfish S. miniatus. At the 4 Mile Reef, a 

 higher percentage of fish were mature. Again, all S. 

 hopkinsi taken were adults, as were most S. auricu- 

 latus and S. miniatus, many S. mystinus and S. rubri- 

 vinctus, and a few S. serranoides. In general, more 

 adult rockfish were taken over the 6 Mile Reef than 

 at the other two stations. All S. hopkinsi were mature, 



Figure 3 (bottom facing page and below) 



Mean size (with 95% confidence interval) of 9 species caught aboard the sportfishmg party vessel Hornet, based on sampling during April 

 1975-April 1978 at three sites off Santa Barbara. Also included are .50% lengths at maturity from data in Wyllie Echeverria (1987), Love 

 et al. (1990), and Love (unpubl. data). 



