LOVE ET AL.: DISTRIBUTIONAL PA'ITKRNS OF KISHKS 



Table 1.— Partial list of fishes taken aboard commer- 

 cial passenger fishing vessels during sampling from 

 April 1975 to December 1978 around the northern 

 Channel Islands. Only those species where 10 or more 

 individuals were tal<en are listed. 



As virtually all fishing effort in waters deeper than 

 72 m was carried out in the eastern part of the chain, 

 no analyses were conducted of catches in these 

 depths. Most species' abundance trends occurred in 

 the shallowest (0-36 m) depth interval. No samples in 

 0-36 m were taken in blocks 688, 689, and 709, and 

 none in 37-72 m in blocks 690, 709, 720, 411, and 

 712. 



Fourteen species (Table 2) decreased in abundance 

 along the island chain in 0-36 m (Table 3, Kolmo- 



gorov-Smirnov goodness of fit test). Of these, eight 

 species {Ophiodon elongatics; Paralabrax clathratus; 

 Pacific bonito, Sarda chiliensis; Scomber japonicus; 

 China rockfish, Sebastes nebulosus; yellowtail, 

 Seriola lalandei; Pacific barracuda, Sphyraenxi 

 argentea; jack mackerel, Trachurus symmetricus) 

 were absent around either the extreme eastern or 

 western end of the chain. The abundance of seven 

 species {Paralabrax: clathratus, Sarda chiliensis, 

 Scomber japonicus, Scorpa£na. guttata, Seriola 

 lalandei, Sphyraena argentea, Trachurus symmetri- 

 cus) decreased toward the west and seven {Ophiodon 

 elongatus; copper rockfish, Sebastes caurinus; S. 

 miniatus; S. mystinus; S. nebulosus; S. paucispinis; 

 S. serranoides) decreased toward the east. 



The catch per unit effort (CPUE) of six species 

 {Ophiodon elongatus, Sebastes caurinus, S. miniatus, 

 S. mystinus, S. paucispinis, S. serranoides) increas- 

 ed in the next (37-72 m) depth interval (Table 4). The 

 largest increases occurred around Anacapa (blocks 

 684, 707) and the eastern end of Santa Cruz (685, 

 708). In most instances, catches increased by a factor 

 of 10 or more in these four blocks. The CPUE of 

 three species {Sebastes miniatus, S. serranoides, and 

 S. paucispinis) were over 100 x as great in several 

 blocks. 



There was a cline in the mean lengths of four 

 species {Sebastes caurinus, S. mystinus, S. paucispi- 

 nis, S. serranoides) in the shallowest depth interval 

 along the island chain (Fig. 2). All four species were 

 largest in the shallow waters of the more westerly 

 islands, particularly San Miguel. 



We compared mean lengths of each species be- 

 tween blocks within the 0-36 m and 37-75 m depth 

 intervals using the Student-Newman-Keuls multiple 

 range test (Sokal and Rohlf 1969). In the shallowest 

 interval, Sebastes caurinus, S. mystinus, and S. ser- 

 ranoides were largest off San Miguel, while S. 

 paucispinis lengths were greatest at San Miguel and 

 Santa Rosa. Two groupings, San Miguel-Santa Rosa 

 and Santa Cruz-Anacapa, were evident in three 

 species {Sebastes mystinus, S. paucispinis, S. ser- 

 ranoides) as mean lengths of these tended to form 

 somewhat discrete units. For Sebastes caurinus, San 

 Miguel, Santa Rosa, and the west end of Santa Cruz 

 formed one entity - eastern Santa Cruz and Anacapa 

 another. 



For these four species, mean lengths were, in most 

 instances, greater in each block in deeper (37-75 m) 

 waters. Though some of the groupings of 0-36 m ex- 

 isted, there was some breakdown of this pattern. In 

 Sebastes paucispinis, for instance, the mean lengths 

 of Santa Rosa (block 688) and Anacapa (707) fish 

 were similar, though they were different in 0-36 m. 



245 



