Love et al Life history aspects of Paralabrax clathratus and P nebuhfer 



473 



Love et al. 2 ). Measured by catch per unit of effort, 

 both species rank annually among the top three spe- 

 cies in the commercial passenger fishing vessel catch 

 (Love et al. 2 ). 



The life histories of these two species are poorly 

 understood. While there is some information on habi- 

 tat preferences, food habits, and reproduction, sum- 

 marized in Read (1992) and Ono ( 1992), data on age 

 and growth as well as size and age at first maturity 

 and recruitment are limited. We describe the age and 

 growth patterns and size and age at first maturity 

 relationships for kelp bass and barred sand bass in 

 the southern California Bight. In addition, we pro- 

 vide information on recruitment of kelp bass to a 

 nearshore southern California reef. 



Methods 



Recruitment and annual abundance 



Since 1974, we have used 5-min isobathic diver 

 transects at 3-m depth intervals between 1.5 and 15 

 m at 8 stations along the breakwater in King Har- 

 bor, Redondo Beach, California (Fig. 1) to estimate 



2 Love, M. S., A. Brooks, and J. R. R. Ally. 1996. An analysis 

 of the commercial passenger fishing vessel fisheries for kelp 

 and barred sand basses (Paralabrax clathratus and/ 3 nebuhfer) 

 in the southern California Bight. In review. 



King Harbor 



Figure 1 



Location of underwater transect sites (marked with a 

 "T"), King Harbor, Redondo Beach, California. 



fish abundance by life history stage. During these 

 transects, divers swam along the vertical face and 

 counted all fishes in a 3-m deep band (1.5 m above 

 and below the diver). Outer harbor transects were 

 254 m in length, inner ones were 208 m long. 

 Transects were swum monthly in 1974 and 1975 and 

 quarterly after 1976. For the years after 1975, this 

 survey yielded 96 transects per year (8 stations and 

 3 depths surveyed quarterly). 



We obtained data on month of recruitment for kelp 

 bass from 1986 to 1992 by conducting a monthly sur- 

 vey along the inner wall of the Redondo Beach break- 

 water and along a rock groin within the inner har- 

 bor. Three divers (at depths of 0-3, 4-6, and 7-10 m) 

 swam parallel transects along approximately 500 m 

 of rock and closely inspected bottom cover, crevices, 

 and algae for newly settled fishes (Pondella and 

 Stephens, 1994). The survey along the inner rock 

 groin was similar, except that only two divers swam 

 transects (one shallow, one deep), because of the shal- 

 lower (1-4 m) location. Fishes ranging from 1.5 to 

 2.0 cm were considered newly recruited. Juveniles 

 were considered to be those fish from 2.1 to 10.0 cm, 

 and subadults ranged from 10.1 to 15.0 cm. Barred 

 sand bass do not recruit from the plankton to the 

 rocky substrate of King Harbor. 3 



Age and growth 



Between 1978 and 1992, we collected kelp and sand 

 bass throughout southern California waters by us- 

 ing hook and line as well as pole spear. These samples 

 were supplemented by fish from commercial passen- 

 ger fishing vessel (CPFV) catches, from kills at 

 coastal power plant intakes (water heat treatments), 

 from experimental gill-net studies, and from Cali- 

 fornia Department of Fish and Game wardens. Data 

 collected from all fishes included total length, sex, 

 capture location, and collection date. We ascertained 

 whether the fish were mature or not by an inspec- 

 tion of their gonads during spawning season. We also 

 collected otoliths from each fish. In cases where stan- 

 dard lengths were recorded, we converted these to 

 total lengths by using length conversions (Table 1). 

 Otoliths were embedded in plastic and sectioned 

 prior to being read. We made an embedding mold 

 from 3/4-inch pvc pipe with stoppered ends, cut in 

 half longitudinally. A thin layer of resin ( 1/4 inch 

 thick) was poured into the mold and allowed to 

 harden. The otoliths were then placed into the mold 

 with a label containing an identification code and 



3 Pondella, D. 1995. Department of Biology, Occidental Col- 

 lege, 1600 Campus Rd., Los Angeles, CA 90041. Personal 

 commun. 



