FISHERY BULLETIN: VOL. 83, NO. 2 



during the day (Hobson and Chess 1976; Allen and 

 DeMartini 1983). Queenfish are dispersed 

 throughout the water column and also occur 

 farther offshore (to 20-30 m depths) at night, 

 where they feed (Hobson and Chess 1976; Hobson 

 et al. 1981; Allen and DeMartini 1983) and perhaps 

 spawn (DeMartini and Fountain 1981). 



This study represents part of an ongoing en- 

 vironmental impact assessment of the fishes of 

 coastal waters off San Onofre Nuclear Generating 

 Station near Oceanside, Calif., using the 

 queenfish as a target species. Recognition of poten- 

 tially complex patterns of spatial and temporal 

 distribution has general applicability for the de- 

 sign and interpretation of analogous monitoring 

 studies and for other assessments of nearshore fish 

 stocks (June 1972). 



METHODS AND MATERIALS 



Sampling Design 



Catches made by lampara seines (a type of 

 semipursing, roundhaul net, Scofield 1951) were 

 used to characterize the distribution and abun- 

 dance of queenfish in terms of catch per unit effort 

 (CPUE), where a standard-area seine-haul was 

 defined as the unit of effort (Allen and DeMartini 

 1983). All queenfish present in each seine-haul 

 were counted aboard ship. Seines fished from sea 

 surface to seabed over bottom depths from 5 to 27 

 m. For diel comparisons, a total of 14 pairs of "day" 

 (1-6 h after sunrise) and "night" (1-6 h after sunset) 

 cruises were made during the period from Sep- 

 tember 1979 to March 1981, inclusive. On each 

 cruise, 1 or 2 seine-hauls were made within ran- 

 domly selected subareas within each of three 

 depth blocks (shallow, 5-10 m, 0.5-1.5 km offshore; 

 middepth, 11-16 m, 1.5-2.5 km offshore; deep, 18-27 

 m, 2.5-3.5 km offshore) at each of two longshore 

 locations, about 5 and 22 km upcoast of Oceanside, 

 Calif. Two replicate hauls were made at each 

 longshore location in the shallow depth block 

 (wherein catches were most variable) on day 

 cruises, and the two catch values averaged. For a 

 chart of the study area and further details of gear 

 and sampling designs, see Allen and DeMartini 

 (1983). 



CPUE and Size-Composition Data 



A maximum of two subsamples of —50 individu- 

 als each of queenfish of all sizes were randomly 

 selected from each seine-haul and placed on ice 



172 



aboard ship. In the laboratory, all fish in the sub- 

 samples were sexed macroscopically (DeMartini 

 and Fountain 1981) into immatures (of both sexes), 

 adult males, adult females, and sex indetermin- 

 able. (Fish of indeterminable sex comprised <5% 

 of total catch.) Fish were measured to the nearest 

 millimeter standard length (SL) and grouped into 

 5 mm length classes for analysis. For seine-hauls 

 in which the total number of queenfish caught 

 exceeded the total number measured, the numbers 

 of fish of each maturity and sex category caught 

 were estimated from the respective number mea- 

 sured, standardized to the total number of 

 queenfish caught. In these cases, the length fre- 

 quencies of the fishes in each sex category mea- 

 sured were then weighted by the estimated 

 number of that category present in the haul. 



Queenfish length-frequency data were com- 

 pared between diel periods and depth blocks by 

 Kolmogorov-Smirnov Two-Sample test (Siegel 

 1956). A nonparametric 3-way ANOVA (Wilson 

 1956), available in the IMSL Library's^ statistical 

 package, was used to simultaneously evaluate the 

 effects of diel period, depth block, sampling date 

 (cruise), and their potential interactions on the 

 numerical CPUE of immature, adult male, and 

 adult female fish. In all ANOVA analyses, catches 

 made w.ithin the same depth block at the two long- 

 shore locations on a given cruise were considered 

 separate estimates, as differences between loca- 

 tions were sometimes evident. 



Food Habits 



Additional subsamples of one queenfish per 10 

 mm SL length class were randomly selected from 

 seine-hauls for analysis of food habits. Fish were 

 examined from a larger series of 11 day and 23 

 night cruises (that included 8 of the aforemen- 

 tioned 14 paired, day/night cruises) conducted 

 during September 1979-October 1980. These sub- 

 sampled fish were placed in lO^c Formalin'* 

 immediately following capture, after their abdom- 

 inal walls had been slit to accelerate preservation. 

 Stomachs were dissected and placed in 70% ethyl 

 alcohol after about 1 wk of fixation. Contents of 

 stomachs were scored for state of digestion on a 

 scale of (undigested) to 10 (prey present but to- 

 tally indistinguishable). All prey were identified 

 to lowest taxonomic category, their numbers tal- 



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■* Reference to trade names does not imply endorsement by the 

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