LOVE ET AL.: INSHORE SOIT SUBSTRATA FISHES IN SOUTHERN CALIFORNIA BIGHT CalCOFl Rep., Vol. XXVII. 1986 INSHORE SOFT SUBSTRATA FISHES IN THE SOUTHERN CALIFORNIA BIGHT: AN OVERVIEW MILTON S. LOVE, JOHN S. STEPHENS, JR., PAMELA A. MORRIS, MICHAEL M. SINGER Occidental College Vantuna Research Group Moore Laboratory of Zoology Los Angeles, California 90041 MEENU SANDHU TERRY C. SCIARROTTA Los Angeles County Natural History Museum Southern California Edison Company 900 Exposition Boulevard System Planning and Research Los Angeles, California 90007 i? 0. Box 800 Rosemead. California 91770 ABSTRACT dominaron a 6.1 m de profundidad. Frente a Ormond, A series of bimonthly trawls was made at stations off S. politus y G. lineatus fueron las especies mas impor- three areas (Ormond Beach, Redondo Beach, and San tantes hasta 18.3 m. Sin embargo, frente a Redondo y Onofre) in the Southern California Bight. Three depths San Onofre, estas dos especies fueron menos comunes (6.1, 12.2, and 18.3 m) were sampled from 1982 to en aguas profundas, siendo reemplazadas por un 1984. At all three areas, queenfish (Seriphus politus), conjunto de lenguados (especialmente Citharichthys white croaker (Genyonemus linearus), and northern srigmaeus, Pleuronichthys verticalis, y Xystreurys anchovy (Engraulis mordax) dominated the 6.1-m sta- liolepis). Sin considerar las variaciones estacionales y tions. Off the Ormond area, queenfish and white anuales, las abundancias de peces disminuyeron en croaker were the important species out to 18.3 m. profundidad frente a Redondo y a San Onofre aun However, off Redondo and San Onofre, these two spe- cuando permanecieron constantes en Ormond. Este cies became less dominant in deeper water, giving way ultimo fendmeno se debi6 al gran numero de S. politus to an assortment of flatfishes (particularly speckled y G. linearus presentes a todas profundidades. Las sanddab, Citharichthys stigrnaeus; hornyhead turbot, abundancias promedio de peces de un ano o mas (con la Pleuronichthys verticalis; and fantail sole, Xystreurys excepcion parcial de G. lineatus y S. politus) dismi- liolepis). Disregarding seasonality and yearly varia- nuyeron durante el period0 de tres anos, especialmente tion, we found that fish abundances off Redondo and entre 1983 y 1984. La abundancia de algunas especies San Onofre decreased with depth, but remained aumento, en particular la barracuda S. argentea y P. constant at Ormond. This latter phenomenon was due ritteri. Aun cuando el reclutamiento de algunas to large numbers of queenfish and white croaker found especies, como por ejemplo C. stigmueus e Hyper- throughout the Ormond isobaths. For fish one year of prosopon argenteurn, disminuy6 entre 1982 y 1984, age and older (with the partial exception of white otras especies (incluyendo a S. politus, E. mordax, S. croaker and queenfish), there was a decline in mean argentea, y P., ritteri) parecieron no ser afectadas e abundance over the three-year period, particularly inluso favorecidas durante el evento El Nino. from 1983 to 1984. There was an increase in abundance of some species, notably California barracuda INTRODUCTION (Sphyraena argentea) and spotted turbot (Pleuronich- Knowledge of fish assemblages within the Southern rhys ritreri). Though recruitment of some species such California Bight is uneven. A considerable amount is as speckled sanddab and walleye surfperch (Hyperpro- known about pelagic assemblages, both offshore (Mais sopon argenteum) declined from 1982 to 1984, a 1974) and nearshore (Allen and DeMartini 1983). number of species (including queenfish, northern There have been numerous surveys of inshore rocky anchovy, California barracuda, and spotted sanddab) reef communities (Ebeling et al. 1980; Stephens et al. appeared relatively unaffected or even enhanced dur- 1984; Larson and DeMartini 1984), and something is ing the El Nino event. known of the soft substrata fishes from 18 m down to about 900 m (Fitch 1966; Mearns 1979; DeMartini and RESUMEN Allen 1984; Cross'). There are no published studies on Una serie de arrastres bimestrales fue realizada en tres fish assemblages from the shallowest (< 18 m), open- areas (Ormond Beach, Redondo Beach, y San Onofre) coast, soft substrata habitats. In 1982 we initiated a en la Bahia del Sur de California. Tres profundidades survey of this inshore habitat. This report describes the (6.1, 12.2, y 18.3 m) fueron muestreadas en 1982- results of this survey from 1982 to 1984. 1984. En las tres areas, Seriphus politus, Genyonernus lineatus y la anchoveta del norte, Engruulis mordax, 'Cross. J. MS. Fi\hes ofthe upper continental \helfoff \outhem Califbrnia 84 LOVE ET AL.: INSHORE SOFT SUBSTRATA FISHES IN SOUTHERN CALIFORNIA BIGHT CalCOFl Rep., Vol. XXVII. 1986 NTURA 1 iAN ONOFRE N LIGHT Figure 1 Location of trawling sites within the Southern California Bight Sampling was conducted in three areas 7 Ormond, 2, Redondo. 3, San Onofre Dark ovals indicate the stations-three each along the 6 1-. 12 2-. and 18 3-m isobaths in each area METHODS TABLE 1 Sampling was conducted bimonthly from February Latitude and Longitude of Trawling Stations within the Southern California Bight 1982 to December 1984 off three areas-designated San Onofre, Redondo, and Ormond (Figure 1). Within Depth each area were trawling stations-three each along the Area Station (m) Latitude (N) Longitude (W) 6.1-, 12.2-, and 18.3-m isobaths (Figure 1). In the San Ormond Ventura 6.1 34" 16.20' 119"18.34' Onofre area the stations were San Mateo Point, San 12.2 34" 16.03' I19"I8.50' Onofre, and Don Light; in the Redondo area they were 18.3 34"15.70' 119"18.74' Mandalay 6. I 34O13.16' 119"15.72' Torrance, Redondo, and Venice; and in the Ormond 12.2 34'13.18' 119"16.20' area they were Ormond, Mandalay, and Ventura. Table 18.3 13"13.19' 1 lY"17.43' 1 gives precise locations of these stations. Because the Ormond 6.1 34O06.87' I19"09.41' study focused on area rather than station, we grouped 12.2 34"06.73' I19"09.61' our results by area. Throughout the paper the word 18.3 34"06.30' I19O09.99' Redondo Venice 6. I 33'58.64' I I8"28.20' location is used interchangeably with ureu. 12.2 33O58.40' 1 IX"28.82' Each survey consisted of two replicate trawls per 18.3 33"58.25' 1 18'29 .24' day, for two successive days, at each depth and station. Redondo 6.1 33"s I .89' 118'24.39' As an example, during the February 1982 survey, we 12.2 33"5 I .76' I18"24.79' made four trawls at 18.3 m off San Mateo Point over 18.3 33"SI .81' I I8"24.95' Torrance 6. I 33O49.79' 118O23.56' two days, two trawls per day. Sampling was conducted 12.2 33'49.90' 11823.72' during daylight hours with a 7.6-m semiballoon otter 18.3 33O49.43' I I8O24.44' trawl towed at two knots for five minutes. Trawls were San Onofre San Mateo 6.1 33"23 .SO' I17"25.11' made along an isobath parallel to shore, in an upcoast 12.2 33'23.20' I I7"36.70' direction. All fishes collected were identified (based 18.3 33O22.96' 11797.13' San Onofre 6.1 33'21.19' I17"32.71' on Miller and Lea 1972), counted, and measured (stan- 12.2 33O20.47' I17O34.34' dard length). 18.3 33"2 I .09' 117"34.01' We used the index of community importance (ICI; Don Light 6.1 33" 19.2 I ' I17"30.43' Stephens and Zerba 1981) to estimate each species' 12.2 33" 18.83' I17"30.95' contribution to its assemblage. ICIs were determined 18.3 33" 18.35' I I7"3 I .52' 85 LOVE ET AL.: INSHORE SOFT SUBSTRATA FISHES IN SOUTHERN CALIFORNIA BIGHT CalCOFI Rep., Vol. XXVII. 1986 in the following way. For each assemblage, species though taken in high numbers, was encountered in were ranked by percent abundance and percent fre- about one-third of all trawls, far less often than S. quency of occurrence. For each species, the two ranks politus or G. linearus. When E. rnordax was captured, were summed, and the species were reranked based on it was often found in large numbers, as many as 7,000 that sum. The respective ICIs were the sum of the two per trawl. Both walleye seaperch (Hyperproscipon ranks. We compared the top ten species from each as- argenteum) and California halibut (Par-alichthys semblage with Kendall’s coefficient of concordance californicus), though taken in comparatively low num- and Kendall’s tau coefficient (Siege1 1956). bers, were caught with greater frequency. We tested whether there was an overall seasonal 12.2 m. Compared to 6.1 m, slightly more species abundance pattern by using a crossed analysis of vari- (87) but far fewer individuals (53,594) were captured ance, performed on the log-transformed data for fish along the 12.2-m isobath (Table 3). Some midwater abundance (raw count + 1) (Afifi and Azen 1979). species, particularly S. politus and G. lineatus, were Fixed model was assumed with main effects being again very important constituents of this assemblage. location, year, and season, with season nested within However, benthic fishes (flatfishes and the California year. Type 111 sum of squares was used so that compar- lizardfish, Synodus lucioceps) gained in importance ison of main effects could be made even in the presence among the top ten IC1 species. of interactions (Freund and Littell 1981). Seriphiispolitus and G. lineatus composed 76.8% of Using all data, we noted large interactions, which all fish taken. However, S. politus was not the over- implied that there was no overall seasonal pattern.