FISHERY BULLETIN: VOL. 82, NO. 1 



TABLE 2.— Southern California ichthyoplankton collection 

 sites, August 1979-July 1980. Location abbreviations used 

 in Figures 13-15 are in parentheses. 



doors over the mouth openings. The canvas doors 

 were removed by a cable messenger, allowing the 

 nets to fish. Immediately thereafter the sampler was 

 retrieved at a constant rate of about 10 m/min (0.17 

 m/s); a wire angle of 51 ± 5° was maintained. The 

 ship's speed (0.95 ± 0.03 m/s) plus the retrieval rate 

 brought the net speed to about 1.12 m/s. 



In addition, stratified (surface, midwater, bottom) 

 tows were made at each of the four stations on tran- 

 sects at Ormond Beach, Redondo Beach, and San 

 Onofre. Horizontal midwater tows were made with 

 the previously described bongo sampler towed at a 

 rate of 1.06 ± 0.06 m/s. For these tows the sampler 

 was lowered to a depth about half-way between the 

 surface and the bottom, opened via cable messenger, 

 fished, closed via cable messenger, and retrieved. 

 Surface samples were taken with a manta sampler 

 (Brown 1979) towed at a rate of 1 .07 ± 0.06 m/s. This 

 net had a rectangular opening (88 X 16 cm). Bottom 

 collections were taken using an auriga net 6 with a 200 

 X 50 cm mouth. The auriga net fished a zone 2 mwide 

 by 0.5 m deep, about 0.25 m above the substratum, 

 and was fished at a rate of 1.07 ± 0.46 m/s. All nets 

 were equipped with 335 ju mesh. A General Oceanics 

 flowmeter was mounted in the mouth of each net. The 

 field program is described in greater detail by Laven- 

 berg and McGowen. 7 



Additional data from a 4-yr study off Redondo 

 Beach were derived from monthly surface tows made 

 from January 1974 to February 1977, using meter 

 nets with 335 /i mesh. A TSK flowmeter was mount- 

 ed in the mouth of each net. This field program is de- 

 scribed in greater detail by McGowen. 8 



Fishery 



Although white croaker are usually the most impor- 

 tant species in the private vessel sportfishery, no 

 size-frequency data were available. For this reason, 

 4,941 croaker taken by anglers aboard skiffs and 

 other small private vessels were measured during the 

 period June 1980 to July 1981, between Oxnard and 

 Dana Point. From September 1980 through August 

 1981, 1,748 white croaker were taken off southern 

 California by commercial gill net vessels and were 

 measured. 



RESULTS 

 Depth Preference 



Our trawling study indicated that white croaker pre- 

 ferred nearshore habitats and their abundance 

 declined in deeper waters. Ranking first of all species 

 taken, white croaker was the dominant species at the 

 shallowest (18-27 m) stations (Table 3), and com- 

 posed 29.7% by number of the total catch and 

 appeared in 68% of the trawls. At the 59-73 m 

 stations, white croaker catches had declined to 3.3% 

 of total catch, frequency of occurrence 20.7%, and at 

 the 91-109 m station, the species made up 1.2% of 

 total catch, frequency of occurrence 14.0%. At 

 stations between 165 and 183 m, white croaker com- 

 prised 0.6% of the total catch, with a frequency of 

 occurrence of 1.7%. On the basis that no individuals 

 were captured at greater depths, we accept 183 m as 

 their maximum depth. 



Though white croaker was supplanted as the domi- 

 nant species at deeper stations, it remained an 

 important community component to depths of 109 

 m. Two other species, the California tonguefish, 

 Symphurus atricauda, and the Pacific sanddab, 

 Citharichthys sordidus, were among the 10 most 

 abundant species throughout these depths. Pacific 



''Mitchell, C. T. Auriga: A wheeled epibenthic plankton sampler 

 for rocky bottoms. Unpubl. rep., 12 p. Marine Biological Con- 

 sultants Inc., 947 Newhall Street, Costa Mesa, CA 92627. 

 'Lavenberg, R. •!.. and (1. E. McGowen. Coastal ichthyoplankton 



of the Southern California Right: temporal and spatial distribution 

 (Augusl 1979-July 1980). Manuscr. in prep. Los Angeles County 

 Museum of Natural History, 900 Exposition Blvd., Los Angeles, 



CA 9 7. 



8 McGowen, G. E. 1978. Effects of thermal effluent from 

 Southern California Edison's Redondo Beach steam generating 

 plant on the warm temperate fish fauna of King Harbor 

 Marina. SCE Research and Development Series: 78-RD-47, 65 

 P. 



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