FISHERY BULLETIN: VOL. 80, NO. 4 



1973; Haedrich and Haedrich 1974; Targett and 

 McCleave 1974; Livingston 1976; Moore 1978; 

 Shenker and Dean 1979; Orth and Heck 1980). 

 Although quantitative in nature, many of these 

 investigations suffer from the inefficient (Kjel- 

 son and Johnson 1978) trawl sampling gear used 

 and the high mobility of most fishes. Adams 

 (1976a, b) used dropnet samples to accurately 

 assess the density and productivity of the fishes 

 of two North Carolina eelgrass beds. Weinstein 

 et al. (1980) used a combination of block nets, 

 seines, and rotenone collections to derive accu- 

 rate quantitative estimates of fishes in shallow 

 marsh habitats in the Cape Fear River Estuary, 

 N.C. 



Previous investigations of fishes in Newport 

 Bay have included a species list (Frey et al. 1970), 

 a general species account (Bane 1968), two indi- 

 vidual species accounts (Fronk 1969; Bane and 

 Robinson 1970), and two studies on the popula- 

 tion ecology of the fauna based on juveniles and 

 adults (Posejpal 1969; Allen 1976). An assess- 

 ment of the ichthyoplankton and demersal fish 

 populations during 1974-75 (Allen and White in 

 press) is the most comprehensive work to date. 



Despite these studies, a substantial component of 

 the ichthyofauna, the littoral fishes of the upper 

 bay (0-2 m depth from mean higher high water), 

 had not been adequately sampled. In a study of 

 the demersal ichthyofauna of Newport Bay dur- 

 ing 1974-75 (Allen 1976), I found that three— 

 Atherinops affinis, Fundulus parvipinnis, and 

 Cymatogaster aggregata — of the five most numer- 

 ous species were the ones that occurred in the 

 shallow water over the mudflats which cover 

 about 60-70% of the surface area of the upper bay 

 reserve. Despite their high numerical ranking, 

 the relative abundances of these littoral species 

 were underestimated because sampling was car- 

 ried out almost exclusively by otter trawls in the 

 deeper channels of the upper bay. The recogni- 

 tion of this gap in our knowledge served as the 

 impetus for the present study. 



The main purposes of this study were to char- 

 acterize the littoral ichthyofauna of upper New- 

 port Bay quantitatively by 1) composition and 

 principal species, 2) diversity and seasonal dy- 

 namics, 3) productivity, and 4) key environ- 

 mental factors that are influencing this fish 

 assemblage. 



SHEILMAKE* 

 ISLAND 



LOWER BAY 



Figure 1.— Map of upper Newport Bay, Orange County, Calif., 

 with the locations of the three sampling stations. 



METHODS AND MATERIALS 



Study Area 



Newport Bay (lat. 33°37'30"N, long. 117° 54' 

 20"W) is located in Orange County, Calif., 56 km 

 southeast of Los Angeles and 140 km north of the 

 Mexican border (Fig. 1). The upper portion is the 

 only large, relatively unaltered bay-estuarine 

 habitat in California south of Morro Bay (lat. 

 34.5°N). The low to moderately polluted lower 

 portion, commonly called Newport Harbor, has 

 been severely altered by dredging activities, 

 landfills, and bulkheads to accommodate more 

 than 9,000 boats. The study area, the upper two- 

 thirds of the upper bay, is bordered almost com- 

 pletely by marsh vegetation and mudflats. The 

 California Department of Fish and Game pur- 

 chased and set aside this area as an ecological 

 reserve in 1975. 



Three stations, about 0.5 km in length, were 

 spaced evenly along the shore of the upper New- 

 port Bay (Fig. 1). Sampling was stratified based 

 on prior information on the uniqueness of the fish 

 fauna of the three areas (Allen 1976). This design 

 also allowed thorough coverage of the study area. 

 Each station was situated on a littoral (inter- 

 tidal) mudflat area adjacent to marsh vegetation 



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