other Tidal Creek Studies 



Larger Embayments 



Swift and Frantz (1981) sampled 13 

 tidal creeks for adult and juvenile fishes 

 at the highly modified Ballona Wetland. 

 One larger channel (5 to 6 m wide x 1 to 

 1.5 m deep) was sampled for fish eggs and 

 larvae. The authors found that five 

 species comprised 85% of the total adults 

 and juveniles collected. These were arrow 

 goby, mosquito fish ( Gambusia affinis ) . 

 topsmelt, killifish, and longjaw mudsucker 

 in order of relative abundance. Only 1 

 California halibut (a juvenile) and 12 

 diamond turbot (juveniles) were collected, 

 which indicated that this wetland plays a 

 limited role as a nursery ground, in 

 comparison with more natural southern 

 California wetlands (Table 13). 



Plankton tows at the Ballona Wetland 

 yielded only 278 larvae and 439 eggs 

 (Swift and Frantz 1981). Topsmelt 

 dominated the larval fraction, with 226 

 collected. Only 29 individuals, 

 representing 5 taxa of the family Gobiidae 

 were collected. No Sciaenid or topsmelt 

 eggs were identified, and only two 

 northern anchovy eggs were collected. The 

 absence of gobiid species indicates 

 reduced functioning of the area for these 

 resident estuarine species, 



Elkhorn Slough is north of Point 

 Conception; however, its tidal creek fish 

 communities share many similarities with 

 Tijuana Estuary. Data on adult and 

 juvenile fishes (Dickert et al. 1981) 

 indicate that staghorn sculpin, topsmelt, 

 northern anchovy, and arrow goby were 

 dominant. Tidal creeks were thought to be 

 nurseries for sculpin (Cottidae), 

 flounders ( Pleuronectidae) , halibut 

 (Bothidae), and anchovies (Engraulididae) , 

 and breeding areas for herring 

 (Clupeidae), topsmelt, and jacksmelt 

 ( Ather inopsis calif orniensis ) . 



Unfortunately, these functions were not 

 documented by larval or egg sampling. 



Adult and juvenile fishes have been 

 collected from embayments and larger 

 channels from several southern California 

 wetlands (Table 14). These data sets have 

 three similarities: (1) Topsmelt, 

 California killifish, staghorn sculpin, 

 arrow goby, and anchovy species are common 

 dominant species. (2) All of these except 

 the anchovies are considered the main 

 residents. (3) The commercial species 

 most often cited as using wetland channels 

 for nursery grounds are the California 

 halibut ( Paralichthys californicus ) and 

 diamond turbot ( Hypsopsetta guttulata ) . 

 White et al. (unpub.) estimated that 

 30,000 juvenile halibut and 17,000 

 juvenile turbot occurred in the Tijuana 

 Estuary channels. However, this is an 

 extrapolation from five sampling stations. 

 Eggs and larvae of both species were only 

 occasionally found in Tijuana Estuary by 

 Nordby (in prep.), so apparently they 

 breed offshore (cf. Haaker 1975) and enter 

 the estuary as juveniles. Onuf et al. 

 (1978) reviewed the literature for central 

 and southern California fish-wetland 

 dependency and suggested that more 

 northerly estuaries or those of larger 

 area have greater abundances of 

 commercially important species. They cite 

 only information on adult and juvenile 

 fishes, however. The data available for 

 larvae and eggs provide better information 

 on the importance of southern California 

 bays and channels for fish breeding (Table 

 13). 



Four of the embayments examined are 

 small, enclosed wetlands, while San Pedro 

 Bay is a relatively open system 

 encompassing the Los Angeles-Long Beach 

 Harbors. Larvae in all four enclosed 

 wetlands were dominated by a complex of 

 goby species. San Pedro Bay had many more 

 larval species and different dominants, 

 probably due to its greater communication 

 with the open ocean. The contrast between 

 these two wetland types suggests that the 

 smaller, more enclosed wetlands provide 

 different habitat for fish. More recent 

 comparisons of Cabrillo Beach (within Los 

 Angeles Harbor) and nearby Upper Newport 



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