FISHERY BULLETIN: VOL. 82. NO. 1 



Table 2. — The 30 most abundant food items consumed by blacksmith, Chromis punctipinnis , at the dis- 

 charge (thermal outfall) and the Point (control site), King Harbor, Calif. Foc= frequency of occurrence; 

 IRI = index of relative importance. 



TABLE 3. — Usage and availability of selected prey items from the 

 Point (control site) and discharge (thermal outfall), King Harbor, 

 Calif. 



'Mean number of prey consumed per fish. 

 2 Mean number per 100 m 3 of water sampled. 



3 Note: The statistical package (SPSS) used was unable to compute P values low- 

 er than 0.001 . Values below this number are represented as P <0.001 , 



did not overlap (a = 0.522, with a value >0.60 con- 

 sidered significant, Zaret and Rand 1971). 



DISCUSSION 



Blacksmith were a numerically dominant species at 

 both study sites. The daytime abundance of black- 

 smith was similar at the discharge and the Point. 

 Blacksmith may travel to the discharge from the 

 breakwater and other nearby jetties during the day, 

 since they do not seek shelter around the discharge at 

 night. Such diel migrations of blacksmith between 

 the Units 7 and 8 intake of Southern California 

 Edison's Redondo Beach Station and the nocturnal 

 rocky shelters at the Point have been previously 

 observed. 6 



The feeding habits of blacksmith were significantly 

 different between the Point and discharge (Figures 2 

 and 3 best illustrate this difference). At the Point, 

 Oikopleura and calanoid copepods (primarily Acar- 

 tia) were the most heavily utilized organisms. At the 

 discharge, blacksmith consumed larger organisms, 

 gammarids, calanoid copepods of the genus Calanus, 



6 M. Helvey, VANTUNA Research Group, Occidental College, Los 

 Angeles, CA 90041, pers. commun. 1980. 



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