154 



NOAA Technical Report NMFS 140 



the temperature range broadened. This trend was very 

 pronounced. Their density was 0.3/m 1 ' where the temper- 

 attire range was nil or small. Their density steadily increased 

 to 196/irr where the temperature range was greatest. 



Biomass similarly showed a marked increase in rela- 

 tion to increased temperature range. The range in 

 average biomass was from 0.05 to 20.32 g/m , the ex- 

 treme values occurring in the two extreme temperature 

 range classes (Table 23; Fig. 152). 



Frequency of occurrence of cirripedes was rather low 

 (2 to 5% of the samples) in all temperature range 

 dasses except the highest (20°-23.9°C), where a mod- 

 erate (18%) incidence rate was obtained (Table 25). 



Relation to Sediment Organic Carbon 



There was a distinct bimodal relationship of cirripede 



abundance with regard to organic carbon content of 



the sediment. This was especially apparent in terms of 

 densitv. Moderate densities (19 and 39 individuals/m 2 ) 

 occurred in the two carbon content range classes be- 

 tween 0.01 and 0.99%; none occurred in content classes 

 between 1.00 and 1.99%; but density increased dra- 

 maticallv to 613/m 2 where carbon content was from 

 2.00 to 2.99%, and was moderately high (83/rrr) in car- 

 bon contents between 3 and 5% (Table 26; Fig. 153). 



Biomass displaved a similar trend but not as dramati- 

 cally. Moderate biomass (6.5 and 4.1 g/m L> ) occurred in 

 the two range classes between 0.01 and 0.99%. with 

 highest biomass (14.3 g/m L> ) in the 2.00 to 2.99% class 

 (Table 28; Fig. 153). Lowest biomass was in the highest 

 organic content class. 



Frequency of occurrence of barnacles was moderate 

 (3 and 6%) in the lower level organic carbon content 

 classes but was moderately high (15 and 25%) in the 



