Table 1.-- Summaries of daily metabolism. 



Gross Primary Net Community 



Productivity Primary Productivity Respiration (-) 



(g0 2 /m 2 /day) (g0 2 /m 2 /day) (g0 2 /m 2 /hr) 



Means 



46.7 



9.2 28.7 0.5 2.8 



10.6 72.4 0.5 3.7 



10.5 55.7 



15.0 78.9 0.3 3.6 



7.2 41.0 0.7 3.2 



Jan. 17.3 40.2 10.9 22.0 0.6 1.8 



i May 20.4 59.8 8.1 32.0 1.2 2.8 



cu 



Q. 



50.9 7.9 26.3 



It Aug. 17.6 64.7 3.6 32.7 1.4 3.2 



03 



Oct. 17.5 38.8 9.2 18.5 0.8 2.02 



daytime primary productivity (NPP), and respiration (R) for each reef at each 

 season appear in table 1. Back reefs are more productive than fore reefs. A 

 mean annual GPP of about 17.5 g C/m 2 /d is recorded at Isaac Reef, 19 g C/m 2 /d at 

 Halfpenny Reef, and 33 g C/m 2 /d at Robin Reef (with a mean maximum value of 43.2 

 g C/m 2 /d recorded in August and a mean all-reef productivity of 8500 g C/m 2 /yr). 

 These values are based on a conversion ratio of 0.375 g C/g0 2 with a metabolic 

 quotient for reefs of 1.1 (Marsh and Smith, 1978) applied to the means in table 



172 



