SOME THOUGHTS ON THE PAST, PRESENT, AND FUTURE OF STUDIES 

 ON CORAL REEF COMMUNITY METABOLISM 



S. V. Smith 

 Hawaii Institute of Marine Biology 

 Kaneohe, Hawaii 96744 



Marjorie Reaka, as editor of these two volumes on The Ecology of Deep 

 and Shallow Coral Reefs , has kindly offered me the opportunity to comment on 

 where I see studies of reef community metabolism to be coming from--and going 

 to. The following thoughts arise as I consider, in particular, the seven 

 papers loosely grouped in "The Organization of Reef Ecosystems" in these 

 proceedings. 



These papers have some aspect of the metabolic performance of coral reef 

 communities or systems as a broad common theme. Within the context of that 

 theme, all of the papers can trace their ancestry back to the "foundation 

 studies" by Sargent and Austin (1949) at Rongelap Atoll and Odum and Odum (1955) 

 at Enewetak Atoll. Earlier papers in the field of reef community metabolism 

 can, of course, be identified. They have tended to remain lost in obscurity 

 compared to the two I have cited. Over the intervening years, the field has 

 matured and expanded sufficiently that citation of these important papers is 

 beginning to drop off. Instead, I recognize increasing proportions of second 

 (or third) generation citations, both in the papers on reef metabolism in these 

 volumes and in the general literature. 



These early papers dealt primarily with oxygen and carbon flux of reef- 

 flat communities. Several of the papers in the present volumes and a survey 

 of the literature suggest that we can move beyond a direct concern with average 

 rates of oxygen and carbon fluxes in studies of reef metabolism. We now can 

 speak with some confidence about the typical oxygen and carbon metabolic 

 performance of reef-flat communities. It is, however, worth noting that we 

 remain without a comparable large data base for other parts of coral-reef 

 ecosystems. 



We are beginning to gain an appreciation for the relationships between 

 variation in reef metabolism and the controlling roles of external physical, 

 chemical, and biological variables. Many casual observations about reef 

 metabolic response to external controls have led to erroneous or trivial 

 conclusions. Clearly, controlled experiments and carefully designed field 

 surveys need to be conducted in order to test hypotheses about metabolic 

 responses to controlling variables. 



The study of nutrient fluxes in relation to community metabolism has, 

 perhaps, been more extensive than other aspects of controls on community 

 metabolism. This work became prominent during the Symbios Expedition to Enewetak 

 Atoll (Johannes, et al  , 1972). Studies of nutrient flux continue, and most of 

 the papers on reef metabolism in these volumes at least touch on this subject. 

 In particular, there is an interest in the effects of both quantity and quality 

 of nutrient supply on reef metabolism and in the interactive roles of various 

 communities (especially macrofauna/meiofauna/microfauna in interreef soft- 



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