III-A-10 



Darnell, R.M. 1967. Organic detritus in relation to the estuarine ecosystem. 



Pages 376-382 i£G.H. Lauff, ed.. Estuaries. American Association for the 



Advancement of Science, Washington, D.C. 



This paper explores the processes of biological decomposition of 

 estuarine detritus and examines non-nutritive as well as nutritive 

 roles. The author defines organic detritus as all types of biogenic 

 material in various stages of microbial decomposition, which represents 

 potential energy sources for consumer species. Two states are recognized: 

 the particulate and subparticulate. The author discusses estuarine 

 detritus in relation to turbidity, sedimentation, and nutrition. 



It was determined that particulate organic detritus is everywhere 

 abundantly available, that it is ingested in quantity by zooplankton, 

 fishes, and benthic invertebrates, and that areas of zooplankton 

 abundance are correlated with centers of detritus abundance rather than 

 with phytoplankton abundance. Such results lead one to suspect causation, 

 but whether the relation is direct or indirect is not yet known. 

 There can be little doubt that in most estuaries particulate organic 

 detritus is abundant and is consumed in great quantities. 



The author concludes that most organic detritus is of vegetable origin. 

 Since few of the larger estuarine consumers feed upon vegetation alone, 

 the real primary consumers of the community are the microbial species 

 (decomposers). Although the trophic efficiency of microbes has not yet 

 been determined, it is apparent that some energy is lost in passage 

 through the microbial scheme. Since most of the larger consumers of 

 the estuarine community are omnivores, their relative trophic positions 

 can be assigned only by determining the percentage contributions of 

 energy from each food source. (H.D.) 



Keywords: detritus, productivity, estuaries, decomposition 



III-A-11 



Heald, E.J., and W.E. Odum. 1969. The contribution of mangrove swamps 



to Florida fisheries. Proceedings of the Gulf and Caribbean Fisheries 



Institute 22:130-135. 



The primary food source for aquatic organisms in many shallow estuaries, 

 particularly those at lower latitudes, is not phytoplankton but vascular 

 plant detritus. In south Florida, the red mangrove ( Rhizophora mangle ) 

 and turtle grass ( Thalassia testudinum ) are the primary sources of 

 detritus. 



This paper discusses the importance of mangrove swamps to the ecology 

 of south Florida estuarine areas from the perspective of detritus 

 production. The pathways by which the primary production of these 

 plants is ultimately utilized by species of commercial value are described. 



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