ABSTRACT: A steady-state model of the planktonic food web of the lagoon of Takapoto Atoll (Tuamotu Archipelago, French Polynesia) was developed to assess the characteristics of that ecosystem. The planktonic food web was divided into 7 compartments, whose carbon biomasses and rates of exchange were determined from field data combined with inverse analysis, the latter being used to estimate missing rates. Results indicate that the system was characterized by high phytoplankton production and, in agreement with previous results, low bacterial production. Due to their high metabolism, metazoan zooplankton played a dominant role in the cycling of carbon. In contrast, the contribution of protozoa was small. The non-living particulate organic carbon compartment also played a key role, qualitatively and quantitatively, because detritus was directly consumed by all heterotrophic compartments.

KEY WORDS: Plankton · Food web · Inverse model analysis · Atoll lagoon · Coral reef · French Polynesia

Published in MEPS Vol. 165 (1998) on May 7
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1998