The flow cytometry, a new tool for trophic coastal ecosystem diagnostic

The aim of this study is to develop a synthetic ecological index from phytoplanktonic data. An ecological index was developed from 78 flow cytometric data sampled in four sites (3 in Madagascar and I in Mozambique) and 108 samples (2 malagasy and 1 moroccan sites) for validation. This index describes the trophic level, the microbial loop activity and the stability of the system. According to several coastal phytoplanktonic ecological studies, this index defines the ecological status of the micro-ecosystem studied in 62.96% of the cases. The validation, made with lagoonal Mediterranean data, allows to extend the application area from the inter-tropical zone to the Mediterranean coasts. (C) 2004 Elsevier Ltd. All rights reserved.