Rôle des facteurs environnementaux et anthropiques dans la fluctuation saisonnière de l’organisation trophique de la macrofaune benthique dans la lagune de Boughrara (Sud-Est de la Tunisie), après l’extension de la passe de communication d’El-Kantra

Abstract

The lagoon of Boughrara is the largest lagoon in Tunisia. For several decades it has been subject to the impact of increasing anthropogenic activities, and also to environmental stressors. The present work is a contribution to the study of the functional organization of the benthic macrofauna of the lagoon of Boughrara a few years after the extension of the El-Kantra channel which connects this lagoon to the open sea. In total, 13 stations facing the main prospective sources of disturbance were seasonally sampled during 2009-2010 and 2012-2013. Obtained results show that the benthic macrofauna community is generally poorly diversified at lagoonal-marine stations undergoing influences of both the marine and lagoon environment. The structure of the benthic macrofauna showed an important regression in number of species and in number of individuals during the seasons of the second period of study. The trophic organization, in turn, showed a clear seasonal fluctuation, but it still remains dominated by selective deposit feeders and appears to be more related to the availability of food resources than to disturbances.