The Oliveri-Tindari lagoon: evolution of the trophic-sedimentary environment and mollusc communities in the last twenty years

In the present study the evolution of the benthic ecosystem of Oliveri-Tindari (Messina, northern coast of Sicily), is described through the examination of data collected every ten years, from 1978 up to now. In particular three cycles of investigations (1978, 1987, 1997) provided comparable information on the edaphic, trophic and biological characteristics of the area. As shown, there as been a constant rise in the fine sedimentation occurring in the pools during these twenty years. With regard to the trophic characteristics, a general decrease of the organic carbon content in the sediments was recorded in the second cycle of study. The trophic-sedimentary evolution caused marked changes in the structure of the benthic communities, as pointed out by the qualitative and quantitative variations. In general a decrease in the density of the mollusc benthic communities was observed, because of the progressive isolation of the pools.