MICROHABITAT PREFERENCES OF LIVING (STAINED) BENTHIC FORAMINIFERA FROM EXPERIMENTAL BANKS IN THE VENICE LAGOON

This study is part of an ongoing project (SIOSED) to determine the effects of sediment translocation caused by dredging in the Venice Lagoon, Italy. Two experimental banks were created in November 2005 to examine the biological and biogeochemical effects of creating artificial banks with dredged sediments. For the purposes of this study, the banks have been monitored in order to determine sediment translocation effects on heavy metal behavior and benthic ecologies. Vertical distribution profiles of living (Rose Bengal stained) benthic foraminifera (>150µm) have been examined from cores taken every six months since the banks were created. Push cores taken in May 2007 show differences in the microhabitat preferences and percentages of aberrant morphologies of dominant taxa in the lagoon. Dominant taxa include: Ammonia parkinsoniana, Ammonia tepida, Haynesina germanica, Aubignyna perlucida, Ammonia spp., Quinqueloculina spp., and Eggerelloides spp. Differences in the vertical distribution profiles of different species represent different ecological preferences among the species. Differences in the percentages of aberrant morphologies provide important information regarding the influence of heavy metal contamination on benthic foraminifera. These results contribute to our understanding of the influence of sub-tidal banks on benthic communities in the Venice Lagoon.