Live benthic foraminifera from the Volturno River mouth (central Tyrrhenian Sea, Italy)

Abstract

Living benthic foraminiferal assemblages were investigated at 22 marine stations in front of the Volturno River mouth (Gulf of Gaeta, central Tyrrhenian Sea), during 3-years survey (2012–2014). The results were compared with the oceanographic data recorded at the same sites, to highlight the ecology of the main dominant species and the relationship between the community structures and the environmental variables (turbidity, dissolved oxygen content, salinity, temperature, and runoff). The living assemblage, analyzed in the top 1 cm of sea floor, was characterized by three dominant species (Ammonia tepida, Bulimina elongata, and Rectuvigerina phlegeri) during all the sampling periods. Correlation analysis identified turbidity, runoff, and oxygen as the main environmental factors influencing living foraminiferal assemblages. Ammonia tepida and Rectuvigerina phlegeri showed opportunistic behaviour in response to turbidity, oxygen, and salinity values. No significant correlation was recorded between Bulimina elongata and the environmental parameters, testifying the capability of this species to adapt to different environmental conditions. The occurrence and distribution of these species provided useful information about coastal dynamics and sediment transport, and our results confirmed them as reliable proxies of coastal water column turbidity and Volturno river basin runoff.