Vertical distribution of the macroinfauna associated to bivalves in a sedimentary intertidal flat of southern Chile

摘要

The community structure of the macroinfauna inhabiting intertidal flats, as well as its distribution inside the sediment column, can be influenced by a combination of physical and biological factors. The objective of this study was to evaluate the vertical distribution and the community structure of the macroinfauna associated to sediments containing razor clams (Tagelus dombeii), during February and September, 2004 on the intertidal flat of Pelluco, Southern Chile. Sediment and macroinfauna samples were collected from sites with and without bivalves, using plastic cylinders divided into 5 equal parts. During both sampling months, the total number of species and the total abundance and biomass of the macroinfauna reached, in almost all sedimentary layers, higher values in the site with T. dombeii. In both sampling months, the faunistic composition was significantly different between sites with and without T. dombeii. In addition, the similarity in the faunistic composition between sedimentary layers was higher in the site with T. dombeii. The results of this study suggest that the bioturbation process of T. dombeii affects the vertical distribution of the associated macroinfauna and that this effect would not be dependent on the time year.