The influence of Hediste diversicolor (O.F. MÜLLER, 1776) on the macro- and meiozoobenthos of a shallow water area of Mecklenburg Bay (Western Baltic Sea)

Introduction The purpose of many ecological studies is to identify interactions between faunistic ecosystem components by means of laboratory and field experiments. It has often been shown that abiotic and biotic factors such as competition, disturbance and predation influence the composition and dynamics of macrobenthos communities (REISE, 1977; COMMITO and AMBROSE, 1985; AMBROSE, 1986; BEUKEMA, 1987; KIKUCHI, 1987; REDMOND and SCOTT, 1989; COMMITO and BANCAVAGE, 1989; MATILA and BONSDORFF, 1989; HILL et al., 1990). Experiments have also been performed to detect interactions between macrofauna and meiofauna (BELL & Coull, 1978; REISE, 1979; GEE et al., 1985; ALONGI and TENORE, 1985). The interactions between Nereidae and infauna that are common in shallow water and are fairly easily handled have been a major topic of study (COMMITO, 1982; REISE, 1979b; COMMITO and SCHRADER, 1985; OLAFSON and PERSSON 1986; RÖNN et al., 1988). The purpose of our studies was to investigate the influence of the omnivorous H. diversicolor on the infauna of a shallow water region in the southern Baltic Sea. H. diversicolor achieves abundances of between 5,000 and 15,000 ind m" (individual dominances up to 15 %) in the investigation area and is thus a major component of the macrofauna. It therefore seemed likely that its carnivorous feeding habits can affect community structure. To detect direct influences on both the macrozoobenthos and meiozoobenthos and to reduce box effects, we performed short term experiments. ,