CHARACTERISTICS OF THE BRISTLEWORM (PYGOSPIO ELEGANS CLAPAREDE) (SPIONIDAE) AND ITS ROLE IN THE POLISH COASTAL ZONE OF THE BALTIC SEA

Abstract

Quantitative aspects of the spionid polychaete Pygospio elegans population in the Polish coastal zone of the Baltic Sea, in estuarine areas of Pomeranian river mouths were investigated. The frequency of occurrence (F) of P. elegans in the Polish coastal zone averaged 54% (permanent species) and ranged from 20 to 80%. The polychaete abundance along the Central Pomeranian coast peaked at 1 837 ind. m^-2, the mean abundance being 175.7 ind. m^-2. The density of the spionid worm in the Middle Pomerania was low and rarely exceeded 1 000 ind. m^-2. The mean wet weight biomass of P. elegans in different areas was low (max. 0.29 g_ww m^-2). The abundance of P. elegans in the river mouth areas (estuaries) was basically higher west of the mouth, in areas less exposed to polluted and freshened riverine water; water in those areas, however, carried lower bioseston loads, which affected trophic conditions.

Key words: coastal zone, Baltic Sea, Pygospio elegans