Voloshchuk E. V., Maximov A. A.
Benthic organisms can significantly influence the geochemical processes in the sediments by digging burrows and tunnels, which are then destroyed or backfilled, by absorption and excretion of sediments, plowing of surface soil etc. This work is dedicated to assessment of influence of invasive polychaetes Marenzelleria arctia activity on organic carbon content, total contents of iron and manganese in the solid phase of bottom sediments in the Eastern part of the Gulf of Finland. The content of chemical compounds in the sediments, abundance and biomass of polychaetes were obtained during the research cruise of RSHU in July 2016. Statistical analysis of field data allowed to reveal the peculiarities in distribution of chemicals depending on polychaetes population. Stations with higher polychaetes density were found to correspond to the lower content of organic matter, iron and manganese in the solid phase of sediments. In contrast, at stations with low Marenzelleria population the contents of these substances are higher. It can be concluded that bioturbation activity of polychaetes increases organic matter mineralization and reduces its burial, and also, probably, contributes to a more intensive consumption of Fe and Mn oxides/hydroxides in organic matter oxidation.