ASSESSMENT OF BIOTURBATION ACTIVITY OF MARENZELLERIA SPP. IN THE EASTERN PART OF THE GULF OF FINLAND

Abstract

Macrofauna is supposed to influence on physic-chemical characteristics of the sea bottom sediments. Through its bioturbation mechanism porosity, area of oxygenated layer and oxygen penetration depth have increased. This lead to alterations in nutrient cycling as well as improvement in redox conditions which define direction of fluxes in the sediments. In oxic conditions phosphorus is transformed into particulate form and thus, its retention and burial increase. In contrary, denitrification is getting weaker and nitrogen returns into the water. The impact of benthic organisms bioirrigation activity on other chemical components in solid sediments is not sufficiently studied. Present investigations were carried out for the most abundant benthic species in the Gulf of Finland Marenzelleria spp. Those polychaetes are active turbators and their irrigation effect lead to significant changes in chemical compounds in the solid sediment. On the basis of statistical analysis of data on vertical distribution of organic carbon content, total iron and manganese in solid sediments and abundance of Marenzelleria spp. there was found that polychaetes have a significant impact on organic carbon content, while for total iron and manganese such regularity is not revealed.