The research vessel Salme undertook a voyage during 14–16 September in the framework of the project „Development and application of methodology required for assessing the state of seabed sediments”. The project is carried out by the Geological Survey of Estonia and is co-financed by the Estonian Environmental Investment Centre.
The impact of this project is directly targeted to the improvement of the environmental state of sea bottom. The methodology for assessing the environmental state of sea areas and the required input data will be supplemented as a result of the project. The basis for applying the methodology is monitoring methodology proposed in the framework of the earlier SedGof project (“Assessment for ecosystem-based management of marine environment on the basis of sea bottom and sediments of the Gulf of Finland”). The SedGof project assessed the state of marine environment in the Gulf of Finland. In the framework of the current research project, assessment of the state of the seabed environment of Estonian coastal waters is being continued by moving from the mouth area of the Gulf of Finland through the region of the Väinameri Sea to the northern part of the Gulf of Riga.
The regions and locations of representative sedimentary cross-sections (for sampling) within this sea area have been chosen on the basis of data from geophysical profiling (seismo-acoustic profiling, side-scan sonar). A GEMAX type sediment corer is used for sampling. Each sediment core will be sampled at the intervals of 2-5 cm. Granulometric composition and concentrations of elements/compounds (Pb, Cd, Cu, As, Hg, Ni, Co, Cr, Sn, Zn, P, U, Ra, Tl, As, Se, Mo, Na, Cl, TN (total Nitrogen) and Corg (organic Carbon)) as well as concentrations of organic matter and nutrients will be determined. It is necessary to date sediments with some radioactive isotope method(s) or determine the amount of a radioactive isotope of a chemical element (e.g. Cesium Cs-137) in the samples for the purpose of assessing the rate of sedimentation both within different sedimentary basins and between different parts of them.
As a result, such methodology and basic data (including map layers) will be compiled, which are required for developing quantitative indicators and assessing methods of Estonian marine areas and for establishing renewed (monitoring) methodology of systematic measurements at monitoring areas.