(Table 1) Light attenuation in water and concentration, particle size, and composition of particulate matter in the Baltic Sea in July-August 1967

Some aspects of relationship between transparency of Baltic Sea water and composition of particulate matter in it are examined. It is concluded that increase in concentration of particulate matter, rise in content of 0.05-0.005 mm size fraction, and increase in amount of terrigenous particles, as well as increased concentration of dissolved humic substances near river mouths lead to noticeable reduction in transparency.