ON DIFFERENT FACTORS IN FORMATION OF ACOU STIC BOUNDARIES AND SOUNDSCATTERING LAYERS IN SOUTH-WEST BALTIC

Soundreflecting boundaries and soundscattering layers, connected with gradient layers were discovered in South West Baltic with the and of a nechosound Soundreflecting at three different depths, In two upper lay ers the following factors were important for their origination: micros tructure inhomogeneities of sea medium, biomass and suspended matter. In the lower depth the suspended matter factor was the most important.